Beam Control in an Intracavity Frequency-Doubling Semiconductor Disk Laser

In this paper, we have demonstrated a 1.3 W green laser using a V-shaped intracavity frequency doubling 1036 nm semiconductor disk laser. The beam quality of the fundamental and second harmonic generation (SHG) laser is investigated. It has been found that the output lasers at the fundamental and SHG wavelength both suffer from reduced beam quality along with power scaling. The measured beam profile is elliptical under high power operation. In order to improve the SHG laser beam, an intracavity aperture is employed to control the mode characteristics of fundamental frequency light. By fine-tuning the aperture, a nearly circular beam profile with improving beam quality and brightness is realized