Longitudinal and radiation modes in GaAs single-heterojunction distributed-feedback injection lasers

We report experiments with single-heterojunction (SH) distributed-feedback (DFB) GaAs diode lasers. Narrow-linewidth (< 0.15 Å), single-mode operation has been observed. Highly collimated beams of 0.6 × 10^-2rad divergence radiated perpendicular to the p-n junction have also been produced. These beams are virtually 100 percent polarized with the E-vector parallel to the corrugation grating.