Optical Coherence Tomography with a nonlinear interferometer in the high parametric gain regime

TL;DR

This paper demonstrates optical coherence tomography using a high-gain nonlinear interferometer, which offers improved sensitivity and efficiency over low-gain setups, enabling better imaging with standard detectors.

Contribution

The work introduces a high-gain SU(1,1) nonlinear interferometer for OCT, surpassing low-gain methods by increasing photon flux and sensitivity, and enabling use of standard spectrometers.

Findings

Higher photon flux improves image quality and reduces acquisition time.

Enhanced sensitivity to small losses and amplification before detection.

Standard spectrometers can be used instead of high-sensitivity detectors.

Abstract

We demonstrate optical coherence tomography based on an SU(1,1) nonlinear interferometer with high-gain parametric down-conversion. For imaging and sensing applications, this scheme promises to outperform previous experiments working at low parametric gain, since higher photon fluxes provide lower integration times for obtaining high-quality images. In this way one can avoid using single-photon detectors or CCD cameras with very high sensitivities, and standard spectrometers can be used instead. Other advantages are: higher sensitivity to small loss and amplification before detection, so that the detected light power considerably exceeds the probing one.