An optical 90/spl deg/-hybrid balanced receiver module using a planar lightwave circuit

An optical 90/spl deg/-hybrid coherent receiver module is constructed that uses the planar lightwave circuit technique. The module consists of an optical 90/spl deg/-hybrid silica planar waveguide and two 14 GHz balanced O/E converters; the solder-bump technique is employed. For both sets of paths between the optical coupler and the twin-p-i-n photodetector pairs, the effective propagation time differences were reduced to within 4 ps. A 10 Gb/s BPSK homodyne detection experiment confirms the feasibility of the receiver.>