Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES)

Fourier-Transform Infrared Spectroscopy with Near-Infrared Light

Chiara Lindner, Jachin Kunz, Simon J. Herr, Jens Kießling, Sebastian Wolf, Frank Kühnemann

Published Jan 1, 2021• 0 citations
Publisher

Abstract

Nonlinear interferometers using correlated photon pairs allow mid-infrared spectroscopy with near-infrared detection. In our work, we combine nonlinear interferom- etry with a measurement scheme and analysis in analogy to classical Fourier-transform spectroscopy, which enhances the spectroscopic performance.
DOI
10.1364/fts.2021.fm2f.4

Related papers

High resolution Fourier-transform mid-infrared spectroscopy using nonlinear interferometers

Jachin Kunz, Chiara Lindner, Simon J. Herr +3 more

Nonlinear interferometers based on correlated photon pairs allow mid-infrared spectroscopy by measuring only near-infrared photons with a silicon-based detector, which offers higher detectivities than mid-infrared detectors. Here, we use the nonlinear interferometer not only to determine the transmission of a sample but also for spectral analysis - analogue to classical Fourier transform infrared (FTIR) spectrometers. The Quantum FTIR analyzes the absorption of gas mixtures with high spectral resolution over a broad mid-infrared wavelength range. Improved emission rates of the photon pair source yield sensitivities similar to a classical FTIR despite an extremely low light exposure on the sample.

Optical and Quantum Sensing and Precision Metrology II•Mar 8, 2023•1 citation

Nonlinear interferometers for Fourier-transform infrared spectroscopy with visible light

Chiara Lindner, Jachin Kunz, Sebastian Wolf +2 more

Nonlinear interferometers based on non-degenerate spontaneous parametric down-conversion (SPDC) create a link between separate spectral ranges. This allows for measurements in remote spectral regions while detecting light in easily accessible wavelengths. In our work, we use periodically poled lithium niobate to create correlated signal (visible or near-infrared) and idler (mid-infrared) photon pairs. Using a nonlinear interferometer in Michelson geometry, we obtain broadband mid-infrared spectra from light detected with a silicon avalanche photodiode. Combining the nonlinear interferometer with a measurement scheme in close analogy to classical Fourier-transform infrared spectroscopy allows for sub-wavenumber spectral resolution, which opens up possibilities for applications such as precise spectroscopic gas analysis.

Nonlinear Frequency Generation and Conversion: Materials and Devices•Mar 4, 2021•0 citations

Mid-IR hyperspectral imaging with undetected photons

Marlon Placke, Chiara Lindner, Felix Mann +4 more

By combining a nonlinear interferometer in imaging-mode with Fourier-transform spectroscopy, we realize broadband mid-infrared hyperspectral acquisition with undetected photons. We demonstrate the novel imaging technique on polymer and bio-tissue samples using only near-infrared silicon-based cameras.

Quantum 2.0 Conference and Exhibition•Jan 1, 2024•0 citations

Quantum Fourier-Transform Infrared Spectroscopy for Complex Transmittance Measurements

Yu Mukai, Masaya Arahata, Toshiyuki Tashima +2 more

Harnessing the quantum interference of the pair generation processes, infrared quantum spectroscopy, based on nonlinear interferometers with visible-infrared photon-pair sources, enables the extraction of the infrared optical properties of a sample through visible photon detection without the need for an infrared optical source or detector. We develop a theoretical framework for quantum Fourier-transform infrared (QFTIR) spectroscopy. The proposed Fourier analysis method, which fully utilizes the phase information in the interferogram, allows us to determine the complex transmittance and optical constants for a sample in a simple setup without the use of any dispersive optics for spectral selection. In the experimental demonstrations, the transmittance spectrum of a bandpass filter and the refractive index of silica glass are measured in the near-infrared region using QFTIR operated in a low gain regime; these results agree well with the independently measured spectrum using a conventional spectrometer and an value estimated from references. These demonstrations prove the validity and great potential of QFTIR spectroscopy.

Physical Review Applied•Mar 8, 2021•48 citations

Spectral resolution of quantum Fourier transform infrared spectroscopy using pulsed laser excitation

Jasleen Kaur, Yu Mukai, Ryo Okamoto +1 more

In recent years, nonlinear quantum interferometry has been widely explored for applications like spectroscopy, optical coherence tomography, and imaging [1]. Quantum infrared spectroscopy (QIRS) uses quantum interference of generation processes of frequency-entangled visible-IR photon pairs to perform infrared spectroscopy using visible light sources and silicon-based detectors [2]. This technique utilizes a nonlinear quantum interferometer configuration where the generated IR photons pass through the sample, and the correlated visible photons are detected. The change in the detected visible photon flux with and without the sample helps extract the complex transmittance of the sample in the IR region.

