Single-Photon Level Dispersive Fourier Transform

Ultrasensitive Characterization of Noise-Driven Nonlinear Dynamics

authored by: Lynn Sader, Surajit Bose, Anahita Khodadad Kashi, Yassin Boussafa, Raktim Haldar, Romain Dauliat, Philippe Roy, Marc Fabert, Alessandro Tonello, Vincent Couderc, Michael Kues, Benjamin Wetzel
Abstract: Dispersive Fourier transform is a characterization technique that allows directly extracting an optical spectrum from a time domain signal, thus providing access to real-time characterization of the signal spectrum. However, these techniques suffer from sensitivity and dynamic range limitations, hampering their use for special applications in, e.g., high-contrast characterizations and sensing. Here, we report on a novel approach to dispersive Fourier transform-based characterization using single-photon detectors. In particular, we experimentally develop this approach by leveraging mutual information analysis for signal processing and hold a performance comparison with standard dispersive Fourier transform detection and statistical tools. We apply the comparison to the analysis of noise-driven nonlinear dynamics arising from well-known modulation instability processes. We demonstrate that with this dispersive Fourier transform approach, mutual information metrics allow for successfully gaining insight into the fluctuations associated with modulation instability-induced spectral broadening, providing qualitatively similar signatures compared to ultrafast photodetector-based dispersive Fourier transform but with improved signal quality and spectral resolution (down to 53 pm). The technique presents an intrinsically unlimited dynamic range and is extremely sensitive, with a sensitivity reaching below the femtowatt (typically 4 orders of magnitude better than ultrafast dispersive Fourier transform detection). We show that this method can not only be implemented to gain insight into noise-driven (spontaneous) frequency conversion processes but also be leveraged to characterize incoherent dynamics seeded by weak coherent optical fields.
Organisation(s): Institute of Photonics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
External Organisation(s): Universite de Limoges
Type: Article
Journal: ACS PHOTONICS
Volume: 10
Pages: 3915-3928
No. of pages: 14
ISSN: 2330-4022
Publication date: 15.11.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Biotechnology, Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1021/acsphotonics.3c00711 (Access: Open)