Phase II year
1994 (last award dollars: 1994)
CO2 range-doppler lidars can accomplish a part of SDIO's mission of finding ballistic missiles in flight by utilizing an output format compatible with extracting precision range (short pulse) and precision doppler (long pulse, low chirp) information from the target. One way to accomplish this mission would be to combine an energetic short pulse format with a long low chirp pulse format by using a sealed-off laser transmitter which has an intracavity modulator and an excitation approach which is compatible with very high level pulsed and gated CW pumping. Until now, these discharge pumping characteristics were not available from a single CO2 laser. With RF/dc excitation, very high level discharge pumping can be achieved by applying a short high peak power RF pulse to a pair of transverse electrodes; this in turn causes an energy storage capacitor to discharge into the pulsed RF discharge with a level of pumping that was shown in the Phase I program to be several times the CW level for 1 microsecond. At similar pressures, the same device was pumped with gated CW excitation with only an RF source. The Phase I program also showed this type of pumping could be combined with an intracavity modulator to generate pulses with peak powers over 1000 times the CW output level. The Phase II program will advance this work to design, deliver and test a fully programmable CW, gated CW or multipulse format lidar transmitter.