Thermally induced birefringence compensation in double-pulse Q-switched laser

Double-pulse laser experimental results of generating approximately 100 ns temporal delay between the pulses with polarization beam combining by two sets of flashlamp pumped electrooptical Q-switched laser is reported for the first time. The interval of co-aligned double-pulse laser can be turned freely from 0 to several hundred nanoseconds. The maximal relative timing jitter of double-pulse laser is less than 5 ns. The laser beam control is another difficult issue in developing double pulse laser. Two 1/4 lambda waveplates are inserted in the double pulse laser, and the thermal induced birefringence can be effectively compensated, and the Q-switched laser pulse energy can be increased by 26 percent. The repetition rate of double-pulse laser is 40 Hz, and output energy per double-pulse is more than 400 mJ.