Injection laser

FIELD: physics.

SUBSTANCE: heterostructure-based laser has a waveguide layer enclosed between wide-gap emitters with p and n conductivity type, which are simultaneously bounding layers, an active region consisting of quantum size active layer, an optical Fabry-Perot resonator and a strip ohmic contact with an injection region underneath. In the waveguide layer outside the injection region there is a doped region, where the optical limiting factor of the closed mode in the doped region and concentration of free charge carriers in the doped region satisfy the relationship: where: is the value of the component of the optical limiting factor GY in the amplification region for the closed mode, arbitrary units; is the mode loss at the output of the Fabry-Perot resonator, cm-1; αi is loss due to absorption on free charge carriers in the amplification region, cm-1; Δα denotes losses associated with closed mode radiation scattering on irregularities (αSC), inter-band absorption (αBGL) and absorption on free charge carriers in lateral parts of the injection laser, cm-1; is the closed mode optical limiting factor in the doped region, arbitrary units; n, p denote concentration of free electrons and holes in the doped region, respectively, cm-3; σn, σp denote the absorption cross-section on free electrons and holes in the doped region, respectively, cm2.

EFFECT: high optical power output in both continuous and pulsed modes of current pumping, high stability of the output optical power.

13 cl, 5 dwg

 

The present invention relates to quantum electronic devices, and more specifically to a power semiconductor lasers.

Powerful semiconductor lasers are widely used in many branches of science and technology, for example, are used as the source of optical radiation for pumping fiber amplifiers, fiber and solid state lasers. This requires that the semiconductor laser combines maximum efficiency and power output. The development of new approaches to the design of powerful semiconductor lasers has significantly improved optical properties of heterostructures. For modern semiconductor lasers internal optical loss amount value less than 1 cm-1when the internal quantum yield close to 100%. High optical perfection of laser heterostructures and low optical loss can achieve continuous and pulsed excitation levels of several tens of amperes. The result of such changes the characteristics of laser heterostructures and levels of excitation is the appearance of new effects, some of which leads to saturation of the watt-ampere characteristics and decrease the maximum output power of radiation.

Known injection laser (see patent US 7643527, IPC H05S 5/323 published 05.01.2010), which includes a substrate, characterized by the availability of the m areas with dislocations with a density of 10 5cm-2or more crystalline semiconductor structure located on the substrate and having an active layer. An insulating layer located on a semiconductor structure, the upper ohmic contact is located on the insulating layer and is electrically connected with a semiconductor structure for injection of a current into the active region. The lower ohmic contact is located on the bottom surface of the substrate. The semiconductor laser has an optical cavity of length L and area of the top ohmic contact 120·L μm2or less.

The disadvantages of the proposed injection laser is the lack of technical solutions to suppress the generation of a closed-loop fashion. In the optical output power of the proposed semiconductor laser does not reach the maximum possible value.

Known injection laser (see patent RU No. 2230410, IPC H01S 5/042, published 10.06.2004), which includes a laser heterostructure with waveguide layers, in one of the bounding layers which are embossed patterns, at least part of metabolome and passive region with bases near the border of the bounding layer closest to the active region. At least part of the base of each passive region is embossed structure adjacent to metabolise having in the direction of pace dicumarol the longitudinal axis of the resonator, a length exceeding the distance, providing the scattering of radiation propagating in said direction perpendicular to the longitudinal axis of the resonator. Each relief structure has an amplitude of not less than 0.1 μm and distant from the aforementioned boundaries restrictive layer at a distance of not more than 0.5 micron.

Known laser has an increased power output radiation, narrowed and improved spatial diagram of the output radiation in the plane of p-n junction to a single-mode, improved emission spectrum to a single and stable parameters in view of increasing the efficiency of absorption of unwanted modes of high order and ring, optimization of the magnitude of the lateral optical limitations.

However, the known injection laser does not solve the problem of increasing optical power as the laser heterostructures with low internal optical losses are characterized by close to 100% localization of the field of laser modes in the waveguide layers. In this case, any periodic structure formed in any restrictive layers, become ineffective, because the laser fashion does not overlap with them.

Known injection laser (see No. 2230411, IPC H01S 5/034 published 10.06.2004), which includes a heterostructure containing active layer, at least the waveguide layers, granitelike layers, located on two sides of him, and metabolome grabdevice waveguide, formed by p-type heterostructures, with the base located in a restrictive layer, placed on the same side of the active layer. Restrictive layer from the p-type heterostructures formed of at least two sublayers having the same composition. Bounding the first sub-layer adjacent to the waveguide layer, or not doped, or has a concentration of p-type no more than 3·1017cm-3. Bordering the first subsequent restrictive sublayer has a concentration of p-type more than 3·1017cm-3metapolicy grabdevice waveguide formed bunk. The first tier coaxially located on the additionally introduced restrictive in the first sublayer of the second tier of metabolome having a width greater than the width of the first tier of metabolome 1.5-4 times.

In the known laser was reduced series resistance of the laser with minimal profile spreading and stabilization of a single-mode generation mode.

The disadvantage of this laser is the presence of optical communication with the lateral areas on metabolome. No additional technical solutions that increase the internal optical loss in the lateral areas, leads to the execution threshold services is the generation of closed modes and reduction in the output optical power.

