Optical Coherence Tomography with a Nonlinear Interferometer in the High Parametric Gain Regime

We demonstrate optical coherence tomography based on an SU(1,1) nonlinearinterferometer with high-gain parametric down-conversion. For imaging andsensing applications, this scheme promises to outperform previous experimentsworking at low parametric gain, since higher photon fluxes provide lowerintegration times for obtaining high-quality images. In this way one can avoidusing single-photon detectors or CCD cameras with very high sensitivities, andstandard spectrometers can be used instead. Other advantages are: highersensitivity to small loss and amplification before detection, so that thedetected light power considerably exceeds the probing one.