Abstract: A photo-semiconductor module includes a laser diode for emitting a laser beam, a lens and a photo-detector arranged in a casing so as to be optically coupled to each other. The laser beam, emitted from the laser diode, travels through the lens and exits the casing, and the photo-detector detects at least a part of the laser beam and outputs a detection signal used for controlling the laser diode. The laser diode and the lens are mounted on a first structure and thermally coupled thereto and the first structure is mounted on and thermally coupled to a cooling-element, thereby to cool the laser diode by conducting heat coupled therefrom and through the first structure to the cooling element. The photo-detector is mounted on a second structure which is thermally isolated from the cooling-element.

Abstract: An optical module in which light emitted from a light emitting element fixed to a substrate is made incident on an optical fiber through an optical lens, including a lens holder which immovably supports the optical lens, and a lens holder guide fixed to the substrate to support the lens holder. The invention is also directed to a method of manufacturing an optical module including moving the holder guide and the lens holder on the substrate and in the lens holder guide, in orthogonal x-y directions and in a z-direction perpendicular to the x-y directions, respectively, to adjust the position of the lens, so that the light emitted from the light emitting element is incident on the optical fiber, and then fixing the lens holder guide and the lens holder to the substrate and the lens holder guide, respectively.