Compact bidirectional optical module using ceramic blocks

A new compact 1.3/1.55-μm bidirectional optical module with an integrated wavelength-division-multiplexing (WDM) subassembly has been developed using accurate ceramic blocks. The WDM subassembly on which a laser diode, a receiver photodiode, a WDM filter, and two microlenses are integrated is only 2.0 × 2.1 × 0.6 mm 3 in size and assembled in a TO-CAN package. The AlN ceramic blocks are used to reduce the variation of the component displacements. The transmitted output power of -8.1 dBm at pigtail with the coupling efficiency of 16 % and the received sensitivity of 0.95 A/W are obtained. With this design, the process and the time for packaging bidirectional optical modules can be dramatically reduced.