The closest in technical essence and essential features is the injection laser (see patent RU No. 2259620, IPC H01S 5/32 published 27.08.2005). Injection laser prototype contains a hetero separate restrictions, including multimode waveguide, restrictive layers which are simultaneously emitter p - type and n-type conductivity with the same refractive indices, the active region comprising at least one quantum-well active layer, the location in which the waveguide and the thickness of the waveguide satisfy the relationship

G0QW/GmQW>1,7;

where G0QWand GmQWfactors optical constraints for the active region of zero fashion and fashion m (m=1, 2, 3...), respectively. Injection laser also includes reflectors, optical faces, ohmic contacts and the optical resonator. Active area placed in the additional layer, the refractive index greater than the refractive index of the waveguide, and the thickness and location in the waveguide is determined from the condition of execution of the said ratio, and distance from the active region to the p - and n-emitters do not exceed the diffusion length of holes and electrons in the waveguide, respectively.

Known injection laser has a small divergence from the teachings while maintaining high efficiency and output power of radiation.

The disadvantage of this laser is the presence of optical communication with the lateral areas on metabolome. The absence in the injection laser prototype additional technical solutions that increase the internal optical loss in the lateral areas, leads to the execution of the threshold conditions, the generation of closed modes and reduction in the output optical power.

The objective of the proposed technical solution was the development of this design injection laser, which would increase the output optical power both in continuous and pulsed modes of current pumping, increase the temporal stability of the output power.

The problem is solved in that the injection laser based on heterostructure includes a first waveguide layer enclosed between wide-gap emitter p - type and n-type conductivity, which is also restrictive layers, the active region comprising at least one quantum-well active layer, an optical Fabry-Perot resonator and the strip ohmic contact, which is the area of injection. At least in the first waveguide layer outside the area of injection is performed at least one alloy region. Factor optical limitations of a closed-loop fashion (ZM) in the alloy region and the oxygen is radio free charge carriers in the doped region satisfy the relation:

;

where- value component factor optical limit GYin gain for ZM, Rel. units;

- loss on the output of the Fabry-Perot fashion, cm-1;

αi- internal optical loss in the absorption of free charge carriers in the field gain, cm-1;

Δα is the optical loss due to scattering of radiation ZM on heterogeneities (αSC), interband absorption (αBGLand absorption of free charge carriers in the lateral parts of the injection laser relative to the strip ohmic contact, cm-1;

factor optical limitations of the SM in the alloyed region, Rel. units;

σn- the absorption cross section for a free electron in the alloyed region, cm2;

n is the concentration of free electrons in the alloy region, cm-3;

σp- the absorption cross section on the free holes in the alloy region, cm2;

p is the concentration of free holes in the alloy region, cm-3.

The distance between the nearest border alloy region and the injection may be not less than 10 μm, and its width is not less than 10 μm.

Alloy region may contain as a dopant of n-type conductivity element, you the early from the group of Si, Those, Ge, Sn, or a combination of both.

Alloy region may contain as a dopant of p-type conductivity element selected from the group of: C, S, Mg, Be, Zn, or a combination of both.

Alloy region can be formed by ion bombardment.

Alloy region can be formed by diffusion of an impurity from the surface layers in the waveguide layer.

At least in the first waveguide layer outside the area of injection can be performed two doped region located in the lateral parts of the injection laser.

The concentration of each dopant type may not be less than 1017cm-3.

Injection laser can include a second waveguide layer with a bandgap smaller bandgap width of the first waveguide layer, the active region is located in the second waveguide layer.

In the injection laser longitudinal size of the alloyed region may be less than the length of an optical Fabry-Perot resonator.

Heterostructure injection laser can be performed in the system of solid solutions And3B5.

Improvement of the output characteristics of the inventive injection laser is achieved by suppressing the generation of the SM.

The inventive injection laser is illustrated in the drawing, where

1 shows a known injects the traditional laser with a strip ohmic contact;

figure 2 shows the inventive injection laser, the side of which entered alloy region;

figure 3 shows the inventive injection laser with the first and second waveguide layers.

figure 4 shows the qualitative dependence of the material gain in the active line (curve 1) and the losses in the passive region (curve 2) as a function of wavelength (λFPand λCM- wavelength generation, respectively MTF and ZM,and- material gain, respectively, of the MTF and ZM,and- loss on interband absorption in the passive regions respectively for MTF and ZM);

figure 5 shows the dependence of the output power coming through the line-reflection-coated, from the pump current for a known injection laser and claimed injection laser (curve 3 - in continuous pump current, curve 4 - by pulsed pump current for a known laser; curve 5. - with continuous pump current, curve 6 - pulse when the pump current for the injection laser claimed).

Known injection laser (see figure 1) contains the first waveguide layer 1, concluded between wide-gap emitter 2 p-type conductivity and wide-gap emitter 3 of n-type conductivity, an active region 4, asteasu is from, at least one quantum-well active layer, an optical Fabry-Perot resonator formed naturally cleaved facet 5-reflection-coated and face 6 coated with a reflective coating, the strip ohmic contact 7, which is the injection region 8, which includes the area gain (shaded oblique solid lines) 9, side naturally cleaved facets forming the lateral bounding surfaces 10, the substrate 11, the sides of the injection laser (dashed slanted dashed lines) 12.

