High repetition rate, high peak power, pulsed single-longitudinal-mode Nd:YAG laser by self-injection-seeding

A self-injection-seeding technique is numerically simulated and analyzed for the first time and a self-injection-seeded laser is realized. The numerical results show that the counter-propagating beams traveling in a ring resonator reach their maximum diffraction efficiency at different incident angles in an acousto-optic modulator (AOM). At the incident angle deviated from the Bragg angle by θM the maximum diffraction efficiency between the two counter-propagating waves occurs, the θM becomes smaller with the increasing sound frequency, while it is independent of the sound power. The maximum difference scales with the sound power and the sound frequency. The peak laser power almost increases linearly with the sound power and the maximum repetition rate increases linearly with the pump power. At an average power of 1 W, an output of repetition rate of 2 kHz and pulse width of 475 ns representing a peak power of 1.1 kW is experimentally demonstrated, which is the best result reported for self-injection-seeding. The beam intensity profile is close to a Gaussian distribution and the beam quality factor M2 is 1.3.