A new packaging technique for an optical 90°-hybrid balanced receiver using planar lightwave circuits

A new packaging technique for an optical 90°-hybrid balanced receiver using planar lightwave circuits (PLC) has been developed for optical frequency division multiplexing (OFDM). This receiver consists of a silica-based PLC for an optical coupler and two polarization beam splitters (PBS), two GRIN rod lenses to achieve perfect optical interconnection, and two photoreceivers each having a preamplifier and twin PIN-PDs. The photoreceivers use the microsolder bump technique to eliminate the parasitic elements of the interconnections between the preamplifier and the twin PIN-PDs, and the impedance-matched film carrier technique to achieve impedance-matched interconnection between the preamplifier and the ceramic package. This receiver achieved a broadband frequency response of 14 GHz, and, consequently, 10-Gbit/s homodyne detection. The experiments showed that a receiver fabricated with our new packaging technique has excellent performance