Abstract

A distributed-feedback (DFB) laser emitting at 1.3-μm wavelength has been optimally designed to achieve stable single-mode operation well above threshold current. We fabricated DFB lasers with first-order corrugation in a newly developed buried heterostructure. One end of the laser cavity is as cleaved and the other end is low reflectivity coated. Optimum designing has been done on the structure taking account of phases of corrugation at facets and also the effect of spatial hole burning in the longitudinal direction caused by the nonuniform field distribution. The important result is that the spatial hole burning in the longitudinal direction drastically deteriorates the stable single-mode operation at the high optical output power level when the product of the coupling coefficient and the laser length is large. The configuration has been designed to minimize the nonuniformity of the optical field in the longitudinal direction. The optimally designed lasers exhibited a very low threshold total scattering. We discuss the effects of this on the autocorrelation function, as both the cluster size and scattering vectors are varied, the shape of the predicted values of the autocorrelation function is compared with experimental results.

© 1986 Optical Society of America