Cross relaxation effects in ruby maser crystals are treated by introduction of a cross relaxation probability in the rate equations. Detailed solutions have been obtained for several specific processes and compared to recent experiments. It is shown that cross relaxation can improve maser performance even in the absence of impurity doping. Pulse experiments at 0.06 and 0.14% chromium ion concentrations in a ruby traveling wave maser are interpreted in terms of a five-spin process in addition to a four-spin process.Cross relaxation effects in ruby maser crystals are treated by introduction of a cross relaxation probability in the rate equations. Detailed solutions have been obtained for several specific processes and compared to recent experiments. It is shown that cross relaxation can improve maser performance even in the absence of impurity doping. Pulse experiments at 0.06 and 0.14% chromium ion concentrations in a ruby traveling wave maser are interpreted in terms of a five-spin process in addition to a four-spin process.

Physical ReviewFeb 15, 19618 citations

Relaxation Effects

WORLD SCIENTIFIC eBooksOct 1, 20080 citations

Collisional relaxation of excited-state Zeeman coherences in atomic ytterbium vapor

Arjun G. Yodh, J. E. Golub, THOMAS W. MOSSBERG

We present the results of an experiment designed to probe the collision-induced relaxation of excited-state Yb Zeeman coherences. Our experiment is sensitive not only to the depolarization-type relaxation mechanisms often observed in optical-pumping experiments, but also to the effects of collisionally induced velocity changes. Our measurements were performed in the 6s6p ${\mathrm{}}^{3}$ ${P}_{1}$ excited state of the even (I=0) isotopes of gas-phase atomic Yb by means of a trilevel photon-echo technique. Depolarization rates, velocity-change spectra, and total scattering cross sections of Yb-He (Yb-Ar) collisions were measured (deduced). Both rank-1 and rank-2 spherical tensor components of the $^{3}\mathrm{P}_{1}$ state play a role in our experiment, and our results represent averages of potentially different relaxation rates attributable to these quantities. Comparison of our results with rank-0 results obtained elsewhere reveals interesting similarities as well as differences.We present the results of an experiment designed to probe the collision-induced relaxation of excited-state Yb Zeeman coherences. Our experiment is sensitive not only to the depolarization-type relaxation mechanisms often observed in optical-pumping experiments, but also to the effects of collisionally induced velocity changes. Our measurements were performed in the 6s6p ${\mathrm{}}^{3}$${P}_{1}$ excited state of the even (I=0) isotopes of gas-phase atomic Yb by means of a trilevel photon-echo technique. Depolarization rates, velocity-change spectra, and total scattering cross sections of Yb-He (Yb-Ar) collisions were measured (deduced). Both rank-1 and rank-2 spherical tensor components of the $^{3}\mathrm{P}_{1}$ state play a role in our experiment, and our results represent averages of potentially different relaxation rates attributable to these quantities. Comparison of our results with rank-0 results obtained elsewhere reveals interesting similarities as well as differences.

Physical Review AAug 1, 198519 citations

General Considerations on Relaxation

Pure and applied physicsJan 1, 19590 citations

Investigation on the methods to extend the transverse relaxation time of polarized alkali atoms

Yang-Ying Fu, Jie Yuan

In order to improve the sensitivity of radio-frequency atomic magnetometer, two methods to extend the transverse relaxation time of polarized alkali atoms are investigated. One way is the application of a non-relaxing coating, another way is the introduction of buffer gas into cell. A theory relaxation model is built, and the dependences of transverse relaxation time on buffer gas pressure, laser power, cell temperature, and magnetic-field gradient are obtained. The measurements of transverse relaxation time are carried out in a cesium atomic radio-frequency magnetometer. The optical experiment conditions which yield the highest sensitivity are determined in experiments. Experiments results indicate that the optimal pressure for neon is 200 Torr. The experimental results are in agreement with the theoretical ones. An ultimate sensitivity of 100 fT/Hz1/2 of the cesium atomic radio-frequency magnetometer has been achieved. This study helps further optimization of the cell performance and the sensitivity of radio-frequency atomic magnetometer.In order to improve the sensitivity of radio-frequency atomic magnetometer, two methods to extend the transverse relaxation time of polarized alkali atoms are investigated. One way is the application of a non-relaxing coating, another way is the introduction of buffer gas into cell. A theory relaxation model is built, and the dependences of transverse relaxation time on buffer gas pressure, laser power, cell temperature, and magnetic-field gradient are obtained. The measurements of transverse relaxation time are carried out in a cesium atomic radio-frequency magnetometer. The optical experiment conditions which yield the highest sensitivity are determined in experiments. Experiments results indicate that the optimal pressure for neon is 200 Torr. The experimental results are in agreement with the theoretical ones. An ultimate sensitivity of 100 fT/Hz1/2 of the cesium atomic radio-frequency magnetometer has been achieved. This study helps further optimization of the cell performance and the sensitivity of radio-frequency atomic magnetometer.

National Conference on Laser Technology and Optoelectronics (LTO)May 17, 20190 citations

{\mathrm{}}^{3}

{P}_{1}

excited state of the even (I=0) isotopes of gas-phase atomic Yb by means of a trilevel photon-echo technique. Depolarization rates, velocity-change spectra, and total scattering cross sections of Yb-He (Yb-Ar) collisions were measured (deduced). Both rank-1 and rank-2 spherical tensor components of the

^{3}\mathrm{P}_{1}

state play a role in our experiment, and our results represent averages of potentially different relaxation rates attributable to these quantities. Comparison of our results with rank-0 results obtained elsewhere reveals interesting similarities as well as differences.