Monolithically integrated DBR lasers with simple tapered waveguide for low-loss fibre coupling

The Letter describes InGaAsP/InP 1.55 μm distributed Bragg reflector lasers monolithically integrated with a laterally tapered waveguide on the output facet. The tapered waveguide region of the devices has a thick partially clad p-InP layer grown by selective growth. The growth and fabrication processing steps were the same as those used to make conventional DBR laser diodes. The lasers demonstrate good lasing characteristics, lowloss coupling of less than 2.8 dB and +/− 2 μm misalignment tolerance with a flat-end singlemode fibre in both the lateral and vertical directions.