Two-color GaN/AlGaN quantum cascade detector at short infrared wavelengths of 1 and 1.7 micron

A two-color GaN-based quantum cascade detector is demonstrated. This photodetector operates simultaneously at a peak wavelength of 1.7 and 1 mu m at room temperature without any external voltage. These peaks correspond, respectively, to the e(1)e(2) and e(1)e(3) intersubband absorption of the active GaN quantum well. The extractor has been designed to allow for efficient transfer of electrons from both the e(2) and e(3) states to the next period. The 1 mu m detected wavelength is the shortest value reported for an intersubband semiconductor based detector. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4707904]