Patent ID: 9036675
Filing Date: 2015-05-19
Classification: H01S,H04B

Abstract:
1. A communication module comprising: a substrate; a laser element provided on a front surface of the substrate; a light receiving element provided on the front surface of the substrate and separated from the laser element; a transparent resin package collectively sealing the laser element and the light receiving element, the resin package including a package body sealing and adhering to the laser element and the light receiving element, and having a front package surface disposed upward of the laser element and parallel to the front surface of the substrate; and a diffusion unit provided to be opposed to a light emitting surface of the laser element at a prescribed distance for diffusing a laser beam emitted by the laser element, the light receiving element being disposed in a region that is not directly underneath the diffusion unit, the diffusion unit including a diffuser, which is separate and differs from the package body, having a diffusion surface and a non-diffusion surface on a side opposite to the diffusion surface, the diffuser being directly adhered to said front package surface disposed upward of the laser element in a posture directing the diffusion surface upward so that the diffusion surface faces upward, wherein a distance T between the laser element and the light receiving element satisfies a following formula (1): further wherein in the formula (1), t θ represents a maximum angle of emission of the laser element, t θ′ represents a maximum diffusion angle of the diffusion unit.