The proposed injection laser (see figure 2) contains the first waveguide layer 1, concluded between wide-gap emitter 2 p-type conductivity and wide-gap emitter 3 of n-type conductivity, an active region 4, consisting of at least one quantum-well active layer, an optical Fabry-Perot resonator formed naturally cleaved facet 5-reflection-coated and face 6 coated with a reflective coating, the strip ohmic contact 7, which is the injection region 8, which includes the area gain (shaded oblique solid lines) 9, side estestvenno.hotya faces forming lateral bounding surfaces 10, the substrate 11, the sides of the injection laser (shaded in the sloping dashed lines) 12, alloy region (shaded straight vertical lines) 13. Injection laser can contain two doped region 13 located in the lateral parts of the injection laser. The distance between the nearest border alloy region 13 and region 8 of the injection may be not less than 10 μm, and its width is not less than 10 μm. Alloy region 13 can contain as a dopant of n-type conductivity element selected from the group of Si, Te, Ge, Sn, or a combination of both. In another embodiment of the invention alloy region 13 can contain as a dopant of p-type conductivity element selected from the group of: C, S, Mg, Be, Zn, or a combination of both. Alloy region 13 may be formed, for example, by ion bombardment or by diffusion of an impurity from the surface layers in the first waveguide layer 1. The concentration of each dopant type may not be less than 1017cm-3. Injection laser can include a second waveguide layer 14 (see figure 3) with a bandgap smaller bandgap width of the first waveguide layer 1, the active region 4 is located in the second waveguide layer 14. The longitudinal size of the alloyed region 13 may be less than the length of an optical Fabry-Perot resonator. Heterostructure injection laser can be performed in the solid system is solutions And 3B5.

Improvement of the output characteristics of the inventive injection laser is achieved by suppressing the generation of the SM. For injection lasers characteristic mode radiation pattern, which is calculated using the wave equation [Hkeyi, Manish. - Laser heterostructures. - Moscow, Mir, 1981; L.A.Coldren, S.W.Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]. We can distinguish two types of modal structures. The first is fashion Fabry-Perot resonator (MTF). For these modes is characterized by the propagation of radiation along the optical axis of the resonator at an angle to the normal relative to the mirrors of the Fabry-Perot resonator (naturally cleaved facets 5-reflection-coated faces and 6 coated with a reflective coating) smaller than the angle of total internal reflection. As a result, the MTF characteristic different from zero losses in the output radiation from the resonator. It is this radiation is useful when using injection lasers as optical sources. Patterns of fashion Fabry-Perot resonator determine the waveguides formed by the first waveguide and the emitter (restrictive) layers (1, 2, 3) heterostructures, strip ohmic contact 7 and mirrors (5, 6) Fabry-Perot resonator. The second type of modal structures is ZM. For these modes is characterized by the spread of radiation under the Glami to relatively normal mirrors (5, 6) Fabry-Perot resonator and the lateral bounding surfaces 10 greater than the angle of total internal reflection. As a result, ZM characteristic zero loss at the output radiation from the resonator. Patterns ZM define the waveguides, waveguide formed and the emitter (restrictive) layers of the heterostructure, the strip ohmic contact, mirrors, Fabry-Perot resonator and the lateral bounding surfaces. Performing threshold generation conditions for the MTF or ZM determines the mode of operation of the injection laser. When the threshold is made only for MTF, the maximum useful output efficiency and, accordingly, the output optical power is growing. When performing threshold generation conditions for the SM part of the laser radiation do not come out and remains inside the injection laser, as a consequence there is a partial or full drop of the output power and lower efficiency. In the injection laser the lasing threshold of the laser modes is achieved when the following two conditions: equality modal gain total optical losses and feedback. The first condition is satisfied by the injection current flowing through the strip ohmic contact 7 and generates the inverse population of charge carriers in the active region 4 strip under the economic contact 7. Thus, in the active region 4 under the strip ohmic contact 7 has created the conditions for the amplification of optical radiation, and this part of the active region 4 is called region 9 gain. For the lateral parts of the active region 4 relative to the strip ohmic contact 7 conditions for amplification are not created because they are electrically isolated from the injection current. However, it remains optical connection between the side parts of the active region 4 and region 9 gain through a common first waveguide layer 1. The second condition for injection lasers is due to the resonator, formed naturally cleaved facets. Naturally cleaved faces form two types of cavities: cavity Fabry-Perot formed by two mirrors 5, 6 is parallel to the cleaved facets of the resonator ZM formed four cleaved facets (faces - mirrors 5, 6 and orthogonal to them faces - lateral bounding surfaces 10), limiting the injection laser and resulting in the manufacture of injection laser by splitting the heterostructure. In General, the threshold condition for lasing can be written as [L.A.Coldren, S.W.Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]:

where Gmodmodal gain, created injected into the active region 4 of the charge carriers, αi- NR the internal optical loss in region 9 gain and α out- losses associated with the output laser radiation from the resonator. The modal gain is expressed through material gain (gmat)calculated through concentration injected in the active region 4 of the charge carriers [L.A.Coldren, S.W.Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)], and the factor optical limitations fashion (G) in region 9 gain:

In General form factor optical constraints on the gain determines the amount of energy of laser fashion, attributable to this area, and is expressed through the electric field of fashion injection laser E(x, y, z) [L.A.Coldren, S.W.Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]

where Vg is the volume of area 9 gain, Vm is the volume of the injection laser. The field of fashion is described in works [L.A.Coldren, S.W.Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]

Factor optical limiting fashion in region 9 strengthening the injection laser is expressed through three independent components factor optical limiting fashion in region 9 gain GX, GYand GZ(see figure 1).

