Thermistors are very commonly used for narrow temperature-range high-resolution applications, such as in medicine, calorimetry, and near ambient temperature measurements. In particular, Negative Temperature Coefficient (NTC) thermistor is very inexpensive and highly sensitive, whose sensing temperature range and sensitivity are highly limited due to the intrinsic nonlinearity and self-heating p...

tion as an alternative to Si as a semiconductor material for ultra-low-loss power devices. Early development of GaN was carried out in the area of light-emitting devices—green LEDs, lasers, etc.—but its superior performance as noted above and the needs of society led to R&D work for electronic devices being conducted world-wide. Specifically, the AlGaN/GaN HFET structure permits the formation o...

The authors describe a straightforward experimental technique for measuring the facet temperature of a semiconductor laser under high-power operation by analyzing the laser emission itself. By applying this technique to 1-mm-long 980-nm lasers with 6and 9m-wide tapers, they measure a large increase in facet temperature under both continuous wave (CW) and pulsed operation. Under CW operation, th...