Institute of Physics Ministry of Science and Education Republic of Azerbaijan

LINEAR OPTICAL SUB-DOPPLER RAMSEY RESONANCES IN ULTRATHIN GAS CELLS

Azad Ch. Izmailov

ABSTRACT

The paper theoretically establishes and studies the sub-Doppler linear optical Ramsey resonances that arise under certain conditions near centers of optical transitions in the absorption of a sufficiently weak monochromatic light beam during its stationary propagation in the normal direction through an ultrathin gas cell whose internal thickness is less than or of the order of the wavelength of this radiation. We consider a situation when the cross section of this beam consists of two coaxial spatially separated regions, with the absorption signal being detected in a comparatively narrow central part of the beam. The paper studies the significant dependence of the linear optical Ramsey resonances, that arise in such an absorption spectrum, on the distance between these regions, as well as on the phase difference between them. In particular, it is shown that if this phase difference is close to π, then instead of absorption, amplification of the central part of the incident beam can occur. The Ramsey resonances under consideration are most clearly manifested when the internal thickness of the gas cell is equal to a small half-integer number of wavelengths of the resonant radiation. However, these resonances do not arise if this thickness is equal to an integer number of such waves. The established Ramsey resonances, under certain conditions, can find application in ultrahigh resolution atomic (molecular) spectroscopy, as well as effective references in compact optical frequency standards.

Keywords: linear optical Ramsey resonances, ultrathin gas cells, ultrahigh resolution spectroscopy, optical frequency standards.
DOI:10.70784/azip.1.2025211

Received: 02.04.2025
Internet publishing: 22.04.2025 AJP Fizika E 2025 02 en p.11-16

AUTHORS & AFFILIATIONS

Institute of Physics, Azerbaijan Republic Ministry of Sciences and Education, Baku, AZ-1073, Azerbaijan
E-mail: izmailov57@yahoo.com

Graphics and Images

Fig.1-2-3-4

[1]   N.F. Ramsey. Molecular Beams, 1990 (Oxford: Oxford University Press).
[2]   W. Demtreder. Laser Spectroscopy: Basic Concepts and Instrumentation, 1996 (Springer-Verlag).
[3]   T.F. Cutler, W.J. Hamlyn, J. Renger, K.A. Whittaker, D. Pizzey, I.G. Hughes, V. Sandogdar and C.S. Adams. Nanostructured alkali-metal vapor cells, Phys. Rev. Applied, 2020, V.14, 034054.
[4]   M. Ducloy. Laser spectroscopy of nanometric gas cells, Europhysics News, 2004, V. 35, 40-42.
[5]   S. Briaudeau, S. Saltiel, G. Nienhuis, D. Bloch and M. Ducloy. Coherent Doppler narrowing in a thin vapor cell: Observation of the Dicke Regime in the optical domain, Phys. Rev. A, 1998, V. 57, R3169(R).
[6]   G. Dutier, A. Yarovitski, S. Saltiel, A. Papoyan, D. Sakisyan, D. Bloch and M. Ducloy. Collapse and revival of a Dicke-type coherent narrowing in a sub-micron thick vapor cell transmission spectroscopy, Europhysics Letters, 2003, V. 63, 35-41.
[7]   A. Sagsyan, Y. Pashayan-Leroy, C. Leroy and D. Sarkisyan. Collapse and revival of a Dicke-type coherent narrowing in potassium vapor confined in a nanometric thin cell, Journal of Physics B: Atomic Molecular and Optical Physics, 2016, V. 49, 075001.
[8]   B. Zambon and G. Nienhuis. Reflection and transmission of light by thin vapor layers, Optics Communications, 1997, V. 143, 308-314.
[9]   A.Ch. Izmailov. Limiting Resolution of Linear Absorption Spectroscopy in Thin Gas Cells, Optics and Spectroscopy, 2010, V. 108, 893-898.
[10]  N. Beverini and A.Ch. Izmailov. Sub-Doppler spectroscopy of atoms excited in the regime of Rabi oscillations in a thin gas cell, Optics Communications, 2009, V. 282, 2527-2531.
[11]  F.M. Dickey and T.E. Lizotte. Laser Beam Shaping Applications, 2019, (CRC Press, Taylor@Francis Group).
[12]  P.R. Berman and V.S. Malinovsky. Principles of Laser Spectroscopy and Quantum Optics, 2011 (Princeton University Press).
[13]  A.A. Radzig and B.M. Smirnov. Reference Data on Atoms, Molecules and Ions, 2012 (Springer Berlin Heidelberg).
[14]  F. Riehle. Frequency Standards-Basics and Applications, 2004 (Berlin: Wiley).