Patent ID: 6842567

Claim:
A power efficient assembly for applying a temperature gradient to a refractive index grating provided in a section of optical fiber, said assembly comprising: a heat conductive elongated element having opposite first and second ends and a longitudinal axis extending therebetween, said elongated element having a fiber-receiving area along the longitudinal axis shaped for receiving said section of optical fiber therealong in continuous thermal contact with the elongated element; a first heat pumping device for maintaining the first end of the elongated element at a first temperature and a second heat pumping device for maintaining the second end of the elongated element at a second temperature different from the first temperature, thereby applying said temperature gradient to the refractive index grating, each of the first and second heat pumping devices having a top side in thermal contact with a corresponding end of the elongated element and a bottom side opposed thereto, in operation, the first heat pumping device pumping heat from the top to the bottom side thereof and the second heat pumping device pumping heat from the bottom to the top side thereof; and a heat recirculation member having opposite first and second ends respectively in thermal contact with the bottom sides of the first and second heat pumping devices, in operation, the heat recirculation member recuperating heat from the bottom side of the first heat pumping device and recirculating said heat to the bottom side of the second heat pumping device.