Output fluctuations of CW-pumped Nd:YAG lasers

The mechanisms that cause amplitude modulation in CW-pumped YAG lasers were investigated experimentally. The depth of modulation and frequency spectrum of the output fluctuations of a commercially available Nd:YAG laser were measured. It was found that after performing several modifications on the laser system, the output fluctuations were reduced by two orders of magnitude. At the conclusion of the program, the depth of modulation for frequencies below 10 Hz was 10^-2, and for frequencies between 10 Hz and 100 kHz, it was 10^-3. Above 100 kHz, the modulation decreased rapidly to 10^-5reaching shot noise level above 500 kHz.