Yu. M. Golubev — Page 2

arXiv2004

Controlling a group velocity of light by magnetic field

We have shown that quantum interference in a driven quasi-degenerate two-level atomic system can be controlled by an externally applied magnetic field. We demonstrate that the mechanism of optical control is based on quantum interference, which allows one to implement both electromagnetically induced transparency and electromagnetically induced absorption in one atomic system. Dispersion of such the medium allows one to control group velocity of propagation of light pulses be ultra-slow or superluminal via applied magnetic field.

quant-ph↗

arXiv2004

Polarization squeezing in vertical-cavity surface-emitting lasers

We further elaborate the theory of quantum fluctuations in vertical-cavity surface-emitting lasers (VCSELs), developed in Ref. \cite{Hermier02}. In particular, we introduce the quantum Stokes parameters to describe the quantum self- and cross-correlations between two polarization components of the electromagnetic field generated by this type of lasers. We calculate analytically the fluctuation spectra of these parameters and discuss experiments in which they can be measured. We demonstrate that in certain situations VCSELs can exhibit polarization squeezing over some range of spectral frequencies. This polarization squeezing has its origin in sub-Poissonian pumping statistics of the active laser medium.

quant-ph↗