Sequential multiphoton strategy for semiconductor-based terahertz detectors

A semiconductor-based terahertz-detector strategy, exploiting a bound-to-bound-to-continuum architecture, is presented and investigated. In particular, a ladder of equidistant energy levels is employed, whose step is tuned to the desired detection frequency and allows for sequential multiphoton absorption. Our theoretical analysis demonstrates that the proposed multisubband scheme could represent a promising alternative to conventional quantum-well infrared photodetectors in the terahertz spectral region.