Revisiting optical spectroscopy in a thin vapor cell: mixing of reflection and transmission as a Fabry–Perot microcavity effect

Abstract

Transmission spectroscopy in an ultrathin vapor cell, which has been recently demonstrated as a new method of sub-Doppler spectroscopy in the optical domain, is revisited. We show that, because of an unavoidable Fabry-Perot effect, the observed signal-in transmission spectroscopy and selective reflection spectroscopy as well-is actually an interferometric mixture of the optical responses as provided in transmission and in reflection by a long macroscopic cell. After the derivation of a very general solution, we restrict ourselves to the case of a linear interaction with the resonant laser. We finally discuss the application to a two-level atom for which analytical expressions are given, in the large Doppler limit, for FM transmission and reflection signals.

Hilbert transform: Applications to atomic spectra

“…This could include cases when complex interactions that involve the refractive index occur, for example, when investigating the alteration of the atomic line shape byétalon effects inside a vapor cell [31] or to gain a fuller picture of parity-nonconserving effects in transition-metal vapors [35]. Another potential use is as a diagnostic tool for testing fitting routines; the difference in dispersive spectra is clearer on visual inspection than the differences in a Voight line shape.…”

Relaxation mechanisms affecting magneto-optical resonances in an extremely thin cell: Experiment and theory for the cesiumD1line

“…Early efforts to model these signals focused on the Dicke-type narrowing observed in transmission sigarXiv:1411.2750v1 [physics.atom-ph] 11 Nov 2014 nals when the wall separation was equal to an odd number of half wavelengths [15]. However, for fluorescence signals, this effect is not expected to be significant [16].…”

“…The effect of energy shifts induced by van der Waals interactions with the walls was considered, and for the cesium D 1 line could lead to shifts of the excitation maximum by up to 200 MHz for cell thicknesses around 50 nm [17]. Some of these early studies also applied the optical Bloch equations to a simplified two-level representation with optical pumping losses [15,18], but only in the linear excitation regime for intensities up to several milliwatts per square centimeter and Rabi frequencies less than 10 MHz. More recently, the cesium D 2 line has been studied experimentally and theoretically at somewhat higher powers up to 40 mW/cm 2 using a model based on the optical Bloch equations [19,20], but these models still were based on an open two-level system rather than including all degenerate sublevels.…”

Dependence of four-wave mixing line-shape on micrometric atomic vapor thickness

“…Many authors have demonstrated that, the cell's thickness is the main factor which influences the shape and the magnitude of the spectra of a thin vapor column both in theory and experiment [2][3][4]6]. This modification can be extended to electromagnetically induced transparency (EIT) dips [7,8] and FWM spectroscopy [7].…”