In the injection laser with a strip ohmic contact 7, the width of the strip ohmic contact (w) is greater than the length of wave generation and mirrors (5, 6) Fabre the Pen resonator limits the gain in the direction parallel to the axis of the resonator. This field allows the MTF to be fully localized in the area bounded by the dimensions of the strip ohmic contact and the length of the resonator. Means for MTF GY=1 and GZ=1. Electromagnetic wave MTF extend along the axis of the Fabry-Perot resonator at angles less than the angle of total internal reection with respect to the normal to the mirrors (5, 6) Fabry-Perot resonator, and is characterized by loss of output radiation from the resonator αout. Component factor optical limit GXsame for SM and MTF and depends on the design of laser heterostructures: the composition and thickness of the first waveguide and restrictive layers (1, 2, 3)and the thickness of the active region 4. For laser heterostructures GXis a factor of the optical industry transverse waveguide in the active region 4 GQW. Then the threshold condition generation (1) for the MTF can be rewritten as

wherematerial gain at the wavelength of the generation of the MTF;

- loss on the output of the MTF;

αi- internal optical loss due to absorption by free charge carriers.

To determine the threshold condition generation for SM, it is necessary to evaluate the conditions of its distribution in the injection the laser. Unlike PGP, electromagnetic waves ZM extend at angles greater than the angle of total internal reflection, relative to the normal to the lateral bounding surfaces 10 and mirrors (5, 6) Fabry-Perot resonator. For ZM characteristic zero loss at the output radiation from the resonator. In [Chaliponga, Daidokoro, Avelocity, Naidin, Allantic, Navratilova, Adendorf, Istratov. - FTP, 43, 1409 (2009)] it was shown experimentally that in contrast to PGP, ZM captures the entire volume of the injection laser, including the side of the contact strip 7. Figure 4 shows the qualitative dependence on the wavelength of the material gain in area 9 of the reinforcement strip under the ohmic contact 7 (gmatand from the optical losses (αBGLin the lateral regions relative to the strip ohmic contact. MTF with a maximum value of material gainat the generation wavelength λFPcorresponds to a high enough value losses on interband absorption in the passive regions. As a consequence, the distribution area of the MTF is limited only by the area under the strip ohmic contact. From figure 4 it is seen that the offset in the long-wave region of the spectrum relative to the wavelength of the generation of the MTF at the same time leads to the decrease of material which CSOs gain in the active region 4 and the falling value of optical loss (α BGLin the lateral regions relative to the strip ohmic contact 7. Thus, because of the zero loss output for SM even under smaller values of material gainat the generation wavelength for SM can be made the generation threshold. Consider the threshold condition generation for ZM in the injection laser with a strip ohmic contact 7. As ZM captures all of the first waveguide layer 1 injection laser, the factor optical limitations ZM for strengthening (GCM) looks as follows

where- value component factor optical limit GYin region 9 gain for the SM. As shown above (and confirmed experimentally), the length λCMwave generation SM is shifted into the low-energy region of the spectrum relative to the MTF. Material gain ZM () can be represented as:

where Δ is the detuning of material gain, defined as the difference between the material gains of the MTF and ZM. Optical loss for SM αCMcan be expressed as:

the value of Δα take into account the losses associated with scattering of radiation ZM on heterogeneities, mezzo the major absorption and absorption by free charge carriers in the lateral parts of the injection laser relative to the strip ohmic contact 7. Since the optical loss at the output radiation for ZM is equal to zero, the expression (9) they are ignored.

Based on the above threshold conditions for SM will take the form:

Taking the value Δ=0 taking into account (3) we obtain the inequality, the satisfaction of which suppresses the generation of SM in known injection lasers

Created at least in the first waveguide layer 1 outside the scope of 8 injection of at least one alloy region 13 can increase optical loss for SM on the value of. The increase in loss for SM to values at which executes the specified inequality allows to suppress the generation of SM in the inventive injection laser. Required to suppress the generation of the SM value of the internal optical loss in the generated alloy region 13 is selected by selecting its size and position, solving the wave equation that determines the value ofand by selecting the concentration and type of dopant.

The inventive injection laser operates in the following manner. Through the strip ohmic contact 7 of the inventive injection laser (see figure 2) in the direction perpendicular to the layers of the heterostructure, electric current is passed, and the mode of operation of the injection hole is a (laser diode) corresponds to the direct displacement of the p-n junction. When excess current flows through the injection laser, the threshold through the naturally cleaved facet mirror 5-reflection-coated - enters the laser Fabry-Perot fashion. The power of the emergent radiation, in addition to the parameters of a structure depends on the value passed through the laser heterostructure current. Spontaneous emission on-line generation of a closed-loop fashion is absorbed in the alloy region 13 (see figure 2). This suppresses feedback for closed loop fashion. The result is stored generation only mod Fabry-Perot resonator, which leads to maintaining the linearity of the dependence of the output power from the pump current and increase the output optical power.

