Tunable Optical Coherence Tomography in the Infrared Range Using Visible Photons

TL;DR

This paper demonstrates a novel IR optical coherence tomography method that uses visible photons for detection, enabling tunable, non-invasive 3D imaging in the infrared range without IR detectors.

Contribution

It introduces a proof-of-concept technique utilizing nonclassical photon interference for IR imaging with visible photon detection, broadening IR imaging capabilities.

Findings

Enables IR imaging using only visible photon detectors

Offers broad tunability and good resolution in IR OCT

Facilitates versatile 3D imaging without IR equipment

Abstract

We report a proof-of-concept demonstration of a tunable infrared (IR) optical coherence tomography (OCT) technique with detection of only visible range photons. Our method is based on the nonclassical interference of frequency correlated photon pairs. The nonlinear crystal, introduced in the Michelson-type interferometer, generates photon pairs with one photon in the visible and another in the IR range. The intensity of detected visible photons depends on the phase and loss of IR photons, which interact with the sample under study. This enables us to perform imaging and characterize sample properties in the IR range by detecting visible photons. The technique possesses broad tunability and yields a fair axial and lateral resolution. The work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range equipment.