http://worldcat.org/entity/work/id/137616460

Frequency Agile Laser and Chemical Sensor

A compact, wavelength agile CO2 TEA laser and sensor have been developed for remote chemical detection. The laser is computer-controlled, sealed with an internal catalyst, and has a maximum firing and wavelength shift rate of 200 Hz with 40% duty cycle. The wavelength shifter operates in repeating patterns and can access any of 60 lines in any order. Multimode output energy exceeds 125 mJ for all lines and the pulse is composed of a 120 nsec wide spike, followed by a 1.5 microseconds tail that can be eliminated by an electro-optical modulator. Environmental testing was successful under a 3 G shock, 2 G sine wave vibration and a 0-40 deg C temperature range. An operational lifetime exceeding 50 million shots was demonstrated with tests terminated by the operator, not by malfunction. The fully integrated laser weighs 100 lb, occupies 3 cubic ft, and requires a source of 28 VDC to operate. The laser was integrated with a sensor and was successful in three separate field trials. Measurements of canvas target reflectivity over the spectral range 9.3-10.7 micrometers were within 15% of the calibrated values, normalized signal percentage standard deviation was 1-2% for a 16 pulse average, measurement of atmospheric water vapor was within the accuracy of meteorological instruments, and concentration-path length measurements with a vapor cell were in agreement with calibrated values.

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