Temperature-stable pumping realization through the optimization the pump-laser spectral distribution in optical amplifiers

A new approach to stabilizing the temperature of laser diode arrays for pumping is proposed and experimentally demonstrated. Experimental results show that when the pump center wavelengths of the two optical amplifiers are set to 804.0 nm and 810.5 nm, stable pumping laser operation over a temperature range exceeding 15 °C can be achieved. The concept of the effective, rather than actual, absorption spectrum is introduced for the first time, in order to better analyze the laser diode pump spectral characteristics of the Nd:YAG material of the optical amplifier. The effective absorption spectrum for a typical LD spectrum shape is evaluated, and experiments demonstrate that the fluctuation of the center wavelength of the pump affects the pumping energy distribution. A proof-of-concept 1064 nm laser system is especially developed, demonstrating the generation of 3.36J laser pulses of pulsewidth 4.58 ns and beam quality 2.12 times of diffraction limit, at a frequency of 100 Hz.