DBR laser diodes emitting near 1064 nm with a narrow intrinsic linewidth of 2 kHz

Abstract

We report on the realization of distributed Bragg reflector laser diodes emitting near a wavelength of 1064 nm in a single longitudinal mode with high output power and kHz-level intrinsic spectral linewidth. Linewidth measurements are performed with a heterodyne measurement setup in which both lasers are weakly locked to each other in order to reject slow frequency drifts. The linewidth is analyzed in dependence of the output power. The FWHM linewidth is almost independent from the output power and corresponds to approximately 180 kHz whereas the intrinsic linewidth decreases with a 1/P out dependence. The minimum intrinsic linewidth is 2 kHz at an output power of 180 mW. The measured intrinsic linewidth is in good correspondence with a theoretical estimation.