Control of the repetition rate and reduction of the jitter of the pulses of passively Q-switched solid-state miniature lasers using periodic diode-pump modulation

Based on an extended point laser model, the lasing of passively Q-switched Nd : YAG minilasers has been numerically analysed. We have shown that periodically modulated diode pump may be used to control the pulse repetition rate and substantially reduce the timing pulse jitter. When the pump is modulated with rectangular pulses, switching from a high pump level to a low one upon generation of a successive laser pulse improves the stability of the pulse repetition rate relative to variations of the average pump level and broadens the range of repetition frequencies whereby they may be locked to the pulse modulation frequency. The feasibility of lowering the timing jitter and locking the pulse repetition frequency to the pump modulation frequency has been confirmed experimentally. For repetition rates ~1 kHz, the relative standard deviation of the pulse-repetition period is reduced from several percent for a continuous pumping to 0.06 % by applying "truncation" of modulation pulses. The experimental results agree well with simulations.