Patent ID: 7103284

Claim:
A light-emitting module used in an optical communication system as an optical signal source, comprising: a primary assembly including a semiconductor light-emitting device for emitting light of predetermined wavelength at a temperature, a semiconductor light-receiving device for receiving light emitted from the light-emitting device, and a temperature-sensing device for monitoring the temperature of the light-emitting device; a thermoelectric element for controlling the temperature of the light-emitting device, the thermoelectric element mounting the primary assembly thereon; a first sub-assembly including first and second driving circuits, first and second wiring substrates, and a connector, the first and second wiring substrates mounting the first and second driving circuits, respectively, the connector connecting the first and second wiring substrates to each other so as to position the second wiring substrate above the first wiring substrate, the first driving circuit driving the thermoelectric element, the second driving circuit driving the first driving circuit; and a housing having a mounting space formed by a first wall, a second wall opposite to the first wall, a third wall, a fourth wall opposite to the third wall, and an inner bottom surface connecting the first, the second, the third and the fourth wall, the housing encasing the primary assembly, the thermoelectric element, and wherein the thermoelectric controller changes the wavelength of light emitted from the light-emitting device by controlling the temperature thereof.