Induced resonant absorption of electromagnetic waves by a microparticle

Halina P. Ledneva, Liudmila G. Astafyeva

It is found that, below the first lasing threshold in a spherical microparticle, two steady-state two-mode lasing regimes can occur on morphological resonances of different orders. The bistability region depends on the degree of the spatial overlap of the electromagnetic fields of the resonances and on the absorption of the microparticle material.

Zhenfei Luo, Zhizhan Xu

Э. Г. Сапрыкин, А. А. Черненко

Abstract The physical processes that form the saturated absorption resonance spectra on the atomic transition with level momenta J= 1/2 in the field of unidirectional waves of arbitrary intensities are investigated both analytically and numerically. It is shown that the narrow structures of the nonlinear resonance spectra (resonances of electromagnetic-induced transparency and absorption) and the processes forming them are determined by the direction of the light wave polarizations, degree of openness of the atomic transition, and the saturating wave intensity. The conditions under which the nonlinear resonance is exclusively coherent, due to the magnetic coherence of transition levels, are revealed.

Thomas M. Jenkins

Denis V. Brazhnikov, S M Ignatovich, A. S. Novokreshchenov +1 more

Abstract Electromagnetically induced absorption (EIA) of cesium atoms exposed to counter-propagating light waves with orthogonal linear polarizations is studied. Probe beam transmission through a buffer gas-filled vapor cell is monitored as a function of a static magnetic field applied parallel to the wave vectors. The light waves are tuned to a single dipole transition F g → F e in the D 1 line ( λ = 894.6 nm). The proposed magneto-optical configuration helps overcome a long-standing problem in obtaining high-contrast EIA resonances in conjunction with narrow linewidths. Our experiments demonstrate EIA contrast with respect to a broad Doppler absorption background ( C D ) as high as 1630%. Thus, a high value of C D means that background absorption is almost absent, and the vapor cell transmission profile represents only a single narrow resonance. This result is unique for EIA as well as for electromagnetically induced transparency (EIT) effects, because usually in a resonant medium, narrow EIT or EIA resonances are accompanied by natural-linewidth or other broad spectral features, even in the case of cold atoms. The resonance contrast with respect to the light transmission background ( C back ) is also high enough, reaching 75% in the experiments. The full width at half maximum of the narrowest observed EIA is approximately 0.77 mG (0.7 × 0.77 = 540 Hz in the frequency domain). The considered simple scheme has good prospects for the development of various quantum magneto-optical devices such as optical switches and atomic magnetometers.

A. P. Khapalyuk