Presentation
9 March 2022 Stimulated Raman scattering spectroscopy with quantum-enhanced balanced detection scheme
Author Affiliations +
Abstract
Quantum-enhanced stimulated Raman scattering (QE-SRS) becomes a powerful method for high-sensitivity molecular vibrational spectroscopy and imaging by breaking the shot-noise-limited sensitivity of classical SRS. However, it’s still challenging to achieve quantum-enhancement with typical pulse power (<10-mW) for SRS. Although amplitude-squeezing technique was utilized in the previous QE-SRS, it limits the available optical power by its deamplification or optical loss at asymmetric beamsplitter. To circumvent this problem, we propose and demonstrate SRS spectroscopy with quantum-enhanced balanced detection (QE-BD) scheme, where squeezed vacuum (SQV) is combined with a strong local oscillator (LO) to enhance the sensitivity of SRS. We generated SQV at the central wavelength of 844-nm, using a periodically-poled stoichiometric LiTaO3 waveguide. Picosecond LO light is modulated by a spatial light modulator to achieve spatial matching with SQV , and resultant high squeezing level. At each photodiode, LO has ~10-mW optical power, and –3.1-dB squeezing level was observed. To obtain the QE-SRS spectrum of dimethyl sulfoxide-d6 (d-DMSO), we scanned the wavelength of Stokes laser by a high-speed spectral scanner composed of a grating and galvanometric scanner . The QE-SRS spectrum in the wavenumber range of 1950-2300-cm-1 was acquired with 2.1-dB signal-to-noise ratio (SNR) improvement compared with classical shot-noise-limited SRS under balanced-detection. The proposed QE-BD SRS paves the way for QE-SRS with high-power pulses, and shows a potential to exceed the SNR of state-of-the-art classical SRS system without quantum enhancement
Conference Presentation
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kenichi Oguchi, Zicong Xu, Yoshitaka Taguchi, Yuki Sano, Yu Miyawaki, Kazuhiro Katoh, and Yasuyuki Ozeki "Stimulated Raman scattering spectroscopy with quantum-enhanced balanced detection scheme", Proc. SPIE PC12016, Optical and Quantum Sensing and Precision Metrology II, PC120163D (9 March 2022); https://doi.org/10.1117/12.2608735
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KEYWORDS
Spectroscopy

Raman scattering

Raman spectroscopy

Imaging spectroscopy

Signal to noise ratio

3D scanning

Laser scanners

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