Wavelength stabilization and spectra narrowing of a 405 nm external-cavity semiconductor laser based on a volume Bragg grating.

We introduce a 405 nm external-cavity semiconductor laser using a volume Bragg grating (VBG) as the feedback element. By decreasing the length of the external cavity and reducing the wavelength difference between the output wavelength of the laser diode during free running and Bragg wavelength of the VBG, the emission wavelength of the semiconductor laser is stably locked at 405.1 nm with a spectral linewidth of 0.08 nm. The output power reaches 292 mW, and the wavelength drift with temperature reduces to 0.0006 nm/°C. These results are helping for the spectroscopy applications of a blue-violet laser diode. In contrast to traditional external-cavity semiconductor lasers, this laser is less expensive and more compact, in addition to having a narrow linewidth and good wavelength stability. These advantages would facilitate the development of associated areas of research, including optical data storage, laser display, and laser medicine.