Multicolor infrared detection using two stacks of superlattice structures in a back-to-back configuration

Voltage-controlled multicolor detection with a two-stack GaAs/AlGaAs superl attice structure is reported. Each stack contains a superlattice and curren t blocking layers. The responsivity of each stack has a voltage-tunable spe ctral range and can be turned on or off by controlling the bias polarity. I n a back-to-back configuration of the two stacks, a variable detection rang e with peak wavelength at 5.5, 6.8, 8.5, and 10.8 mu m is achieved by chang ing the applied voltage at 45 K. (C) 2000 American Institute of Physics. [S 0003- 6951(00)05037-3].