JSAP-OSA Joint Symposia•Jan 1, 2024•0 citations

Quantum Fourier Transform Infrared Spectroscopy: Evaluation, Benchmarking, and Prospects

Paul Gattinger, Andreas Wolfgang Schell, Sven Ramelow +2 more

Sensing with undetected photons has enabled new, unconventional approaches to Fourier transform infrared spectroscopy (FT-IR). Leveraging properties of non-degenerate entangled photon pairs, mid-infrared (mid-IR) information can be accessed in the near-infrared (near-IR) spectral domain to perform mid-IR spectroscopy with silicon-based detection schemes. Here, we address practical aspects of vibrational spectroscopy with undetected photons using a quantum FT-IR (QFT-IR) implementation. The system operates in the spectral range from around 3000 cm −1 to 2380 cm −1 (detection at around 12 500 cm −1 ) and possesses only 68 pW of mid-IR probing power for spectroscopic measurements with a power-dependence of the signal-to-noise ratio of 1.5 × 10 5 mW −1/2 . We evaluate the system’s short- and long-term stability and experimentally compare it to a commercial FT-IR instrument using Allan–Werle plots to benchmark our QFT-IR implementation’s overall performance and stability. In addition, comparative qualitative spectroscopic measurements of polymer thin films are performed using the QFT-IR spectrometer and a commercial FT-IR with identical resolution and integration times. Our results show under which conditions QFT-IR can practically be competitive or potentially outperform conventional FT-IR technology.

arXiv:2503.13233•Applied Spectroscopy•May 21, 2025•7 citations
Nonlinear interferometers based on correlated photon pairs allow mid-infrared spectroscopy by measuring only near-infrared photons with a silicon-based detector, which offers higher detectivities than mid-infrared detectors. Here, we use the nonlinear interferometer not only to determine the transmission of a sample but also for spectral analysis - analogue to classical Fourier transform infrared (FTIR) spectrometers. The Quantum FTIR analyzes the absorption of gas mixtures with high spectral resolution over a broad mid-infrared wavelength range. Improved emission rates of the photon pair source yield sensitivities similar to a classical FTIR despite an extremely low light exposure on the sample.
Nonlinear interferometers based on non-degenerate spontaneous parametric down-conversion (SPDC) create a link between separate spectral ranges. This allows for measurements in remote spectral regions while detecting light in easily accessible wavelengths. In our work, we use periodically poled lithium niobate to create correlated signal (visible or near-infrared) and idler (mid-infrared) photon pairs. Using a nonlinear interferometer in Michelson geometry, we obtain broadband mid-infrared spectra from light detected with a silicon avalanche photodiode. Combining the nonlinear interferometer with a measurement scheme in close analogy to classical Fourier-transform infrared spectroscopy allows for sub-wavenumber spectral resolution, which opens up possibilities for applications such as precise spectroscopic gas analysis.
Harnessing the quantum interference of the pair generation processes, infrared quantum spectroscopy, based on nonlinear interferometers with visible-infrared photon-pair sources, enables the extraction of the infrared optical properties of a sample through visible photon detection without the need for an infrared optical source or detector. We develop a theoretical framework for quantum Fourier-transform infrared (QFTIR) spectroscopy. The proposed Fourier analysis method, which fully utilizes the phase information in the interferogram, allows us to determine the complex transmittance and optical constants for a sample in a simple setup without the use of any dispersive optics for spectral selection. In the experimental demonstrations, the transmittance spectrum of a bandpass filter and the refractive index of silica glass are measured in the near-infrared region using QFTIR operated in a low gain regime; these results agree well with the independently measured spectrum using a conventional spectrometer and an value estimated from references. These demonstrations prove the validity and great potential of QFTIR spectroscopy.
In recent years, nonlinear quantum interferometry has been widely explored for applications like spectroscopy, optical coherence tomography, and imaging [1]. Quantum infrared spectroscopy (QIRS) uses quantum interference of generation processes of frequency-entangled visible-IR photon pairs to perform infrared spectroscopy using visible light sources and silicon-based detectors [2]. This technique utilizes a nonlinear quantum interferometer configuration where the generated IR photons pass through the sample, and the correlated visible photons are detected. The change in the detected visible photon flux with and without the sample helps extract the complex transmittance of the sample in the IR region.
Sensing with undetected photons has enabled new, unconventional approaches to Fourier transform infrared spectroscopy (FT-IR). Leveraging properties of non-degenerate entangled photon pairs, mid-infrared (mid-IR) information can be accessed in the near-infrared (near-IR) spectral domain to perform mid-IR spectroscopy with silicon-based detection schemes. Here, we address practical aspects of vibrational spectroscopy with undetected photons using a quantum FT-IR (QFT-IR) implementation. The system operates in the spectral range from around 3000 cm −1 to 2380 cm −1 (detection at around 12 500 cm −1 ) and possesses only 68 pW of mid-IR probing power for spectroscopic measurements with a power-dependence of the signal-to-noise ratio of 1.5 × 10 5 mW −1/2 . We evaluate the system’s short- and long-term stability and experimentally compare it to a commercial FT-IR instrument using Allan–Werle plots to benchmark our QFT-IR implementation’s overall performance and stability. In addition, comparative qualitative spectroscopic measurements of polymer thin films are performed using the QFT-IR spectrometer and a commercial FT-IR with identical resolution and integration times. Our results show under which conditions QFT-IR can practically be competitive or potentially outperform conventional FT-IR technology.