Quantum Optical Induced-Coherence Tomography by a Hybrid Interferometer

TL;DR

This paper introduces a hybrid quantum interferometer combining visible and infrared components, enabling non-invasive optical measurements and tomography using induced-coherence phenomena with potential for practical sensing applications.

Contribution

It presents the first hybrid induced-coherence interferometer integrating Mach-Zehnder and Michelson configurations for enhanced quantum optical measurements.

Findings

Interference visibility matches heralding efficiencies.

Successful demonstration of 3D quantum optical tomography.

Feasibility of undetected-photon sensing techniques.

Abstract

Quantum interferometry based on induced-coherence phenomena has demonstrated the possibility of undetected-photon measurements. Perturbation in the optical path of probe photons can be detected by interference signals generated by quantum mechanically correlated twin photons propagating through a different path, possibly at a different wavelength. To the best of our knowledge, this work demonstrates for the first time a hybrid-type induced-coherence interferometer that incorporates a Mach-Zehnder-type interferometer for visible photons and a Michelson-type interferometer for infrared photons, based on double-pass pumped spontaneous parametric down-conversion. This configuration enables infrared optical measurements via the detection of near-visible photons and provides methods for characterizing the quality of measurements by identifying photon pairs of different origins. The results verify that the induced-coherence interference visibility is approximately the same as the heralding efficiencies between twin photons along the relevant spatial modes. Applications to both time-domain and frequency-domain quantum-optical induced-coherence tomography for three-dimensional test structures are demonstrated. The results prove the feasibility of practical undetected-photon sensing and imaging techniques based on the presented structure.