Quantum-enhanced stimulated Raman scattering

Zhaolin Li, Guo-qing Zheng, Daozhong Zhang

A. Laubereau

Zicong Xu, Kenichi Oguchi, Yoshitaka Taguchi +5 more

Quantum-enhanced stimulated Raman scattering (QESRS) microscopy is expected to realize molecular vibrational imaging with sub-shot-noise sensitivity, so that weak signals buried in the laser shot noise can be uncovered. Nevertheless, the sensitivity of previous QESRS did not exceed that of state-of-the-art stimulated Raman scattering (SOA-SRS) microscopes mainly because of the low optical power (3 mW) of amplitude squeezed light [Nature594, 201 (2021)10.1038/s41586-021-03528-w]. Here, we present QESRS based on quantum-enhanced balanced detection (QE-BD). This method allows us to operate QESRS in a high-power regime (>30 mW) that is comparable to SOA-SRS microscopes, at the expense of 3 dB sensitivity drawback due to balanced detection. We demonstrate QESRS imaging with 2.89 dB noise reduction compared with classical balanced detection scheme. The present demonstration confirms that QESRS with QE-BD can work in the high-power regime, and paves the way for breaking the sensitivity of SOA-SRS microscopes.

Pavel A Apanasevich, D. N. Ordabaev

Zicong Xu, Kenichi Oguchi, Sho Nitanai +3 more

In this paper, we propose an approach for implementing quantum-enhanced stimulated Raman scattering (QESRS) microscopy using a dual-polarization scheme. This approach has advantages for high-power operation and enables ultrasensitive Raman detection of molecular vibrational mode symmetry. To demonstrate the feasibility and effectiveness of our technique, we present both the theoretical framework and experimental results of dual-polarization QESRS. Our technique resulted in a noticeable reduction of noise on both parallel and orthogonal QESRS spectra as well as on the depolarization ratio spectra. These results validate the potential of our approach for achieving high-speed QESRS imaging with sub-shot-noise sensitivity.

V. A. Zubov, M. M. Sushchinskiǐ, I. K. Shuvalov