Noise current investigations of g–r noise limited and shot noise limited QWIPs

We report on the experimental determination of the different contributions to the noise current in quantum-well infrared photodetectors (QWIPs). A detailed description of the measurement set-up and experimental methods is given. The noise properties of conventional bound-to-continuum QWIPs and four-zone QWIPs will be discussed. The noise current of these devices is dominated by g–r noise and by shot noise, respectively.