Abstract

Frequency tuned IR laser sources can be achieved by generating the upper and the lower sidebands from a CO₂ laser using an electrooptic phase modulator. The phase modulator, which is driven by a microwave TWT amplifier in the X and Ku bands (8 to 18 GHz) can be made of either a GaAs IR waveguide with a traveling-wave microstrip transmission line (Ref. 1) or a bulk CdTe crystal filled microwave cavity operating in a resonant mode (Ref. 2). The difference between the two approaches is primarily in the achievable frequency tuning range. With a microstrip IR waveguide modulator, the frequency tuning range of 20 GHz, which is at least 20 times wider than that obtainable with a bulk crystal filled microwave cavity can be achieved. The sideband powers of comparable magnitudes (~ 2mW) can be generated by using either of the above two techniques.

© 1990 Optical Society of America