A large volume (30 cm 3 ) of dense (up to 10 15 cm -3 ) Rb vapour was pumped optically by a high-power laser diode array. The conditions for the propagation of high-power broad-band optical pump radiation through an optically dense medium were examined. A spectroscopic method was developed for determination of the polarisation of Rb. The dependence of the polarisation of Rb on its vapour pressure was investigated at buffer gas pressures of 1, 8, and 13 bar. Under optimal conditions a 15-W diode laser made it possible to polarise at least 10 18 of 3 He atoms per second during collisions between Rb and 3 He atoms, sufficient for the creation of an efficient neutron polariser.A large volume (30 cm 3 ) of dense (up to 10 15 cm -3 ) Rb vapour was pumped optically by a high-power laser diode array. The conditions for the propagation of high-power broad-band optical pump radiation through an optically dense medium were examined. A spectroscopic method was developed for determination of the polarisation of Rb. The dependence of the polarisation of Rb on its vapour pressure was investigated at buffer gas pressures of 1, 8, and 13 bar. Under optimal conditions a 15-W diode laser made it possible to polarise at least 10 18 of 3 He atoms per second during collisions between Rb and 3 He atoms, sufficient for the creation of an efficient neutron polariser.

Quantum ElectronicsJan 31, 20003 citations

Second order interference in two photon absorption

M. W. Hamilton

Journal of Modern OpticsSep 1, 19961 citation

Level degeneracy in the operation of a Zeeman ionic laser

K B Kurlaev, David A. Shapiro

The Coulomb broadening of a magneto-optical resonance of degenerate two-level ions in the field of a standing wave is calculated. Under the conditions of linear polarisation of this wave, of the normal Zeeman effect, and of weak saturation, the broadening is described by familiar expressions for multistage and two-photon resonances in separate three-level subsystems and the coefficients in these expressions depend on the angular momenta. The profile of a nonlinear resonance in the dependence of the output power of a single-frequency Zeeman ionic laser on the applied magnetic field consists of a narrow central interference peak, a wide diffusion part, and Lorentzian wings. It is shown that, in the case of a broad lower active level, the J → J+1 transitions are more favourable for the observation of a two-photon resonance and the relative amplitude of the resonance is not less than 2/7.The Coulomb broadening of a magneto-optical resonance of degenerate two-level ions in the field of a standing wave is calculated. Under the conditions of linear polarisation of this wave, of the normal Zeeman effect, and of weak saturation, the broadening is described by familiar expressions for multistage and two-photon resonances in separate three-level subsystems and the coefficients in these expressions depend on the angular momenta. The profile of a nonlinear resonance in the dependence of the output power of a single-frequency Zeeman ionic laser on the applied magnetic field consists of a narrow central interference peak, a wide diffusion part, and Lorentzian wings. It is shown that, in the case of a broad lower active level, the J → J+1 transitions are more favourable for the observation of a two-photon resonance and the relative amplitude of the resonance is not less than 2/7.

Quantum ElectronicsAug 31, 19970 citations

Polarization dependence of two-photon absorption during a collision (A)

