Mid-IR Laser Diode Raises Operating Temperature

Spectrometrists probing the midinfrared with semiconductor lasers have had to be content with the higher noise and spectral width of pulsed operation or else use cryogenic cooling to achieve continuous-wave (CW) operation. A quantum cascade device developed at Applied Optoelectronics Inc. in Sugar Land, Texas, has taken a step toward bridging this problem.

The laser, centered at 5.2 µm, still required cooling to 210 K to achieve CW operation at 8 mW, but this is within the ability of less-expensive thermoelectric coolers. The company applied material advances and thermal engineering to know-how it licensed from Lucent Technologies Inc. in Murray Hill, N.J. Engineers at Applied Optoelectronics believe they can demonstrate the same results for 4.6-µm devices.