Mid-infrared parameter oscillator

Abstract

The invention relates to a mid-infrared parameter oscillator, belonging to the technical field of laser. The invention comprises a 1.06mu m laser and a two-level optical parameter oscillator and a light focusing cavity; a laser resonant cavity of the 1.06mu m laser and a first level optical parameter oscillator use a same resonant cavity mirror, the first level optical parameter oscillator and a second level optical parameter oscillator use a same resonant cavity mirror. The two-level optical parameter oscillator of the invention is an inner cavity type non-critical phase matching optical parameter oscillator and the optical parameter conversion receiving angle is large, a walk-off angle is small. The invention can fully use optical power density in a pump optical cavity and optical parameter conversion polarization matched condition to derivate various structures, reduce the technical requirement on pump light of optical parameter oscillator, therefore, the optical parameter conversion efficiency is high and high power mid-infrared laser can be obtained; the structure of the laser is simpler, volume is small, cost is low and overall cost performance is high.

Description

technical field [0001] The invention relates to a mid-infrared optical parametric oscillator, which belongs to the field of laser technology, and specifically relates to the cavity design of the optical parametric oscillator in solid-state laser technology, which is suitable for military use and trace gas detection such as photoelectric countermeasures, biochemical threat detection, and imaging laser radar. Such as: natural gas pipeline leak detection, methane detection in coal mines and other civil fields. Background technique [0002] The optical parametric oscillator is a device that generates mid-infrared laser. It converts near-infrared Nd:YAG 1.06μm laser into 1.5-5μm laser by using frequency down-conversion technology. The optical parametric oscillator is composed of a pump laser, a nonlinear crystal, and an oscillator optical resonator. Under the action of a strong pump light field, the signal light and idler light generated in the nonlinear crystal are gradually est...

AI Technical Summary

Problems solved by technology

It can be seen from the above that it is difficult to obtain high-power mid-infrared lasers by directly pumping the KTA optical parametric oscillator at 1.06 μm

[0005] 3. The US patent "monolithic serial optical parametric oscillator" (Patent No. US6344920B1) uses a 1.06μm laser to pump the first-stage non-critical phase-matched KTA optical parametric oscillator to generate a 1.53μm eye-safe laser, and then uses a 1.53μm eye-safe laser Pump the second-stage non-critical phase-matched KTA optical parametric oscillator to achieve 2.59μm signal light and 3.76μm idler light output. This method reduces the quantum number deficit between the signal light and the idler light by increasing the wavelength of the pump light. Small, thus improving the conversion efficiency of mid-infrared idler light, but the first-stage optical parametric oscillator in the patent is an external cavity type. In order to increase the power density of the 1.06μm pump light, it is often necessary to use an optical system to compress the pump light spot. Instead, the divergence angle of the pump light is increased. According to the characteristics of the optical parametric oscillator, the divergence angle of the parametric light of the first-stage and second-stage optical parametric oscillators will increase. Finally, in order to compress the divergence angle of the parametric light, the magnification of the compression telescope will be The increase will greatly increase the complexity and volume of the entire laser, and also increase the difficulty of debugging the laser. In addition, the remaining 1.06μm pump light may be fed back into the 1.06μm laser to affect its performance. In order to prevent this from happening, often Adding an optical isolator between the 1.06μm laser and the optical parametric oscillator will undoubtedly increase the complexity and volume of the entire laser, and adding components will also increase the cost of the laser

Images