Pulsed solid-state two-frequency laser

 

The invention relates to a pulsed solid-state lasers with lasing at two wavelengths and can be used to obtain the powerful pulses of laser radiation in the near infrared range, including safe to the human eye. Pulsed solid-state laser includes two resonator with a total output mirror and one active element, the shutter on the effect of violations of total internal reflection (ATR). In the course reflected from the shutter the ATR beam are a polarizer, an electro-optical element and an end element of the resonator for wavelengthN. Along the direct beam are two deaf for wavelengthwith and transparent to radiation with lengthn mirrors. Provided high directivity of radiation. 1 Il.

The invention relates to a pulsed solid-state lasers operating in the mode of active q-switching with the possibility of lasing at two fixed wavelengths. The invention can be used for scientific purposes to pump the parametric generators, laser rangefinders the sights, providing far radiation.

The greatest practical interest is the generation of eye-safe radiation in the interval=1,53...of 1.55 μm with the possibility of generation and on the main lengthn=1,064 μm. The wavelength of the safe range is obtained as the first Stokes component of the radiation of 1.32 and 1.35 µm laser crystal YAG, GGG, and CPV.

Thus, the known laser [1] on the active element of the potassium-gadolinium tungstate (GFP), activated by ions of neodymium, generating in the safe range at wavelengthC=1,54 µm. The disadvantage of this laser is the complexity of manufacturing the selective resonator mirrors having a minimum reflectance for the fundamental wavelength, and the maximum reflectance for wavelengths=1,35 μm andC=1,54 µm, and the impossibility of generation at the fundamental wavelength with higher energy radiation.

Known pulsed solid-state laser [2] with the ability to generate both the main wavelengthn, and the signal wavelengthwith or simultaneous generation of containing sequentially rotator polarization plane, the active element, two swivel mirror installed between the positive focusing lens, return parametric mirror, a nonlinear element parametric light generator, the system of four mirrors for output emission of the main emission wavelengthN.

The disadvantage of this device is the design complexity (14 optical elements in the resonator), high radiation divergence due to the introduction into the cavity of a positive lens with a focal length of about 100 cm, and that the wavelengthC=1,571 μm beyond the eye-safe range.

The closest to the technical nature of the present device is selected as a prototype laser [3] trehseriynyy resonator formed by the output mirror and the two “blind” selective mirrors as of the end item, and the shutter on the effect of violations of total internal reflection (ATR). The disadvantage of this device is that known device has no way of generating the radiation wavelengthn major transition.

An object of the invention is to provide is to provide a high radiation pattern.

The problem is solved due to the fact that laser containing consistently located the output mirror, the active element, the shutter on the effect of violations of total internal reflection (ATR), two “deaf” for wavelengthwith and transparent to radiation with lengthn mirrors, added a polarizer, an electro-optical element and an end element of the resonator for wavelengthn, sequentially along the axis reflected from the shutter on the ATR beam radiation.

The drawing shows the optical scheme of the proposed device. The output mirror 1 and the “deaf” mirror 4, and the terminal element 7 is formed by two resonator configured to wavelengthsc andn, respectively. Between concavity elements is consistently active element 2, the shutter on the ATR 3, the polarizer 5 and the electro-optical element.

The operation of the device is as follows:

a) the mode of generation of radiation at a wavelength ofN.

In the active element 2 when the effect of pumping is generated by the primary radiation, which can spread VMware on the ATR 3 control voltage is the reflection of the beam of radiation on the boundary of the input prism and the air gap shutter on the ATR 3. After the radiation passes through the polarizer 5 and the electro-optical element 6. When applying to the electro-optic element 6 permanent locking quarter-wave voltage U/4polarization transmitted through laser radiation is changed by 45 degrees. Reflected from the end of item 7 (100% reflecting mirror, vintage mirror, and so on) and re-passing through the electro-optical element 6, the polarization of the radiation becomes orthogonal to the incident and is not passed by the polarizer 5. Thus, the resonator is locked and there is an accumulation of inversion in the active element. When applying after a certain time t on the electro-optical element 6 managing dynamic voltage plane of polarization at the output of the electro-optic element 6 becomes the source, the radiation passes through the polarizer 5, the shutter 3 and the active element 2. In the laser process development and generation of a giant pulse at a wavelength of major transitionN.

b) the mode of generation of radiation at a wavelength ofC.

When applying to the piezoelectric transducer shutter on the ATR control signal after a certain time t, it is omladine faces of the prisms of the gate is reduced, which leads to the absence of the reflected beam and the full transmission gate. Reflected from the two “deaf” mirrors 4 and re-passing through the shutter 3 and the active element 2 in the laser process development and generation of a giant pulse at wavelengthC.

The absence of radiation at wavelengthn during the time t, required for accumulation of inverted population in the active element is a permanent locking quarter-wave voltage U/4on the electro-optical element 6.

One of the key features of the proposed laser is that without a significant change of the optical circuit may be the generation of laser radiation with different wavelengths on the same active element without the use of parametric generation. In addition this device using neodimsoderzhashchikh environments as active medium allows you to work as a primary wavelength radiation with high efficiency, and in the eye-safe wavelength rangeC=1,53...1.55 um.

In a specific embodiment, the solid-state laser was used Akti is I the optimal mode of stabilization when working in the mode with frequency pulse repetition rate up to 20 Hz. As electro-optical elements are used, the lithium niobate crystal with beveled at the Brewster angle ends. The shutter on the ATR represented two transparent for radiation of a prism, the adjacent faces of which are formed plane-parallel gap thickness of several micrometer. On the truncated faces of the prisms were fixed piezoelectric transducers of the type P-3. The reflectance of the output mirror for wavelengthC=1.54 μ consistent with R=40%, for wavelengthn=1,067 µm R=20% and R=99,5% for=1,35 μm (transition4F3/2-4I13/2). The reflectance of each of the two selective mirror 4 R>99% for=1,35 μm and R<5% to=1,067 mm. When working in standalone mode as a leaf item 7 was used mirror with a reflectivity of R>99.5 per cent for wavelengthn=1,067 mm. When working in the frequency mode as an end item 7 was used prism-roof.

When the pump energy 5 j with lamp INP-35A, in the main lasing at wavelengthn=1,067 μm obtained energy gene>the sources of information

1. Ustimenko N. S., Gulin A. C. RF Patent №2115983 from 18.09.97.

2. Liashenko, A. I., p. C. L. Patent RF №2101817 from 13.05.96.

3. Wojciechowski C. N., Karpukhin S. N. // Optical magazine. - 1995. No. 11. - S. 30-35.

Claims

Pulse dual-frequency solid-state laser containing consistently located the output mirror, the active element, the shutter on the effect of violations of total internal reflection (ATR), two “deaf” for wavelengthwith and transparent to radiation with lengthn mirrors, characterized in that the laser is successively introduced in the course reflected from the shutter on the ATR beam of radiation, a polarizer, an electro-optical element and an end element of the resonator for wavelengthN.

 

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