Sub-shot-noise-limited nonlinear optical detection of infrared light modulation

Summary form only given. We report a new quantum detection scheme based on nonlinear optical frequency doubling, which converts the incident fundamental IR photons to the secondharmonic blue photons before entering photoelectric detectors. Our scheme is shown in which second-harmonic generation (SHG) is considered as a part of detector (or meter) in order to detect the modulation signals carried in the input IR beam.