High-accuracy and wide dynamic range frequency-based dispersion spectroscopy in an optical cavity

Cavity ring-down spectroscopy of CO2 near λ = 2.06 µm: Accurate transition intensities for the Orbiting Carbon Observatory-2 (OCO-2) “strong band”

“…Because spectroscopy is only part of the retrieval error budget, line intensities need to be known to a higher accuracy and precision than the XCO2 relative standard uncertainty target, which is 0.3 % for the OCO-2 mission [4]. Only recently have line intensities of such accuracy been reported for CO2 [5], and the demand for improved accuracy continues to generally motivate recent advances in related cavity-enhanced methods (e.g., [6,7]).…”

Ultrahigh finesse cavity-enhanced spectroscopy for accurate tests of quantum electrodynamics for molecules

“…In this letter, we report the most accurate measurement of the position of the weak quadrupole S(2) 2-0 line in D 2 . The spectra were collected with a frequencystabilized cavity ring-down spectrometer (FS-CRDS) linked to an optical frequency comb (OFC) referenced to a primary frequency standard [18,19]. We developed an ultra-high finesse optical cavity (F = 637 000) and we implemented the frequency-agile, rapid scanning spectroscopy (FARS) [20], which allowed us to reduce the absorption noise from 3×10 −10 cm −1 in our previous study [11] to 8×10 −12 cm −1 in the present work.…”

Cavity buildup dispersion spectroscopy

“…Measurements of ultrahigh-fidelity absorption spectra can help validate quantum theory, engineer ultracold chemistry, and remotely sense atmospheres [1][2][3][4] . Recent achievements in cavity-enhanced spectroscopy using either frequency-based dispersion 5 or time-based absorption 6 approaches have set new records for accuracy with uncertainties at the sub-permil level. However, laser scanning 5 or susceptibility to nonlinearities 6…”

“…Recent achievements in cavity-enhanced spectroscopy using either frequency-based dispersion 5 or time-based absorption 6 approaches have set new records for accuracy with uncertainties at the sub-permil level. However, laser scanning 5 or susceptibility to nonlinearities 6…”