Example. Comparative tests of known injection laser and injection laser claimed. Was made known injection laser based on a heterostructure that includes a waveguide layer of GaAs with a thickness of 0.6 μm wide gap existing between the emitter of the Al0.3Ga0.7As p-type conductivity with a thickness of 1.5 μm and wide-gap emitter Al0.3Ga0.7As n-type conductivity with a thickness of 1.5 μm, an active region consisting of a single quantum-well active layer In0.26GA0.74As the thickness of 8.5 nm, optical Fabry-Perot resonator 1.5 mm long, formed naturally cleaved what ranu-reflection-coated, having a reflectance of 5%, and a face coated with a reflective coating having a reflectivity of 95%, the strip ohmic contact width of 100 μm, situated in the centre between the lateral naturally cleaved facets, the distance between which is 500 μm, a GaAs substrate n-type conductivity. For a known injection laser of the value of the internal optical losses and losses on the exit of the radiation modes of Fabry-Perot resonator was 2 cm-1and 10.15 cm-1, respectively. Through contact strip known injection laser (see figure 1) in the direction perpendicular to the layers of the heterostructure, an electrical current was passed, and the mode injection laser corresponds to the direct displacement of the p-n junction. In the first variant of the pumping missed a continuous current, and the second pumping missed pulse current with a current pulse duration of 100 NS and a frequency of 10 kHz. For a known injection laser dependence of the optical power coming through the line-reflection-coated, continuous current pumping is shown in figure 5 (curve 3), the pulse current of the pump shown in figure 5 (curve 4). Maximum value of the optical output power was achieved with continuous pump current 5.4 W at pulse current pumping of 34.5 watts.

The inventive injection laser differed about the known injection laser, however, what in the waveguide layer was formed alloy region. The doping was carried out by zinc, an impurity of p-type conductivity, and the concentration of p=1018cm-3with the absorption cross section on the free holes in the alloy region σp=7*10-18cm2. Closest to the area of injection border alloy region located at a distance of 100 μm. The width of the region doping was 100 μm, the factor of the optical limitations of the SM in the alloyed region=0.2, the value of the component factor optical limit GYin gain for the ZM=0.2. When the selected area parameters alloying inequality

running. Through the strip ohmic contact and the proposed injection laser (see figure 2) in the direction perpendicular to the layers of the heterostructure, an electrical current was passed, and the mode injection laser corresponded to the direct displacement of the p-n junction. In the first variant of the pumping missed a continuous current, and the second pumping missed pulse current with a current pulse duration of 100 NS and a frequency of 10 kHz. For the injection laser claimed the dependence of the optical power coming through the line-reflection-coated, continuous current pump is provided in figure 5 (curve 5), for the pulse current of the pump shown in figure 5 (curve 6). Maximum value of the optical output power was achieved with continuous pump current of 8.8 watts, pulse current pumping of 54.5 watts. The output optical power obtained for the injection laser, was higher than in the known injection laser. Measurement of the output power over time showed that the temporal stability of the signal injection laser claimed higher than in the known injection laser. Thus, the claimed injection laser has an increased optical output power in continuous wave and pulse mode, and also has enhanced long-term stability of the output power.

1. Injection laser based on a heterostructure that includes a first waveguide layer enclosed between wide-gap emitter p - type and n-type conductivity, which is also restrictive layers, the active region comprising at least one quantum-well active layer, an optical Fabry-Perot resonator and the strip ohmic contact, which is the area of injection, characterized in that, at least in the first waveguide layer outside the area of injection is performed at least one alloy region, and the factor optical limitations will lock the OI fashion (SM) alloy region and the concentration of free charge carriers in the doped region satisfy the relation

where- value component factor optical limit GYin gain for ZM, Rel. units;
- loss on the output of the Fabry-Perot fashion, cm-1;
αi- internal optical loss in the absorption of free charge carriers in the field gain, cm-1;
Δα is the optical loss due to scattering of radiation ZM on heterogeneities (αSC), interband absorption (αBGLand absorption of free charge carriers in the lateral parts of the injection laser relative to the strip ohmic contact, cm-1;
factor optical limitations of the SM in the alloyed region, Rel. units;
σn- the absorption cross section for a free electron in the alloyed region, cm2;
n is the concentration of free electrons in the alloy region, cm-3;
σp- the absorption cross section on the free holes in the alloy region, cm2;
p is the concentration of free holes in the alloy region, cm-3.

2. Injection laser according to claim 1, characterized in that the distance between the nearest border alloy region and the injection of not less than 10 μm.

3. Injection laser according to claim 1, characterized in that the width of the alloy area of not less than 10 μm.

4. Injects the traditional laser according to claim 1, characterized in that the alloy region contains as a dopant of n-type conductivity element selected from the group of Si, Te, Ge, Sn, or a combination of both.

5. Injection laser according to claim 4, characterized in that the concentration of the dopant of n-type conductivity is not less than 1018cm-3.

6. Injection laser according to claim 1, characterized in that the alloy region contains as a dopant of p-type conductivity element selected from the group of: C, S, Mg, Be, Zn, or a combination of both.

7. Injection laser according to claim 6, characterized in that the concentration of the dopant of p-type conductivity is not less than 1017cm-3.

8. Injection laser according to claim 1, characterized in that the alloy region is formed by ion bombardment.

9. Injection laser according to claim 1, characterized in that the alloy region is formed by diffusion of impurities from the surface layers in the waveguide layer.

10. Injection laser according to claim 1, characterized in that, at least in the first waveguide layer outside the area of injection performed two doped region located in the lateral parts of the injection laser.

11. Injection laser according to claim 1, characterized in that it contains the second waveguide layer with a bandgap smaller bandgap width of the first waveguide layer and an active region located in the second waveguide layer.

12. Injection laser according to claim 1, characterized in that the longitudinal size of the alloyed region is less than the length of the optical Fabry-Perot resonator.

13. Injection laser according to claim 1, wherein the heterostructure is made in the system of solid solutions And3B5.



 

Same patents:

Injection laser // 2443044

FIELD: optics.

