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Standoff methane detection set with He-Ne laser

The prototype of the dual He-Ne/He-Xe laser system for gas detection using differential absorption of radiation backscattered from topographic targets is described. Both lasers were excited by dc discharge and for lengths of 80 cm we obtained the output power of about 10 mW. Using receiver optics with the diameter of 7 cm and thermocooled HgCdTe detector we can measure the presence of methane on the distance up to 50 m. The new solution is under construction. to increase the range of measurement, the Casseigrain optics with diameter of 25 cm is being prepared. Using the special construction of RF excited gas lasers with the output power of 40 mW, the measurement distance of 100 m is expected.