Spatial beating in twin-waveguide diode lasers

Summary form only given.Semiconductor lasers are usually designed so that only the fundamental transverse mode of the multilayered structure is above cutoff. Some exceptions are twin-waveguide (TG) lasers, which can be designed to lase on either one or both transverse modes and broad-waveguide (BW) lasers, which are designed to lase on the fundamental transverse mode but can lase on two transverse modes. Another laser type that utilizes a TG structure is the antiguided array laser fabricated with a modulated cap, thin p-clad structure. Because the design of such lasers is complicated due to the existence of two or more transverse modes, it is of interest to develop diagnostic techniques which allow one to obtain information about the nature of these modes. In this paper we report on a novel TG laser designed such that one can observe the spatial beat pattern generated by the two transverse modes in the TG structure.