| 摘要 |
In a very high power, stable frequency TEA pulsed laser a conventional CW laser tube 30 is positioned in a resonant cavity 10 with the high power TEA laser 40. The high power output pulses are frequency locked to the CW laser by adjusting a mirror 20 to change the optical length of the resonant cavity in response to the frequency of a portion of the output signal from the CW laser. The mirror 20 is dithered at 1kHz with TEA laser off and the CW laser on. A 2kHz dither is superimposed on the output signal because of the output characteristic. At the peak of the characteristic only a fundamental 2kHz signal is present. This is detected by control circuits 80 which otherwise generate an error signal to reposition mirror 20. When the error vanishes the dither is switched off and the mirror 20 is held is place. Arrangement is used in target tracking where reflected laser beam is projected onto a detector together with a local laser beam to produce a heterodyne signal. Local laser frequency stabilisation is described. |
