15 W Single Frequency Optically Pumped Semiconductor Laser With Sub-Megahertz Linewidth

We report on a single frequency optically pumped semiconductor laser exhibiting an output power of 15 W in continuous wave operation. The GaAs-based structure presents an emission wavelength of 1020 nm and a tuning range , with a continuous tunability of 9 GHz. The TEM
₀₀
output beam exhibits very low transverse phase fluctuations across the entire mode, leading to a beam quality . A free-running laser linewidth of 21 kHz has been deduced from frequency noise measurements for a sampling time of 1 ms and increases to 995 kHz for a sampling time of 1 s.