Development of an injection-seeded single-frequency laser by using the phase modulated technique

An injection-seeded single-frequency Q-switched Nd:YAG laser is accomplished by using a phase modulated ramp-fire technique. A RbTiOPO₄ (RTP) electro-optic crystal is selected for effective optical path length modulation of the slave self-filtering unstable resonator. This single-frequency laser is capable of producing 50 mJ pulse energy at 1 Hz repetition rate with a pulse width of 16 ns. The standard deviation of laser pulse intensity for consecutive 100 shots from the mean pulse intensity is less than 1.05%. A spectral linewidth of less than 0.5 pm with a frequency jitter of about 14 fm over 30 min is obtained.