SUBSTANCE: heterostructure based laser contains waveguide layer placed between wide-gap emitters of p and n-conductivity type that are simultaneously the limiting layers, active zone consisting of quantum-dimensional active layer, optical Fabry-Perot cavity and stripe ohmic contact under which the injection zone is located. In the waveguide layer outside the injection area there is the introduction of the area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area. The factor of optical confinement of closed mode of abovementioned semiconductor material fits the ratio: where: - values of the compounds of optical confinement factor G for closed mode in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, relative units; αNB - optical losses related to interband absorption of closed mode radiation in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, cm-1.

EFFECT: increase of output optic power in both continuous and pulse current injection mode, as well as increased time stability of output active power.

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EFFECT: possibility to output radiation, which is wideband by wave length, in vertical direction.

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SUBSTANCE: diode multi-beam source of coherent laser radiation comprises a master laser, integrally and optically connected to a linear amplifier, two perpendicular amplifiers, integrally and optically connected to the linear amplifier. The master laser and said amplifiers are in form of a single heterostructure. The heterostructure comprises an active layer and two limiting layers and a radiation influx area having an influx layer. The heterostructure is characterised by the ratio of the refractive index nef of the heterostructure to the refractive index nvt of the influx layer. The ratio of nef to nvt is determined from a range extending from one to one minus gamma, where gamma are defined by a number much less than one. The linear amplifier is positioned so that the optical axis of radiation propagation from the master laser coincides with the axis of the linear amplifier. Each perpendicular amplifier has an output edge and is positioned so that its optical axis is at a right angle to the axis of the linear amplifier. There is an element near the crossing point of amplifier axes in order to facilitate flow of a portion of radiation from the linear amplifier to a perpendicular amplifier. This element includes a reflecting plane which intersects the active layer and part of the influx area of the heterostructure within 20% to 80% of the thickness of the influx layer and which forms a 45° angle of inclination with amplifier axes.

EFFECT: high power of laser radiation, high efficiency, reliability, longer operating life and modulation rate with simplification of the manufacturing technique.

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SUBSTANCE: laser has a semi-insulating substrate, a quantum-sized active region of intrinsic conduction which forms second-type heterojunctions with top and bottom waveguide layers, and also having a horizontal mutual arrangement of emitters of the first and second type conduction. The top waveguide layer forms a first type heterojunction with a second type conduction top optical limiting top region, and the bottom waveguide layer forms a first type heterojunction with a second type conduction bottom optical limiting region. The laser has a first type conduction control region the top of which adjoins the substrate and the bottom to the bottom second type conduction optical limiting region and forms a p-n junction with it, an ohmic contact to the first type conduction control region, a control metal contact whose top adjoins the second type conduction top optical limiting region and forms a Schottky junction with it. Ohmic contacts to the regions of emitters of first and second conduction types are on the top face of a semiconductor crystal. The lower border of the conduction zone of the active region coincides with the lower border of the conduction zone of the top waveguide layer. The upper border of the valence band of the active region coincides with the upper border of the valence zone of the bottom waveguide layer.

EFFECT: faster operation of the device.

3 dwg

FIELD: physics.

SUBSTANCE: diode multi-beam source of coherent laser radiation has at least one laser diode and at least two diode optical amplifiers integrally connected to the said laser and formed in the same heterostructure. The heterostructure has at least one active layer and two bounding layers and a radiation-transparent influx region having an influx layer. The heterostructure is characterised by ratio of refraction index nef of the heterostructure to the refraction index nin of the influx layer. The ratio of nef to nin is defined in the range from one plus delta to one minus gamma, where delta and gamma are defined by a number much less than one and gamma is greater than delta. In connection area of each active amplification region of amplifiers to the active region of laser generation there is an integrated spillover element of the given part of laser radiation from the laser to the amplifier. The said element includes at least two laser radiation reflecting optical planes which are perpendicular to the plane of the layers of the heterostructure and penetrate with crossing of the active layer inside the influx layer by a depth selected from the range between 20% and 80% of the thickness of the influx layer. The reflecting plane is turned approximately 45° (modulus) about the optical axes of the laser and amplifier.

EFFECT: high output power of amplified laser radiation, high efficiency, reliability, longer service life and modulation rate with simplification of the technology of manufacturing the source.

14 cl, 8 dwg

FIELD: electricity.

SUBSTANCE: tunnel-coupled semi-conducting heterostructure includes substrate (1) GaAs of n-type conductivity, to which there subsequently applied is buffer layer (2) GaAs of n-type conductivity, at least two laser diode structures (3) separated with tunnel junction (4), and contact layer (5) GaAs of p+-type conductivity. Each laser diode structure (3) includes the first wide-band gap emitter layer (6) AlGaAs of n-type conductivity, wide wave-guide (7) GaAs in the centre of which there located is narrow-band gap quantum-well active area (8) InGaAs and the second wide-band gap emitter layer (9) AlGaAs of p+-type conductivity. Tunnel junction (4) includes layer (10) GaAs of p+-type conductivity, unalloyed quantum-well solid layer (11) GaAs 40-50 angstrem thick and layer (12) GaAs of n-type conductivity.

EFFECT: increasing the capacity of manufactured instrument and its service life.

