Laser gain module small-signal gain increase due to suppression of parasitic generation with pump geometry optimization

Abstract

A method for optical pump scheme optimization for a laser gain module with pulsed diode arrays for Nd:YAG rods (Ø10 × 130 mm & Ø10 × 160 mm) is presented. The goal is to maximize the small-signal gain of the laser gain module while maintaining a flat-top amplification profile. A possible way of the overall small-signal gain reduction due to amplified spontaneous emission is discussed and a method to deal with this phenomenon is given. As a result of optical pump scheme optimization, the gain module with the maximum pump power of 40 kW for 250 µs pulse duration at repetition rates of up to 25 Hz is created. The maximum small-signal gain G = 100 at 1.064 µm is achieved.