The far field of PbSnTe injection lasers

The far-field pattern perpendicular to the junction plane of a PbSnTe injection laser with controlled carrier concentration was measured. The far-field pattern, calculated according to the Lewin formalism and represented by the obliquity factor (Oron and Zussman, 1980), is shown to differ only by about 2 percent from the alternative expressions of Lewin (1975) and Butler and Zoroofchi (1974). The experimental far-field pattern are shown to agree with the theoretical calculations with a deviation of less than 10 percent. The TE and TM far-field patterns are discussed, and design considerations are given for constructing laser structures having an improved far-field pattern.