43Gb/s balanced photoreceiver using monolithic integrated lensed facet waveguide dual-UTC photodiodes

By integrating a monolithic lens using dry etching of the input mirror facet of an UTC photodiode, we have achieved > 4-fold improvement of alignment tolerance in the lateral axis without compromising diode efficiency. Lensed photodiodes show simultaneously 0.76 A/W with low polarisation loss (0.3 dB).