Erasure of data stored by use of photon echoes has been investigated as a function of data writing time and data storage time. The results clarify the requirements on laser phase and frequency stability for performing photon-echo data erasure. The analysis of phase and frequency stability of a light source by the photon-echo erasure process is illustrated. A theoretical analysis emphasizing the physical processes that affect the erasure efficiency as well as an extensive discussion of possible error sources are given. Finally, an approach to bit-selective photon-echo data erasure that is insensitive to laser phase and frequency fluctuations is suggested.Erasure of data stored by use of photon echoes has been investigated as a function of data writing time and data storage time. The results clarify the requirements on laser phase and frequency stability for performing photon-echo data erasure. The analysis of phase and frequency stability of a light source by the photon-echo erasure process is illustrated. A theoretical analysis emphasizing the physical processes that affect the erasure efficiency as well as an extensive discussion of possible error sources are given. Finally, an approach to bit-selective photon-echo data erasure that is insensitive to laser phase and frequency fluctuations is suggested.

Journal of the Optical Society of America BSep 1, 199618 citations

On the natural fluctuations of the intensity and frequency of a two-mode laser

Yu. I. Zaǐtsev

Radiophysics and Quantum ElectronicsJun 1, 19701 citation

Direct measurement of the Aharonov-Casher phase and tensor Stark polarizability using a calcium atomic polarization interferometer

Shinya Yanagimachi, M. Kajiro, 守町屋 +1 more

An atomic polarizing white-color interferometer composed of the wave packets in the $m=+1$ and $m=\ensuremath{-}1$ states of the excited ${}^{3}{P}_{1}$ state of Ca, has been developed using a thermal atomic beam excited by a pair of two resonant lights at two separate zones under a homogeneous magnetic field. The interferometer generated the Ramsey fringes as a detuning of the rf frequency between two resonant lights from the Zeeman-frequency shift, while it generates white-color interference fringes as a detuning of laser frequency. The interferometer was used for the direct and short-time measurement of the Aharonov-Casher phase by removing the main part of dc Stark phase shift and without the influence of the frequency fluctuation of a laser. The measured dependence of the Aharonov-Casher phase on the electric field agreed with the predicted one within a relative uncertainty of 2.9%. The tensor polarizability in the ${}^{3}{P}_{1}$ state was determined to be ${\ensuremath{\alpha}}_{2}=2.623\ifmmode\pm\else\textpm\fi{}0.015 \mathrm{k}\mathrm{H}\mathrm{z}/(\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m}{)}^{2}$ from the frequency shift between the $m=+1$ and $m=\ensuremath{-}1$ states.An atomic polarizing white-color interferometer composed of the wave packets in the $m=+1$ and $m=\ensuremath{-}1$ states of the excited ${}^{3}{P}_{1}$ state of Ca, has been developed using a thermal atomic beam excited by a pair of two resonant lights at two separate zones under a homogeneous magnetic field. The interferometer generated the Ramsey fringes as a detuning of the rf frequency between two resonant lights from the Zeeman-frequency shift, while it generates white-color interference fringes as a detuning of laser frequency. The interferometer was used for the direct and short-time measurement of the Aharonov-Casher phase by removing the main part of dc Stark phase shift and without the influence of the frequency fluctuation of a laser. The measured dependence of the Aharonov-Casher phase on the electric field agreed with the predicted one within a relative uncertainty of 2.9%. The tensor polarizability in the ${}^{3}{P}_{1}$ state was determined to be ${\ensuremath{\alpha}}_{2}=2.623\ifmmode\pm\else\textpm\fi{}0.015 \mathrm{k}\mathrm{H}\mathrm{z}/(\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m}{)}^{2}$ from the frequency shift between the $m=+1$ and $m=\ensuremath{-}1$ states.

