Superlattice Tunneling Detectors operating at lambda = 10 um, based on Quantum Well Intersubband Absorption

We demonstrate a novel 10.8 um superlattice infrared detector based on doped quantum wells of GaAs/A1GaAs. Intersubband resonance radiation excites an electron from the ground state into the first excited state, where it rapidly tunnels out producing a photocurrent. We achieve a narrow bandwidth (10%) photosensitivity with a responsivity of 0.52 A/W and an estimated speed of 45 psec.