Advances in the Theory of Gas-Cell Atomic Frequency Standards

Harish Bahadur, R. Parshad

David A. Howe

Salvatore Micalizio, Aldo Godone

We theoretically describe Raman-Ramsey resonances in an optically thick atomic vapor. Some parameters of interest for frequency standard applications, including light-shift, contrast and linewidth of the central Ramsey fringe are calculated at different temperatures of the atomic vapor. Calculations are done for either Cs and Rb vapor cells with buffer gas. The theory is compared to already existing experimental results obtained with Cs cells and predictions are reported for Rb cells.

Jacques Vanier, Cipriana Tomescu

James C. Camparo, R. P. Frueholz

Recently, there has been considerable interest in the use of single-mode diode lasers in atomic frequency standards. In the present paper theoretical calculations are performed in order to quantify the expected performance improvement upon incorporation of diode lasers in rubidium gas cell atomic frequency standards. We assume that clock signal shot noise, the diode laser’s quantum noise, and diode laser frequency locking noise all contribute to the atomic frequency standard’s stability. Our results indicate that white-noise Allan variances of ∼6×10−15/(τ)1/2 are possible if enhanced cavity Q diode lasers are employed, whereas for presently available commercial diode lasers we predict white-noise Allan variances of ∼3×10−14/(τ)1/2. These variances represent a 2–3 orders of magnitude improvement in frequency stability over that currently obtained with rubidium gas cell atomic clocks.

Jiqing Lian, Qiaohui Yang, Tianyu Liu +8 more

This study investigates the application of miniature quantum references within small-scale optical atomic frequency standards, utilizing a diminutive 87 Rb glass cell, dimensions of 6 mm × 6 mm × 6 mm, to establish a quantum frequency standard.By employing the transition spectrum from 5 2 S 1/2 F = 2 to 5 2 P 3/2 F 0 =3, this study successfully demonstrates the development of a compact rubidium atomic optical frequency standard via modulation transfer spectroscopy (MTS).Subsequent to frequency stabilization, the 780 nm clock laser exhibits a linewidth of 6.9 kHz, and its out-of-loop short-term stability reaches 4.1 × 10 -13 @ 1 s, as confirmed through beat frequency analysis.This research not only provides a practical blueprint for the development of small optical atomic frequency standards but also lays down essential groundwork for future advancements in chip-level optical frequency standard technologies.