Simple numerical control loop for stabilizing Nd:YAG and Nd:YLF single-mode oscillators

A novel technique for longitudinal mode selection in Q-switched lasers

“…In paper [1] cavity length remained constant for two hours while maintaining coolant, crystal and air temperature constant with a high accuracy (±0.1 K), which is very inconvenient in practice. In papers [2][3][4][5][6] the principle of feedback was used to maintain optimum cavity length. In [2,3] it was shown that by measuring the difference of FPE reflectivity from pulse to pulse and by moving the mirror by a piezoceramic actuator, one can achieve stable single-mode generation in a slow (minutes) change in the cavity length.…”

“…This method requires reliable operation of high-speed electronics, and it is ineffective in lasers with high gain [7]. In [5,6] a pump with high pulse duration (6 ms) was used for single-mode generation, which is inconvenient and inefficient. The method with injection into the cavity implies continuous radiation of auxiliary diode-pumped laser [8][9][10][11], which leads to complication of the whole scheme.…”