Chirp Modulated CO2 Laser Radar Oscillator

The objective of this program was to investigate intracavity electrooptical phase modulation of a CO2 waveguide laser with the aim of constructing a frequency-chirped master oscillator for application in a 10 micrometer imaging radar. During this six-month program a special phase sampling technique for frequency locking of the modulated master oscillator to an unmodulated reference laser was investigated. An important experimental result was the measurement of the relative phase between the two lasers by this sampling technique. The development of the UARL waveguide lasers was continued resulting in a sealed-off, reliable laboratory device of 0.3 W output power and a lifetime of about 1,000 hrs yielding repetitive linear chirps of 75 MHz width and 2 microsec duration.