Abstract

We present a surface emitting GaAs/AlGaAs laser diode beam steering device using the surface mode emission (SME) technique [1], The SME laser diode is based on a conventional GaAs/AlGaAs double-heterostructure grown by MOCVD. The crucial difference to a conventional laser diode is a surface-relief grating (period I., grating vector k_g=2π/L) covered with a semitransparent AuZnAu-film and a photoresist layer forming a surface waveguide. This structure supports a TE₀-mode which can be excited by the laser light propagating in the active region via one grating vector according to k_laser-k_e=k_TE0. The TE₀-mode propagates in the surface-waveguide and emits via one grating vector into air with a well-defined angle α =arcsin(n_eff-2λ/L) where n_eff is the effective refractive index of the laser diode and λ the emission wavelength. The TE₀-mode in turn emits back into the active region providing a wavelength selective feedback resulting in a single-mode operation.

© 1998 IEEE