Room-temperature midinfrared two-photon photodetector

We report on a two-photon detector based on resonantly enhanced nonlinear absorption between subbands in InGaAs/InAlAs quantum wells and demonstrate its use as a quadratic autocorrelator for midinfrared pulses. Modified device design allows for device operation at room temperature, which is crucial for applications in practical systems. (c) 2008 American Institute of Physics.