Monolithic InP receiver chip with a 90° hybrid and 56 GHz balanced photodiodes.

We demonstrate a monolithically integrated quadrature coherent receiver photonic integrated circuit on an InP substrate with a 90° optical hybrid and two balanced 56 GHz pin-photodetectors on chip level and as a packaged device. The presented devices enable the use of 56/64 Gbaud dual polarisation 16-QAM signals either in the C-band or the L-band.