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Updated: Aug 9, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Joint spectrum of photon pairs measured by coincidence Fourier spectroscopy
Wojciech Wasilewski1, Piotr Wasylczyk, Piotr Kolenderski
1Instiute of Physics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland. wwasil@fuw.edu.pl
Abstract:
We propose and demonstrate a method for measuring the joint spectrum of photon pairs via Fourier spectroscopy. The biphoton spectral intensity is computed from a two-dimensional interferogram of coincidence counts. The method has been implemented for a type-I downconversion source using a pair of common-path Mach-Zehnder interferometers based on Soleil compensators. The experimental results agree well with calculated frequency correlations that take into account the effects of coupling into single-mode fibers. The Fourier method is advantageous over scanning spectrometry when detectors exhibit high dark count rates leading to dominant additive noise.
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