Depending on the particulars of an engagement scenario, doppler shifts due to the relative motion of a missile and a sensor platform can be in excess of 1000 MHz for a coherent COE2 sensor system. Since the response of the sensor's heterodyne detector can be degraded by as much as 50% at these large offset frequencies, a local oscillator capable of being tuned either up or down 1000 MHz to compensate for this relative motion would be equivalent to increasing the sensor's laser transmitter power by a factor of two. Because a coherent COE2 sensor system already has a LO, any improvement in system performance afforded by an improved LO would be accomplished without altering the system weight, size or power budget. Two separate innovations, one in resonator design and another in discharge excitation are proposed to achieve a Phase I goal of 100 mW of sealed-off cw laser output power at 1500 MHz from laser line center.
