Abstract: A differential signal transmission cable includes a pair of differential signal lines arranged in parallel to each other, an insulation for bundle-covering the pair of differential signal lines, and a shield conductor wound around an outer periphery of the insulation. The insulation is configured such that an outer circumference thereof in a cross section perpendicular to a longitudinal direction thereof has an oval shape formed with a continuous convex arc-curve. The oval shape has a width in a first direction along the arrangement direction of the pair of differential signal lines being larger than a width in a second direction orthogonal to the first direction.

Abstract: A multi-channel optical receiver module, includes a light-receiving element array, the light-receiving element array including multiple light-receiving elements; an amplifier disposed adjacent the light-receiving element array, the amplifier amplifying an output of a light-receiving element; a wiring relay submount disposed adjacent the amplifier; two wires for carrying a differential signal and being wired in parallel to one another and being connected between the wiring relay submount and the amplifier; an output pin; and another wire, the another wire being connected between the output pin and the wiring relay submount.