Stimulated Raman scattering spectroscopy with quantum-enhanced balanced detection

Abstract

Quantum-enhanced stimulated Raman scattering (QE-SRS) is a promising technique for highly sensitive molecular vibrational imaging and spectroscopy surpassing the shot noise limit. However, the previous demonstrations of QE-SRS utilized rather weak optical power which hinders from competing with the sensitivity of state-of-the-art SRS microscopy and spectroscopy using relatively high-power optical pulses. Here, we demonstrate SRS spectroscopy with quantum-enhanced balanced detection (QE-BD) scheme, which works even when using high-power optical pulses. We used 4-ps pulses to generate pulsed squeezed vacuum at a wavelength of 844 nm with a squeezing level of −3.28 ± 0.12 dB generated from a periodically-poled stoichiometric LiTaO3 waveguide. The squeezed vacuum was introduced to an SRS spectrometer employing a high-speed spectral scanner to acquire QE-SRS spectrum in the wavenumber range of 2000–2280 cm-1 within 50 ms. Using SRS pump pulses with an average power of 11.3 mW, we successfully obtained QE-SRS spectrum whose SNR was better than classical SRS with balanced-detection by 2.27 dB.

Stimulated Raman Scattering Microscopy: A Review

“…To improve the signal-to-noise ratio (SNR), the squeezed light-enhanced SRS (SQ-SRS) has been demonstrated in both SRS spectroscopy [116] and SRS microscopy [117]. In [116], SRS spectroscopy was demonstrated with quantum-enhanced balanced detection (QE-BD).…”

“…To improve the signal-to-noise ratio (SNR), the squeezed light-enhanced SRS (SQ-SRS) has been demonstrated in both SRS spectroscopy [116] and SRS microscopy [117]. In [116], SRS spectroscopy was demonstrated with quantum-enhanced balanced detection (QE-BD). In Figure 4, the QE-SRS spectra are measured by observing the output signal of the LIA on an oscilloscope (OSC), which is shown [116].…”

Quantum-enhanced stimulated Raman scattering microscopy toward breaking the shot noise limit in high-power regime

“…We assume that spatial pattern of SQV is the same as that of fundamental mode of the OPA waveguide. Thus, we calculate the spatial profile of fundamental mode by mode-solver (Modesolverpy 25 ), and use the acquired spatial profile as the target pattern for LO 14 .…”

“…To overcome shot-noise-limited sensitivity of SRS microscopy, quantum-enhanced (QE-) SRS microscopy is expected as a promising technique [12][13][14][15] . R. B. de Andrade et al demonstrated QE-SRS by using continuous light source, where continuous light was mixed with squeezed vacuum at asymmetric beamsplitter, and used as SRS Stokes light.…”

“…In this paper, we demonstrate QE-SRS microscopy with high-power squeezed pulses as SRS pump pulses by using quantum-enhanced balanced detection (QE-BD) scheme [14][15][16] , where picosecond squeezed vacuum is injected to a balanced detection SRS microscope to cancel out the shot noise. QE-BD scheme is advantageous to realize QE-SRS with highpower SRS pump pulse (several tens of milliwatt), which is often utilized in SRS microscopy for cell and tissue imaging.…”