Blue-output laser diode draws a crowd on the way to 10,000 hours
Nichia Chemical Industries (Anan, Japan) has exceeded 3000 hours of continuous-wave (CW) operation for its gallium nitride (GaN) blue-emitting laser diodes by using a Peltier cooler to maintain a device case temperature of 20°C. The company expects its devices to surpass a lifetime of 10,000 hours. The 10,000-hour lifetime projected by Nichia represents an order of magnitude improvement over the September Nichia announcement of 1000 hours (see Laser Focus World, November 1997, p. 16). The projection at a case temperature of 20°C is based on stable operation of the device at 50°C for more than 1000 hours and an observed order-of-magnitude increase in longevity for previous GaN laser diodes when cooled from 50°C to 20°C. During a crowded presentation at the 1997 IEEE/LEOS meeting in San Francisco, CA, Shuji Nakamura of Nichia flourished a blue-output laser-diode pointer and said that the most current Nichia device emits at 404 nm.
The influence of Nichia`s achievements to date was further evidenced by announcements from the Xerox Palo Alto Research Center (Palo Alto, CA) and Hewlett-Packard Laboratories (Palo Alto, CA) in late October and mid-November, respectively, that they had achieved pulsed operation of GaN laser diodes with wavelengths just above 400 nm.