William A. Molander, Michael Scott Belsley, Keith R. Burnett

Journal of the Optical Society of America AJan 1, 19830 citations

Two-photon ionisation: Interference and population trapping

PAUL M. RADMORE, P. L. Knight

Physics Letters AMay 1, 198441 citations

Two-photon excitation of Ho3+ in the Ca F2 , Sr F2 , and Cd F2 lattices

D. Narayana Rao, Jagdish Prasad, Paras N. Prasad

The observation of two-photon absorption by a very efficient up-converted emission is reported for ${\mathrm{Ho}}^{3+}$ in Ca ${\mathrm{F}}_{2}$ , Sr ${\mathrm{F}}_{2}$ , and Cd ${\mathrm{F}}_{2}$ with both cw- and pulse-laser excitations. The two-photon excitation spectra are found to be highly structured and consist of two bands: The band $A$ is excited by the dye-laser photons of frequencies 15 400-15 700 ${\mathrm{cm}}^{\ensuremath{-}1}$: The band $B$ is excited by the dye-laser photons of frequencies 15 800-16 400 ${\mathrm{cm}}^{\ensuremath{-}1}$. No one-photon absorption is observed for ${\mathrm{Ho}}^{3+}$ in the above lattices at twice these frequencies. Studies of concentration dependence, temperature dependence, and dependence on the pulse repetition rate are used for the assignment of the band. The investigation shows that the two bands $A$ and $B$ arise from two different modes of two-photon excitation. The band $A$ is assigned to arise from a sequential (stepwise) two-photon excitation $^{5}I_{8}\ensuremath{\rightarrow}^{5}F_{5}\ensuremath{\rightarrow}^{5}D_{2}$. The band $B$ is assigned to arise from the direct two-photon absorption $^{5}I_{8}\ensuremath{\rightarrow}^{3}L_{8}$. Our results are in agreement with the prediction of the Judd-Ofelt theory of lanthanide transition intensities.The observation of two-photon absorption by a very efficient up-converted emission is reported for ${\mathrm{Ho}}^{3+}$ in Ca${\mathrm{F}}_{2}$, Sr${\mathrm{F}}_{2}$, and Cd${\mathrm{F}}_{2}$ with both cw- and pulse-laser excitations. The two-photon excitation spectra are found to be highly structured and consist of two bands: The band $A$ is excited by the dye-laser photons of frequencies 15 400-15 700 ${\mathrm{cm}}^{\ensuremath{-}1}$: The band $B$ is excited by the dye-laser photons of frequencies 15 800-16 400 ${\mathrm{cm}}^{\ensuremath{-}1}$. No one-photon absorption is observed for ${\mathrm{Ho}}^{3+}$ in the above lattices at twice these frequencies. Studies of concentration dependence, temperature dependence, and dependence on the pulse repetition rate are used for the assignment of the band. The investigation shows that the two bands $A$ and $B$ arise from two different modes of two-photon excitation. The band $A$ is assigned to arise from a sequential (stepwise) two-photon excitation $^{5}I_{8}\ensuremath{\rightarrow}^{5}F_{5}\ensuremath{\rightarrow}^{5}D_{2}$. The band $B$ is assigned to arise from the direct two-photon absorption $^{5}I_{8}\ensuremath{\rightarrow}^{3}L_{8}$. Our results are in agreement with the prediction of the Judd-Ofelt theory of lanthanide transition intensities.

Physical review. B, Condensed matterJul 1, 198322 citations

The observation of two-photon absorption by a very efficient up-converted emission is reported for

{\mathrm{Ho}}^{3+}

in Ca

{\mathrm{F}}_{2}

, Sr

{\mathrm{F}}_{2}

, and Cd

{\mathrm{F}}_{2}

with both cw- and pulse-laser excitations. The two-photon excitation spectra are found to be highly structured and consist of two bands: The band

A

is excited by the dye-laser photons of frequencies 15 400-15 700 ${\mathrm{cm}}^{\ensuremath{-}1}$: The band

B

is excited by the dye-laser photons of frequencies 15 800-16 400 ${\mathrm{cm}}^{\ensuremath{-}1}$. No one-photon absorption is observed for

{\mathrm{Ho}}^{3+}

in the above lattices at twice these frequencies. Studies of concentration dependence, temperature dependence, and dependence on the pulse repetition rate are used for the assignment of the band. The investigation shows that the two bands

A

and

B

arise from two different modes of two-photon excitation. The band

A

is assigned to arise from a sequential (stepwise) two-photon excitation $^{5}I_{8}\ensuremath{\rightarrow}^{5}F_{5}\ensuremath{\rightarrow}^{5}D_{2}$. The band

B

is assigned to arise from the direct two-photon absorption $^{5}I_{8}\ensuremath{\rightarrow}^{3}L_{8}$. Our results are in agreement with the prediction of the Judd-Ofelt theory of lanthanide transition intensities.