Optical transceiver having heat-dissipating path from assembly substrate directly to upper housing

An optical transceiver that is to be plugged into a cage of a host system, comprising:

• a multi-fiber push-on (MPO) connector that receives an external optical connector;
• an assembly substrate having a primary surface, the assembly substrate mounting a holder and at least a semiconductor optical device on the primary surface thereof, the semiconductor optical device having an optical axis substantially in perpendicular to the primary surface of the assembly substrate;
• a lens block mounted on the primary surface of the assembly substrate, the lens block bending the optical axis of the semiconductor optical device toward a direction substantially in parallel to the primary surface of the assembly substrate;
• a circuit board that mounts electronic circuits electrically coupled with the semiconductor optical device;
• at least an inner fiber that couples the lens block with the MPO connector;
• and
• a housing including a top housing and a bottom housing that form an inner space enclosing the MPO connector, the assembly substrate, the lens block, the circuit board, and the inner fiber therein,
• wherein the bottom housing mounts the circuit board thereon and the top housing is thermally and physically in contact to the assembly substrate,
• wherein the optical transceiver provides a plurality of the inner fibers in an arrayed form,
• wherein the assembly substrate mounts a plurality of the semiconductor optical devices,
• wherein the lens block provides a plurality of lens elements coupled with the respective semiconductor optical devices,
• wherein the arrayed fiber provides a first mechanically transferable (MT) ferrule in an end thereof, and a second MT ferrule in another end thereof, the first MT ferrule coupling with the MPO connector, the second MT ferrule coupling with the lens block, and
• wherein the holder surrounds the lens block.