A heat sink with a plurality of lead wires connected to the power source apparatus according to this embodiment; First and second temperature compensation type thermoelectric element having a second electrode that is connected to at least two of said power lead being arranged on the heat sink upper side; Is mounted on the thermal element temperature-compensated image side, a light source element and the monitoring element is a silicon optical bench is mounted on the top surface; And is a lens arranged at a position where the optical axis alignment of the light output from the light source device, coupled to the heat sink can member for housing the temperature compensation type thermoelectric element and the silicon optical bench in the inner space; includes the silicon optical bench includes a first reflective surface that reflects the light output from the light source toward the lens element, and; Characterized by including the; second reflection surface for reflecting the light output from the light source element toward the monitoring device.