Abstract

The interest to second order DFB semiconductor lasers is due to the difraction grating imbedded on the waveguide laser surface serving not only as a resonator, but also serving for the first order narrow-directed output of generated radiation, the latter being perpendicular or at a small angle to the active layer plane [1,2]. However, such radiation output not only improves the radiative device characteristics, but also helps to obtain direct experimental information about the physical processes in DFB lasers. A good example of this is the experimental discovery of a new type of distributed feedback in a multimode active waveguide – skip DFB generation – which is stipulated by grating coupling of radiation from a mode with one transverse number back into the mode with another transverse number[3].

© 1976 Optical Society of America