4 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: laser diode matrix includes the base made from heat-conducting material with heat-conducting dielectric material and laser diode rules located on the base, which consist of laser diodes, current-leading contact pads and dustproof cover. Matrix is made of separate rules of laser diodes. Each rule of laser diodes includes negative terminal and positive terminal, its own heat sink. Negative terminal of each previous rule of laser diodes is connected to positive terminal of the next rule of laser diodes. Terminals of end rules of laser diodes are connected to current-leading contact pads. Installation method of rules of laser diodes is carried out by bonding the heat sink of laser diodes rules to heat-conducting dielectric material, after which an electric connection of negative terminal of each previous rule of laser diodes with positive terminal of the next rule of laser diodes is performed by unsoldering; then, electric connection of terminals of end rules of laser diodes with current-leading contact pads is performed by unsoldering.

EFFECT: improving operating reliability of laser diode matrix.

2 cl, 2 dwg, 1 ex

FIELD: physics.

SUBSTANCE: diode laser includes a heterostructure which contains at least one active layer, at least two limiting layers, a radiation influx region which is transparent to the radiation which has at least an influx layer. The heterostructure is characterised by ratio of refraction index nef of the heterostructure to the refraction index nin of the influx layer. The ratio of nef to nin is defined in the range from one plus delta to on minus gamma, where delta and gamma are defined by a number much less than one and gamma is greater than delta. At a certain distance from both lateral sides of the active region with flowing current, there are radiation limiting regions, penetrating from the outer layer inside the heterostructure to at least the active layer. Thickeness of the layers of the heterostructure lies in the interval from (λ/4nef) mcm to (4λ/nef) mcm, where λ is the laser radiation wavelength. The integrated diode laser is a combination of integrally connected diode lasers placed along the optical axis of propagation of the laser radiation. The integrated semiconductor optical amplifier includes integrally connected master diode laser and a semiconductor amplifier element. Integral connection in the devices is achieved through the radiation influx region.

EFFECT: lower density of threshold generation currents, improved stability of mode generation, increased power of the laser radiation and strength of blind reflectors of the resonator.

16 cl, 8 dwg

FIELD: physics.

SUBSTANCE: method of assembling laser diode structures (active elements) on a heat-removing base made from boron nitride ceramic involves depositing onto the surface of the heat-removing base a series of metal layers of at least a metal-coating layer and a solder layer, putting the active element onto the metal layer, aligning it relative the base, soldering it while heating in a reducing medium with or without a mechanical load on the element and its subsequent cooling. According to the invention, the first metal-coating layer with thickness of 0.1-0.2 mcm is chemically deposited onto the surface of the heat-removing base by depositing nickel metal from a cured electrolyte with the following ratio of components, in wt %: NiCl2·6H2O - 45-55; NaH2PO2·H2O - 9-13; (NH4)·HC6H5O7 - 60-70; NH4Cl - 45-55. The SnPb (or In) solder layer is deposited through vacuum coating and thickness of the solder layer is selected depending on the size of the laser structures.

EFFECT: simpler assembling process and assembling reproducibility, increased reliability and quality of the contact joint, improved temperature-compensation parametres, and possibility of replacing precious metals used in assembling laser structures on heat sinks.

1 ex

FIELD: electric engineering.

SUBSTANCE: invention relates to quantum electronics, namely, to semi-conductor lasers. The said laser contains hetero structure of divided limitation including multimode waveguide with limiting layers being implemented as p- and n-type conductivity emitters with similar refraction indices. The laser also includes active zone, reflectors, optical edges, ohmic contacts and optical resonator. The active zone forms volumetric layer of semi-conducting material. The width of band gap in this layer is less than the band gap width of waveguide. The thickness of volumetric active zone dar meets inequation , where - planks constant, mh,e - electron hole mass, λ - length of generation wave in vacuum. E - kinetic energy of charge carriers, which is taken the least between calculated mh and me.

EFFECT: increased peak laser radiation at reduced width of laser diode spectrum in impulse generation mode.

1 dwg

Injection laser // 2443044

FIELD: optics.

SUBSTANCE: heterostructure based laser contains waveguide layer placed between wide-gap emitters of p and n-conductivity type that are simultaneously the limiting layers, active zone consisting of quantum-dimensional active layer, optical Fabry-Perot cavity and stripe ohmic contact under which the injection zone is located. In the waveguide layer outside the injection area there is the introduction of the area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area. The factor of optical confinement of closed mode of abovementioned semiconductor material fits the ratio: where: - values of the compounds of optical confinement factor G for closed mode in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, relative units; αNB - optical losses related to interband absorption of closed mode radiation in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, cm-1.

EFFECT: increase of output optic power in both continuous and pulse current injection mode, as well as increased time stability of output active power.

13 cl, 4 dwg

Semiconductor laser // 2408119

FIELD: physics.

SUBSTANCE: semiconductor laser has a heterostructure in form of a thin plane-parallel plate, two mirrors which form an optical resonator having an optical axis and lying on both sides of the heterostructure, and pumping apparatus. Using the pumping apparatus, a volume is excited in the heterostructure, having a dimension along the axis of the resonator which is considerably smaller than across the axis of the resonator. The optical resonator has at least one extra absorbing layer in which nonequilibrium-carrier recombination takes place. The extra absorbing layer lies perpendicular the optical axis in the resonator mode unit, whose wavelength lies on the maximum of the spectrum of optical amplification of the heterostructure. Said absorbing layer absorbs spontaneous radiation propagating at an angle to the optical axis outside the fundamental mode of the resonator.

