Wavelength-adjustable surface-emitting single-mode laser diodes with contradirectional surface-mode coupling

Single-mode surface emission has been achieved from visible red GaInP/AlGaInP laser diodes by applying the contradirectional surface-mode coupling technique. The emission wavelength (679.4 nm) of the laser structures was adjusted (decreased) in steps of 0.2 nm in an interval of 1.2 nm by reducing the thickness of the waveguide on top of the laser diode. The laser diodes emitted via the surface with a beam divergence of 0.12° and showed single-mode emission both in ac as well as in dc operation with a minimum spectral linewidth of 0.09 nm. The highest side-mode suppression achieved in dc operation was 26 dB.