Asymmetric output characteristics in 1.3-/spl mu/m spot-size converted laser diodes

A spot-size converted laser diode (SSC-LD) with a vertically tapered passive waveguide structure was fabricated by butt-joint-built-in (BJB) coupling and selective area metal organic chemical vapor deposition growth. A high coupling efficiency exceeding 50% and 1-dB alignment tolerance of /spl plusmn/2.5 /spl mu/m were obtained at a distance of 20 /spl mu/m between a flat-end single-mode fiber and the SSC-LD. Experimental results show that the asymmetric output property can be described by the radiation mode added to the guide mode and spatial hole-burning in the active region.