Abstract: This optical module includes a cable including an optical fiber, and a connector module. The connector module includes: a circuit board having a first surface and a second surface; a metal housing in which the circuit board is disposed and which includes a plate-shaped portion facing the second surface; a resin housing in which the metal housing is disposed; and a heat transfer member which is disposed on the second surface. The plate-shaped portion of the metal housing includes a first region overlapping with the heat transfer member in plan view, and a second region located around the first region. The first region is closer to the second surface than the second region, and is in contact with the heat transfer member. A heat insulating region is disposed between the first region and the resin housing.

Abstract: A method of forming a through hole, wherein a spot of a laser light scans along a predetermined path and forms a through hole includes a first process in which the spot of the laser light circulates along an inner path from a predetermined first point on the inner path and reaches a predetermined second point. The inner path is positioned at an inner side relative to an outer path. The predetermined second point is positioned before the spot of the laser light returns to the predetermined first point. The method includes a second process in which the spot of the laser light moves along a transition path and reaches a predetermined third point on the outer path. The method includes a third process in which the spot of the laser light circulates along the outer path from the predetermined third point and returns to the predetermined third point.