Stimulated-Raman-Scattering Metrology

Abstract

Frequency combs have revolutionized optical frequency metrology, allowing one to determine highly accurate transition frequencies of a wealth of molecular species. Despite a recognized scientific interest, these progresses have only marginally benefited infrared-inactive transitions, due to their inherently weak cross-sections. Here we overcome this limitation by introducing stimulated-Raman-scattering metrology, where a frequency comb is exploited to calibrate the frequency detuning between the pump and Stokes excitation lasers. We apply this approach to molecular hydrogen to test quantum electrodynamics. We measure the transition frequency of the Q(1) fundamental line of H${}_2$ around 4155 cm${}^{-1}$ with few parts-per-billion uncertainty, which is comparable to the theoretical benchmark of ab initio calculations and more than a decade better than the experimental state of the art. Our comb-calibrated stimulated Raman scattering spectrometer extends the toolkit of optical frequency metrology as it can be applied, with simple technical changes, to many other infrared-inactive transitions, over a 50-5000 cm${}^{-1}$ range that covers also purely rotational bands.

References in corpus (11)

• 20 years of developments in optical frequency comb technology and applications
• Probing QED and fundamental constants through laser spectroscopy of vibrational transitions in HD+
• Bounds on fifth forces from precision measurements on molecules
• Proton-Electron Mass Ratio from Laser Spectroscopy of HD${}^{+}$ at the Part-Per-Trillion Level
• Rovibrational energy levels of the hydrogen molecule through nonadiabatic perturbation theory
• QED effects in molecules: test on rotational quantum states of H${}_2$
• Lamb-dips and Lamb-peaks in the saturation spectrum of HD
• Sub-ppb measurement of a fundamental band rovibrational transition in HD
• Ultra-high finesse cavity-enhanced spectroscopy for accurate tests of quantum electrodynamics for molecules
• Bending modes metrology in the 14-15 $\mu$m region
• A Stimulated Raman Loss spectrometer for metrological studies of quadrupole lines of hydrogen isotopologues

Cited by in corpus (1)

• A Stimulated Raman Loss spectrometer for metrological studies of quadrupole lines of hydrogen isotopologues