Patent ID: 8259765

Claim:
An external-cavity laser module comprising: a package defining an enclosure, said package comprising a base having a surface internal to the enclosure; a thermoelectric cooler within said enclosure, said thermoelectric cooler comprising an upper carrier plate and a lower carrier plate, said lower carrier plate being in thermal contact with said internal surface of said base and said thermoelectric cooler being configured to stabilise the temperature of the upper carrier plate; a laser assembly, housed within said enclosure, comprising a gain medium for emitting an optical beam into an external cavity, said gain medium being thermally coupled to the upper carrier plate of the thermoelectric cooler via at least one thermally conductive element so as to provide a first heat flow path having a first thermal resistance; and a thermal bridge element having first and second arms disposed on opposite ends of an articulated resilient central portion, the first arm placed in thermal contact with the gain medium and the second arm placed in thermal contact with the package, the thermal bridge element providing a second heat flow path having a second thermal resistance between said gain medium and said package, wherein the second thermal resistance is greater than the first thermal resistance, the second thermal resistance being selected to at least partially compensate for thermally induced variations of an optical path length of the external cavity, so as to maintain a substantially stable laser output power; and wherein the first thermal resistance is greater than about 5 K/W.