DURHAM, N.C., Feb. 5, 2010 – Nextreme Thermal Solutions Inc. has demonstrated the cooling of a laser diode in a TO-8 package using an embedded thin-film thermoelectric OptoCooler HV14 module. Cooling the laser improves its output performance and reliability. Laser diodes are susceptible to heat, which can adversely affect their output power and wavelength. Manufacturers have traditionally used thermoelectric coolers for temperature control. However, as the photonics industry has moved to smaller, more integrated packaging to reduce costs, conventional thermoelectric coolers have not kept pace with size and heat requirements, so some designers have chosen to place the cooling device outside the package. Cooling the diode by cooling the entire package is an inefficient method of thermal management. Thermoelectric coolers made from thin-films are smaller and thinner than conventional ones and can be embedded in small packages. In addition, thin-film coolers have a low mass, enabling a more rapid thermal response to changing temperatures. The company mounted a laser diode on the active side of a RoHS-compliant OptoCooler HV14 thermoelectric cooler in a TO-8 package. At 85 °C, the <3 × 3-mm module can pump 1.7 W of heat. The cooler can create a temperature differential of up to 50 °C between its hot and cold sides. As part of the demonstration, a test bed was assembled to measure the effects of cooling on laser output and wavelength. When the cooler was turned on, the temperature of the diode quickly dropped from 42 to approximately 21 °C in milliseconds, and the output level of the laser nearly doubled from 0.38 to 0.74 mW at a drive current of 100 mA. An optical spectrum analyzer measured a wavelength shift toward the blue spectrum of approximately 13.6 nm.