Fiber-assisted single-photon spectrograph

TL;DR

This paper presents a fiber-integrated spectrograph that uses chromatic dispersion to temporally stretch ultrafast pulses, enabling high-resolution spectral analysis of single photons with high signal-to-noise ratio.

Contribution

It introduces a novel fiber-assisted single-photon spectrograph leveraging GVD for spectral resolution, combining fiber optics and time-resolved detection.

Findings

Successfully analyzed joint spectral intensity of a parametric downconversion source

Achieved high spectral resolution with single-photon detection

Demonstrated potential for telecom wavelength applications

Abstract

We demonstrate the implementation of a fiber-integrated spectrograph utilizing chromatic group velocity dispersion (GVD) in a single mode fiber. By means of GVD we stretch an ultrafast pulse in time in order to spectrally resolve single photons in the time domain, detected by single photon counting modules with very accurate temporal resolution. As a result, the spectrum of a very weak pulse is recovered from a precise time measurement with high signal to noise ratio. We demonstrate the potential of our technique by applying our scheme to analyzing the joint spectral intensity distribution of a parametric downconversion source at telecommunication wavelength.