Wavelength tuning and intensity noise in diode laser butt coupling

摘要

Abstract: Coherent optical feedback into a continuously operating diode laser causes optical output power fluctuations as well as a spectrum shift. This spectrum shift can be accounted for by solving the boundary value problem for the optical field. We choose another method, in which the change of the nonlinear laser characteristics and the optical properties of the oscillation cavity versus the effective reflectance of Fabry-Perot etalon formed by the laser output mirror and an external reflector is described by a phenomenological model. We consider a high power laser diode with significant external feedback from the entrance facet of a butt-coupled fiber and explain the wavelength variations of up to 15 nm versus laser-to-fiber separation that we observed experimentally. The longitudinal mode spectrum of the butt- coupled laser diode is characterized as well. !9