Interferometric quantum spectroscopy with undetected photons via distinguishability modulation

Area of Science:

• Quantum Optics
• Spectroscopy
• Quantum Information Science

Background:

• Quantum spectroscopy with undetected photons (QSUP) leverages quantum entanglement for novel spectroscopic applications.
• Existing QSUP methods often require co-located light-matter interactions and photon detection.

Purpose of the Study:

• To demonstrate a high-resolution and remote-measurement QSUP system.
• To enable spectrally and spatially separated light-matter interactions and photon detections.

Main Methods:

• Utilized a dual-stimulated parametric down-conversion scheme with an optical frequency-comb pump.
• Employed an ultra-narrow coherent seed beam in the idler mode to generate path-entangled photon pairs.
• Used a Fabry-Pérot cavity as a sample to modulate photon distinguishability and demonstrate frequency resolution.

Main Results:

• Successfully demonstrated a high-resolution QSUP system capable of remote measurements.
• Showcased that frequency resolution is determined by the linewidth of the coherent seed laser.
• Observed modulation of interference fringe visibility directly linked to photon distinguishability.

Conclusions:

• The developed remote QSUP system offers high spectral and spatial resolution.
• This advancement paves the way for quantum spectroscopy with enhanced resolution capabilities.
• The technique is suitable for applications requiring non-invasive or remote sensing.