Wavelength stabilization of extended-cavity tapered lasers with volume Bragg gratings

The wavelength stabilization of high-brightness extended-cavity lasers at 810-nm by the use of volume Bragg gratings is described. Narrow linewidth (< 20 pm), high power (2.5 W) and good beam quality (M2<4) operation has been obtained in a robust and simple design. The impact of the beam focusing into the Bragg grating on the external cavity performance has been theoretically and experimentally investigated. Finally, second-harmonic generation of the infrared beam has been obtained in a ppKTP crystal, demonstrating a non-linear conversion efficiency of 0.8%/W and up to 8 mW at 405 nm

Tunable External Cavity Semiconductor Lasers.

In this study, we propose a new method to tune the semiconductor laser lasing frequency and reducing the laser linewidth using an external deriving field. We redeveloped Floquet S-matrix which determines the transmission probabilities and the shape and position of the induced quasibound state, which accumulated incident electrons. We explored the S-matrix numerically for various system parameters. We found that the oscillating field amplitude V1 plays a curial rule in defining the profile of electrons accumulations in the quasibound state and the field’s strength made sift the position of the quasibound state. This sift in the bound state energy due field’s strength is used to tune the lasing frequency and the output of the semiconductor laser linewidth is improved by changing the field’s amplitude the deriving field. By narrowing down the electron accumulations profile the laser linewidth would be narrower