Compact Radio Frequency Discharge-Pumped Slab CO Laser System with a Zinc Germanium Phosphide (ZnGeP2) Sum-Frequency Generator for Remote Sensing of the Atmosphere

Based on our experimental study of spectral characteristics of an improved compact CO laser system, the prospects of using such a laser system for solving urgent problems of atmospheric sounding were demonstrated. An increase in the number of laser lines due to intracavity generation of the second harmonic and sum-frequencies in a nonlinear zinc germanium phosphide (ZnGeP₂) crystal enriches capabilities of the laser. It was shown that such a CO laser system with frequency conversion in ZnGeP₂ crystal can be used for detection and measuring concentration of at least 14 minor natural and pollution gases components of the atmosphere. The advantages and disadvantages of various laser operation modes, and the prospects for using its radiation for atmospheric remote sensing in various spectral ranges are discussed.

Frequency conversion of mid-IR lasers into the long-wavelength domain of 12-20 µm with AgGaSe2, BaGa2GeSe6 and PbIn6Te10 nonlinear crystals

Difference frequency generation under mixing of repetitively-pulsed CO- and CO₂-laser radiation in AgGaSe₂, BaGa₂GeSe₆ and PbIn₆Te₁₀ nonlinear crystals was studied. Efficiency and refractive indices were examined for this frequency conversion into the long-wave domain of ∼12-20 µm in the mid-IR. The highest frequency conversion efficiency of 10^-4 was obtained for a relatively new PbIn₆Te₁₀ crystal, which is an order of magnitude higher than previous results.

Sum frequency generation of multi-line slab radio frequency discharge carbon monoxide laser system with intracavity nonlinear BaGa2GeSe6 crystal

A compact repetitively pulsed broadband carbon monoxide (CO) laser system with intracavity frequency conversion, for which a nonlinear crystal was also used as an output coupler, was launched for the first time, to the best of our knowledge. The laser system simultaneously operated in two spectral ranges: CO laser fundamental band (4.9-6.0 μm) and its sum frequencies band (2.45-2.95 μm). Different designs of the laser cavity were considered. Peak powers of the fundamental and sum frequencies laser pulses were up to 2 kW and 10 W, respectively.