High power 1.55 /spl mu/m DPB laser diodes integrated with vertical mode expanders

Summary form only given. In conclusion, we have fabricated a 1.55 /spl mu/m strained InGaAsP semiconductor DFB QW laser diode with a narrow divergence beam profile by monolithically integrating a vertical mode expander inside the laser cavity. Over 80mW single mode output power was obtained with the side mode suppression ratio greater than 40dB. The coupling loss of a tapered DFB LD into a lensed single mode fiber was about 2.2dB (corresponding to 60% coupling efficiency) due to circular nature of the output beam.