Abstract
Mid-infrared photothermal (MIP) measurement probes refractive-index changes induced by mid-infrared (MIR) absorption using visible or near-infrared light and has recently emerged as a powerful modality for MIR spectro-imaging in the life sciences. Reducing measurement noise allows the probe power to be lowered without compromising the signal-to-noise ratio (SNR), thereby mitigating the risk of sample damage. However, even in the absence of classical noise, the SNR of conventional MIP measurements using a classical coherent probe is fundamentally limited by shot noise. Here, we demonstrate sub-shot-noise MIP measurement using twin beams generated through seeded optical parametric amplification. Balanced detection of the twin beams suppresses the noise by more than 5 dB below the shot-noise level established using a coherent beam. As a proof-of-principle demonstration, we measure the MIP signal from liquid water using balanced twin-beam detection and achieve an SNR enhancement of more than 2 dB over the balanced coherent-beam detection.
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Publication details
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- Green open access
Cite this article
APA 7
Hashimoto, K., & Ideguchi, T. (2026). Sub-shot-noise mid-infrared photothermal measurements using twin beams. https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams
MLA 9
Hashimoto, Kazuki, and Takuro Ideguchi. "Sub-shot-noise mid-infrared photothermal measurements using twin beams." https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams.
Chicago (author–date)
Hashimoto, Kazuki, and Takuro Ideguchi. 2026. "Sub-shot-noise mid-infrared photothermal measurements using twin beams." https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams.
Harvard
Hashimoto, K. and Ideguchi, T. (2026) 'Sub-shot-noise mid-infrared photothermal measurements using twin beams', Available at: https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams.
Vancouver
Hashimoto K, Ideguchi T. Sub-shot-noise mid-infrared photothermal measurements using twin beams. https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams
IEEE
K. Hashimoto, and T. Ideguchi, "Sub-shot-noise mid-infrared photothermal measurements using twin beams," https://omanscience.com/en/articles/sub-shot-noise-mid-infrared-photothermal-measurements-using-twin-beams.