Optical transceiver

1. An optical transceiver insertable to an apparatus in a first direction, the optical transceiver comprising:

an optical port including first paired ports and second paired ports, the first paired ports and the second paired ports being arranged in line in a second direction perpendicular to the first direction;

paired transmitter optical sub-assemblies (TOSAs) each performing an electrical-to-optical signal conversion, one of the paired TOSAs being optically connected to one of the first paired ports through a first fiber, another of the paired TOSAs being optically connected to one of the second paired ports through a second fiber, the paired TOSAs being arranged to each other in line in the second direction;

paired receiver optical sub-assemblies (ROSAs) each performing an optical-to-electrical signal conversion, one of the paired ROSAs being optically connected to another of the first paired ports through a third fiber, another of the paired ROSAs being optically connected to another of the second paired ports through a fourth fiber, the paired ROSAs being arranged to each other in line in the second direction;

a printed circuit board (PCB) including an electrical circuit electrically connected to the paired TOSAs and the paired ROSAs; and

a housing configured to house the optical port, the paired ROSAs, the paired TOSAs, and the PCB, so that the paired ROSAs are arranged between the optical port and the PCB in the first direction and the paired TOSAs are arranged between the paired ROSAs and the PCB in the first direction.

2. An optical transceiver according to claim 1 , further comprising a relay board electrically connected to the paired ROSAs and the PCB.

3. An optical transceiver according to claim 1 ,

wherein the first fiber extends toward the optical port from a first sleeve of the one of the paired TOSAs in the first direction,

wherein the third fiber extends toward the PCB from a second sleeve of the one of the paired TOSAs in the first direction, and

wherein the second sleeve has a height from the PCB larger than a height of the first sleeve from the PCB.

4. An optical transceiver according to claim 2 , further comprising:

a first flexible printed circuit (FPC) electrically connecting the paired TOSAs and the PCB;

a second FPC including a first sub FPC and a second sub FPC, the first sub FPC electrically connecting the paired ROSAs to the relay board, the second sub FPC electrically connecting the relay board to the PCB.

5. An optical transceiver according to claim 1 , further comprising:

a holding member holding the one of the first paired ports, the one of the second paired ports, the another of the first paired ports, and the another of the second paired ports in this order in the second direction;

an elastic sheet having holes in which the first pared ports and the second paired ports fit respectively; and

a retainer plate pressing the first paired ports and the second paired ports against the elastic sheet.