Physical Review AMar 14, 200228 citations

Theory of intensity and phase fluctuations of a homogeneously broadened laser

Hermann Haken

The European Physical Journal ASep 1, 1966179 citations

Collisional dephasing and the reduction of laser phase-noise to amplitude-noise conversion in a resonant atomic vapor

John G. Coffer, M. Anderson, James C. Camparo

When resonant laser light passes through a vapor, the laser's intrinsic phase fluctuations induce random variations in the atomic coherence, which in turn give rise to fluctuations in the medium's absorption cross section. Hence, laser phase modulation noise (PM) is converted to transmitted laser intensity (i.e., amplitude) modulation noise (AM). Here, we consider the influence of collisional dephasing on the PM-to-AM conversion process. Specifically, we measure the relative intensity noise of a diode laser beam, resonant with the Rb ${D}_{1}$ transition at 794.7 nm, after it has passed through a ${\mathrm{Rb}}^{87}/{\mathrm{N}}_{2}$ vapor as a function of nitrogen number density. Our results demonstrate that when collisional dephasing is very rapid, the spectral density of cross-section fluctuations is reduced, so that there is a significant decrease in the efficiency of PM-to-AM conversion at low Fourier frequencies. These results imply that, in general, when laser PM-to-AM conversion is the dominant noise process, pressure broadening can actually increase spectroscopic sensitivity.When resonant laser light passes through a vapor, the laser's intrinsic phase fluctuations induce random variations in the atomic coherence, which in turn give rise to fluctuations in the medium's absorption cross section. Hence, laser phase modulation noise (PM) is converted to transmitted laser intensity (i.e., amplitude) modulation noise (AM). Here, we consider the influence of collisional dephasing on the PM-to-AM conversion process. Specifically, we measure the relative intensity noise of a diode laser beam, resonant with the Rb ${D}_{1}$ transition at 794.7 nm, after it has passed through a ${\mathrm{Rb}}^{87}/{\mathrm{N}}_{2}$ vapor as a function of nitrogen number density. Our results demonstrate that when collisional dephasing is very rapid, the spectral density of cross-section fluctuations is reduced, so that there is a significant decrease in the efficiency of PM-to-AM conversion at low Fourier frequencies. These results imply that, in general, when laser PM-to-AM conversion is the dominant noise process, pressure broadening can actually increase spectroscopic sensitivity.

Physical Review AFeb 6, 200240 citations

Effect of the quantum fluctuations of radiation on optical frequency measurements

Michael Z. Smirnov

Optics and SpectroscopyJul 1, 19900 citations

An atomic polarizing white-color interferometer composed of the wave packets in the

m=+1

and $m=\ensuremath{-}1$ states of the excited

{}^{3}{P}_{1}

state of Ca, has been developed using a thermal atomic beam excited by a pair of two resonant lights at two separate zones under a homogeneous magnetic field. The interferometer generated the Ramsey fringes as a detuning of the rf frequency between two resonant lights from the Zeeman-frequency shift, while it generates white-color interference fringes as a detuning of laser frequency. The interferometer was used for the direct and short-time measurement of the Aharonov-Casher phase by removing the main part of dc Stark phase shift and without the influence of the frequency fluctuation of a laser. The measured dependence of the Aharonov-Casher phase on the electric field agreed with the predicted one within a relative uncertainty of 2.9%. The tensor polarizability in the

{}^{3}{P}_{1}

state was determined to be ${\ensuremath{\alpha}}_{2}=2.623\ifmmode\pm\else\textpm\fi{}0.015 \mathrm{k}\mathrm{H}\mathrm{z}/(\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m}{)}^{2}$ from the frequency shift between the

m=+1

and $m=\ensuremath{-}1$ states.

{D}_{1}

transition at 794.7 nm, after it has passed through a

{\mathrm{Rb}}^{87}/{\mathrm{N}}_{2}

vapor as a function of nitrogen number density. Our results demonstrate that when collisional dephasing is very rapid, the spectral density of cross-section fluctuations is reduced, so that there is a significant decrease in the efficiency of PM-to-AM conversion at low Fourier frequencies. These results imply that, in general, when laser PM-to-AM conversion is the dominant noise process, pressure broadening can actually increase spectroscopic sensitivity.