Joint spectrum of photon pairs measured by coincidence Fourier spectroscopy.
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.
Wasilewski
Wojciech
W
Instiute of Physics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland. wwasil@fuw.edu.pl
Wasylczyk
Piotr
P
Kolenderski
Piotr
P
Banaszek
Konrad
K
Radzewicz
Czesław
C