Fig. 1. The detection wavelength range and operating temperature of existing infrared detectors sourced from references [1−2, 10−11, 15−18]

Fig. 2. (a) Schematic diagram of the working mechanism of quantum well structure; (b) Schematic diagram of 45° edge coupling structure for QWP optical coupling

Fig. 3. Optically pumped terahertz quantum cascade detector. (a) Schematic diagram of single period energy band structure; (b) Schematic diagram of single period working mechanism

Fig. 4. Free carrier absorption mechanism detector. (a) Schematic diagram of energy band structure; (b) Schematic diagram of optical coupling

Fig. 5. Schematic diagram of the energy band of optically pumped hot hole effect terahertz detector. (a) Schematic diagram of the energy band of 0 V; (b) Schematic diagram of the working mechanism without hot carrier injection under negative bias voltage; (c) Schematic diagram of the working mechanism with hot carrier injection

Fig. 6. Energy band diagram of the working mechanism of infrared/terahertz quantum ratchet detector

Fig. 7. Schematic diagram of the quantum ratchet detector (No.1616). (a) Schematic diagram of the device structure; (b) Schematic diagram of the device working mechanism; (c) Photocurrent spectrum measured by FTIR; (d) PL spectrum characterization results

Fig. 8. Schematic diagram of quantum ratchet upconversion device (No.1618). (a) Device structure and material parameter diagram; (b) Low temperature dark current IV results; (c) Photocurrent spectrum measured results by FTIR

Fig. 9. Schematic diagram of MOCVD grown quantum ratchet detector (No.1616-M). (a) Device structure and material parameter diagram; (b) Low-temperature dark current; (c) Photocurrent spectrum measured by FTIR

Fig. 10. The response intensity R of quantum ratchet upconversion device (No: 1618) changes with temperature results chart