Patent ID: 8049159

Claim:
An optical transmitter-receiver subassembly comprising: a light-emitting element which converts a current into an output optical signal; a light-receiving element which converts an input optical signal from an optical fiber into a current; a planar lightwave circuit which guides the output optical signal and the input optical signal, and comprises the light-emitting element and the light-receiving element; a first land pad through which the current to be input to the light-emitting element passes; a second land pad through which the current output from the light-receiving element passes; a package which is electrically coupled to the planar lightwave circuit, said first land pad and said second land pad being on an external surface of said package; and a thermally conductive grand pad on the external surface of said package and electrically connected to said planar lightwave circuit, the grand pad radiating heat from the planar lightwave circuit to an exterior.