High Receiver Responsivity And Low Dark Current Of Inp-Based Pin-Photodiode Array Monolithically Integrated With 90 Degrees Hybrid And Spot-Size Converter Using Selective Embedding Regrowth

The InP-based pin-photodiode array monolithically integrated with a 90 degrees hybrid and spot-size converters was realized using selective embedding regrowth for compact 100 Gb/s coherent receivers. The low dark current of less than 500 pA up to 85 degrees C was attained by InP passivation effect in four-channel pin-photodiodes. As a receiver using these photodiode arrays, a receiver responsivity including total loss of 6.7 dB in the 90 degrees hybrid and intrinsic loss of 3 dB in the polarization beam splitter was higher than 0.060A/W between -5 degrees C and 85 degrees C through the integration of the spot-size converter. Responsivity imbalance of the In-phase and Quadrature channels was also less than 0.5 dB over the C-band.