An in-cavity Q-regulating photo-electric switching device used for same beam multi-pulse laser, same-beam multi-pulse multi-wavelength laser, pollution measuring radar, dual-wavelength homography, spectrofluorescence diagnosis, satellite range finding, etc is composed of polarizer, Q-regulating crystal, polarized splitter and electric control system of Q-regulating crystal. Under the control of said control system, the Q-regulating crystal can respectively generate 1/4-wave, O-wave and 1/2-wave voltages, whose time sequence and waveforms can be controlled to obtain the transmission characteristics of particularly combined beam in directions A and B. |