EFFECT: increase in power of the laser owing increase in cross dimensions of the excitation region.

32 cl, 1 dwg

Injection laser // 2443044

FIELD: optics.

SUBSTANCE: heterostructure based laser contains waveguide layer placed between wide-gap emitters of p and n-conductivity type that are simultaneously the limiting layers, active zone consisting of quantum-dimensional active layer, optical Fabry-Perot cavity and stripe ohmic contact under which the injection zone is located. In the waveguide layer outside the injection area there is the introduction of the area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area. The factor of optical confinement of closed mode of abovementioned semiconductor material fits the ratio: where: - values of the compounds of optical confinement factor G for closed mode in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, relative units; αNB - optical losses related to interband absorption of closed mode radiation in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, cm-1.

EFFECT: increase of output optic power in both continuous and pulse current injection mode, as well as increased time stability of output active power.

13 cl, 4 dwg

FIELD: physics.

SUBSTANCE: laser electron beam device includes an electron gun, electron beam focusing and deflecting systems and a laser screen. The screen includes a plane-parallel semiconductor plate with reflecting coatings on its surface. The device also includes a microwave deflecting system between the electron gun and the deflecting system, and a slot mask made from electron-absorbing material placed on the laser screen on the side of the electron beam. The semiconductor plate is made from semiconductor materials with different wavelength of the generated radiation in regions lying on different sides of an arbitrary bridge of the slot mask.

EFFECT: possibility of generating synchronised picosecond laser pulses at two wavelengths with possibility of scanning the laser radiation within limits determined by the size of the laser screen.

1 dwg

FIELD: physics.

SUBSTANCE: semiconductor laser emitter includes a laser crystal with positive and negative electrical leads and an electrical input unit with a coplanar microwave transmission strip line formed on a dielectric substrate. The laser crystal is connected to earthing leads of the coplanar microwave transmission strip line by negative leads, and by the other lead to the signal track of the same coplanar microwave transmission strip line. In the laser crystal, the positive and negative leads are made on one side with leads of one polarity lying between loads of the other polarity. The laser crystal is installed via "reverse mounting" and is soldered to the end the coplanar microwave transmission strip line formed on the dielectric substrate. The coplanar microwave transmission strip line lies under the laser crystal so as to match corresponding leads of the laser crystal and the signal and earthing strips of the coplanar microwave transmission strip line.

EFFECT: wider modulation band.

7 dwg

FIELD: physics.

SUBSTANCE: proposed laser comprises high-voltage pulse generator, transfer line, chamber with electrodes and solid state laser target. Said target consists of plane-parallel solid state plate and dielectric substrate with one or several orifices. Dielectric substrate and solid state plate are interconnected via dielectric interlayer used to rule out breakdown in air gap between surfaces of aforesaid plate and substrate. Substrate dielectric constant is smaller than that of solid state plate. One electrode of said laser is arranged on the side of solid state plate, while the other one can move on the side on dielectric substrate and has one or several orifices aligned with those in substrate.

EFFECT: stabilised generation zone and chances to generate simultaneously in several zones of solid state plate.

6 cl, 2 dwg

The invention relates to a laser device with nitride semiconductor

The invention relates to an efficient high-power semiconductor injection lasers and laser diode bars

FIELD: physics.

SUBSTANCE: proposed laser comprises high-voltage pulse generator, transfer line, chamber with electrodes and solid state laser target. Said target consists of plane-parallel solid state plate and dielectric substrate with one or several orifices. Dielectric substrate and solid state plate are interconnected via dielectric interlayer used to rule out breakdown in air gap between surfaces of aforesaid plate and substrate. Substrate dielectric constant is smaller than that of solid state plate. One electrode of said laser is arranged on the side of solid state plate, while the other one can move on the side on dielectric substrate and has one or several orifices aligned with those in substrate.

EFFECT: stabilised generation zone and chances to generate simultaneously in several zones of solid state plate.

6 cl, 2 dwg

FIELD: physics.

SUBSTANCE: semiconductor laser emitter includes a laser crystal with positive and negative electrical leads and an electrical input unit with a coplanar microwave transmission strip line formed on a dielectric substrate. The laser crystal is connected to earthing leads of the coplanar microwave transmission strip line by negative leads, and by the other lead to the signal track of the same coplanar microwave transmission strip line. In the laser crystal, the positive and negative leads are made on one side with leads of one polarity lying between loads of the other polarity. The laser crystal is installed via "reverse mounting" and is soldered to the end the coplanar microwave transmission strip line formed on the dielectric substrate. The coplanar microwave transmission strip line lies under the laser crystal so as to match corresponding leads of the laser crystal and the signal and earthing strips of the coplanar microwave transmission strip line.

EFFECT: wider modulation band.

7 dwg

FIELD: physics.

SUBSTANCE: laser electron beam device includes an electron gun, electron beam focusing and deflecting systems and a laser screen. The screen includes a plane-parallel semiconductor plate with reflecting coatings on its surface. The device also includes a microwave deflecting system between the electron gun and the deflecting system, and a slot mask made from electron-absorbing material placed on the laser screen on the side of the electron beam. The semiconductor plate is made from semiconductor materials with different wavelength of the generated radiation in regions lying on different sides of an arbitrary bridge of the slot mask.

EFFECT: possibility of generating synchronised picosecond laser pulses at two wavelengths with possibility of scanning the laser radiation within limits determined by the size of the laser screen.

1 dwg

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