A light source module (100) includes a plurality of light emitting diodes (13), a heat dissipation device (30) and a thermoelectric cooler (20). The thermoelectric cooler has a cold side (21) and a hot side (23). The light emitting diodes are in thermal engagement with the cold side of the thermoelectric cooler. The heat dissipation device is in thermal engagement with the hot side of the thermoelectric cooler.