The hyperfine Paschen–Back Faraday effect

Abstract

We investigate experimentally and theoretically the Faraday effect in an atomic medium in the hyperfine Paschen-Back regime, where the Zeeman interaction is larger than the hyperfine splitting. We use a small permanent magnet and a micro-fabricated vapour cell, giving magnetic fields of the order of a tesla. We show that for low absorption and small rotation angles, the refractive index is well approximated by the Faraday rotation signal, giving a simple way to measure the atomic refractive index. Fitting to the atomic spectra, we achieve magnetic field sensitivity at the 10 −4 level. Finally we note that the Faraday signal shows zero crossings which can be used as temperature insensitive error signals for laser frequency stabilization at large detuning. The theoretical sensitivity for 87 Rb is found to be ∼ 40 kHz • C −1 .

Study of the Rb D 2-line splitting in a strong transverse magnetic field with Doppler-free spectroscopy in a nanocell

“…For the case of the usual Rb-filled gas cell with a thickness of L = 0.1-1 cm, the Doppler width is >500 MHz. Apparently that, for the magnetic field strength used in the present study, individual atomic transitions may be resolved only in a pure 87 Rb isotope spectrum [6,12,18].…”

“…In addition to their scientific interest, such studies may find some applications, including (i) development of a frequency reference with frequencies shifted (up to ±15 GHz) relative to parent atomic levels in Rb and Cs; (ii) stabilization of laser frequency with the use of such shifted levels [8]; (iii) development of magnetometer for mapping strongly inhomogeneous magnetic fields with submicron spatial resolution [11]; and (iv) development of Rb vapor optical isolator employing the Faraday effect in a strong magnetic field [6,12]. SYSTEM UNDER STUDY This paper reports the first experimental study of the Rb D 2 -line in a strong transverse magnetic field for the case of π-polarized exciting radiation with the use of the λ/2-method, which provides a high spectral resolution.…”

Widefield microwave imaging in alkali vapor cells with sub-100μm resolution

“…A schematic of our cell is shown in figure 2(c). The cell and microwave device are placed inside an oven, with operating temperatures of 130°C to 140°C chosen to give an optical depth of OD 1 » [37][38][39]. The Rb vapor density is controlled by a cold finger wrapped around the end of the glass-to-metal transition, and the 10°C temperature gradient between the cold finger and the cell helps reduce the deposition rate of Rb and other contaminants on the cell windows.…”

Optical Response of Gas-Phase Atoms at Less thanλ/80from a Dielectric Surface

“…By fitting this high-resolution data to a comprehensive model of the atomic susceptibility, which has previously been used to model transmission and refraction in thermal temperature vapor cells in a range of experimental regimes [6,36,37,[40][41][42][43][44], we extract the atom-surface interaction and thereby calibrate the position of an atom emitting at a particular frequency. Using this method, we are able to detect atoms within 10-15 nm of the dielectric surface.…”