Patent ID: 7628547

Claim:
An optical module comprising: a light source; a variable transmissivity member that is disposed in a light path of light emitted from the light source with a spacing of a first distance from the light source, the variable transmissivity member having transmissivity that increases as temperature rises; a partial reflection member that is disposed on the light path of the light emitted from the light source with a spacing of a second distance from the light source, the second distance being larger than the first distance, the partial reflection member reflecting a first light component and transmitting a second light component of light that has been transmitted through the variable transmissivity member; a light quantity monitor that is disposed in a light path of the first light component; and an optical fiber that receives the second light component, the variable transmissivity member being disposed so as that the light path of the light emitted and the light path of the first light component pass through, and the light quantity monitor detecting quantity of the first light component, wherein a first temperature inclination representing transmissivity variation with respect to temperature variation in the partial reflection member is smaller than a second temperature inclination representing transmissivity variation with respect to temperature variation in the variable transmissivity member.