Characterization of a Low-phase-noise, High-power (370 mW), External- Cavity Semiconductor Laser

摘要

Past research efforts have attempted to demonstrate semiconductor lasers with reduced levels of phase noise, approaching noise levels typically observed in highly coherent solid state lasers. In this work, detailed phase noise measurements have been performed on an expanded-mode, external cavity semiconductor laser with a longer cavity length and much higher output power than similar commercial lasers. These results demonstrate that the high frequency phase noise due to spontaneous emission was reduced significantly relative to existing COTS semiconductor lasers. The measured phase noise for this novel external cavity semiconductor laser was within a factor of two of commercially available fiber lasers, and within a factor of 20 of a Nd:YAG laser, over the 1 Hz to 10 MHz frequency range.