Selective reflection from a potassium atomic layer with a thickness as small as λ/13

Abstract

We demonstrate that a method using the derivative of the selective reflection signal from a nanocell is a convenient and robust tool for atomic laser spectroscopy, achieving a nearly Doppler-free spectral resolution. The recorded linewidth of the signal from a potassium-filled cell, whose thickness lies in the range 350 − 500 nm, is 18 times smaller than the Doppler linewidth (∼ 900 MHz full width at half maximum) of potassium atoms. We also show experimentally a sign oscillation of the reflected signal's derivative with a periodicity of λ/2 when varies from 190 to 1200 nm confirming the theoretical prediction. We report the first measurement of the van der Waals atom-surface interaction coefficient C 3 = 1.9 ± 0.3 kHz × µm 3 of potassium 4S 1/2 → 4P 3/2 transitions with the nanocell's sapphire windows, demonstrating the usefulness and convenience of the derivative of selective reflection technique for cell thicknesses in the range 60 − 120 nm.

Features of magnetically-induced atomic transitions of the Rb D1 line studied by a Doppler-free method based on the second derivative of the absorption spectra

“…In the case of a natural mixture of 85 Rb and 87 Rb, the number of closely spaced atomic transitions can reach several tens. Sub-Doppler resolution with a simple singlebeam geometry, providing a linear response in atomic media for transmission, fluorescence, and selective reflection experiments, can be achieved using optical nanocells (NCs) with a thickness of the order of resonant radiation wavelength [12,13]. Even in this case, however, some spectral features cannot be completely resolved, due to residual Doppler-overlapped profiles [14].…”

Исследование взаимодействия атомов Cs с поверхностью сапфира с использованием сверхтонкой ячейки и метода вычисления второй производной спектра поглощения паров

“…красными", а переходов F g = 3 → F e = 2, 3, 4 - рами щелочных металлов, оказались очень удобными для исследования vdW взаимодействия атомов с поверхностью, поскольку в этом случае расстояние L может быть значительно меньшим, вплоть до десятков нанометров. Используя такие процессы, как резонансное поглощение в парах атомов [16,17], селективное отражение лазерного излучения от наноячейки [10,[18][19][20], резонансная флуоресценция паров атомов [21,22] и фарадеево вращение в парах металлов [23,24], коэффициенты vdW взаимодействия C 3 были измерены для атомов Cs…”

Features of Magnetically-induced atomic transitions of Rb D$_1$ line studied by Doppler-free method based on the second derivative of the absorption spectra

“…Indeed, in the case of a natural mixture of 85 Rb and 87 Rb, the number of closely spaced atomic transitions can reach several tens. Sub-Doppler resolution with simple single-beam geometry, providing a linear response of atomic media for transmission, fluorescence, and selective reflection experiments, can be attained using optical nanocells (NCs) with a thickness of the order of resonant radiation wavelength [12,13]. But even in this case, some spectral features cannot be completely resolved due to residual Doppler-overlapped profiles [14].…”