Molecular Collision Kernels by Stark Sublevel Photon Echoes: Radiator Reorientation and Population Transfer.

Radiator reorientation kernels are measured in Stark-tunable infrared transitions of 13CH3F. The dominant (ΔM = 1) kernel is obtained by a scale transformation from the shape of a two-pulse photon-echo intensity versus Stark voltage curve, at fixed large echo time delay. The quantum-mechanical transport equation in the presence of coherence M transfer and a dc electric field is reviewed, and the applications of photon echoes in a tunable Stark field to measure reorientation collision kernels are discussed.Radiator reorientation kernels are measured in Stark-tunable infrared transitions of 13CH3F. The dominant (ΔM = 1) kernel is obtained by a scale transformation from the shape of a two-pulse photon-echo intensity versus Stark voltage curve, at fixed large echo time delay. The quantum-mechanical transport equation in the presence of coherence M transfer and a dc electric field is reviewed, and the applications of photon echoes in a tunable Stark field to measure reorientation collision kernels are discussed.

Journal of the Optical Society of America BApr 1, 19865 citations

Molecular collision studies with Stark-decelerated beams

Gerard Meijer

Bulletin of the American Physical SocietyMar 10, 20080 citations

DISCRETE TRANSFORM OF MOLECULAR M CHANGING KERNELS BY STARK SUBLEVEL ECHOES

Jinju Liang, L. A. Spinelli, J. E. Thomas +2 more

We report the investigation of molecular M changing kernels using new Stark sublevel photon echo techniques to obtain, for the first time, the entire distribution of discrete M transfer rates. The method exploits the analogy between velocity space, where inhomogeneous broadening is due to Doppler frequency shifts, and M space where an artificial inhomogeneity can be created with a small Stark field. In the presence of the Stark field, random collision induced coherence transfer between M sublevels of an infrared transition of moderate J leads to Stark field dependant degradation of the molecular macroscopic polarization during the echo dephasing-rephasing process. The effects of inelastic (J changing) collisions and elastic velocity changing collisions which are field independent can be eliminated by measuring the ratio of the echo signals with the field on and off as a fuction of either echo time delay or Stark field. The nonexponential decay curve which is obtained is related to the M changing collisions kernel by discrete transformation with the frequency components $\\nu{_{s}}\\Delta $M, where $\\Delta M$ is an integer and $\\nu_{s}$ is the Stark shift for unit M. In the experiment, the $(V=0, J=4, K=3) \\longrightarrow (v_{3}=1, J=5, K=3)$ transition in $CH_{3}P$ is studied. Acoustooptic (A/0) intensity modulation of 9P32 c.w. $CO_{2}$ laser radiation is used for input pulse generation. A novel digital oscillator driver is employed which has no RF leakage, so that A/0 rejected ratios are scattered light limited at $^{-}106:1$ . Preliminary results yield echo signals with very high signal to background ratio and show completely new nonexponential behavior of the echo decay curve. Applications of both two and three pulse (stimulated) sublevel experiments will be described."We report the investigation of molecular M changing kernels using new Stark sublevel photon echo techniques to obtain, for the first time, the entire distribution of discrete M transfer rates. The method exploits the analogy between velocity space, where inhomogeneous broadening is due to Doppler frequency shifts, and M space where an artificial inhomogeneity can be created with a small Stark field. In the presence of the Stark field, random collision induced coherence transfer between M sublevels of an infrared transition of moderate J leads to Stark field dependant degradation of the molecular macroscopic polarization during the echo dephasing-rephasing process. The effects of inelastic (J changing) collisions and elastic velocity changing collisions which are field independent can be eliminated by measuring the ratio of the echo signals with the field on and off as a fuction of either echo time delay or Stark field. The nonexponential decay curve which is obtained is related to the M changing collisions kernel by discrete transformation with the frequency components $\\nu{_{s}}\\Delta $M, where $\\Delta M$ is an integer and $\\nu_{s}$ is the Stark shift for unit M. In the experiment, the $(V=0, J=4, K=3) \\longrightarrow (v_{3}=1, J=5, K=3)$ transition in $CH_{3}P$ is studied. Acoustooptic (A/0) intensity modulation of 9P32 c.w. $CO_{2}$ laser radiation is used for input pulse generation. A novel digital oscillator driver is employed which has no RF leakage, so that A/0 rejected ratios are scattered light limited at $^{-}106:1$. Preliminary results yield echo signals with very high signal to background ratio and show completely new nonexponential behavior of the echo decay curve. Applications of both two and three pulse (stimulated) sublevel experiments will be described."

Jan 1, 19850 citations

Collisional orientation of atoms and molecules in a resonance light field

Anatolii M. Shalagin

Sep 1, 19792 citations

Radiator reorientation kernels by tunable energy compensation

John E. Thomas, J. M. Liang, Ramachandra Rao Dasari

We describe a new Stark sublevel photon echo technique for measuring fluctuations in macroscopic coherences. This idea is applied to the Stark tunable infrared (λ = 9 μm) R(4, 3, V3 = 0 → 1) transition of 13CH3F to measure, for the first time, the radiator reorientation velocity changing kernels WΔ M (Δv) which describe the rates (per unit velocity) at which the radiator orientation M changes by an amount ΔM accompanied by a velocity change Δv.1 In the experiments, two pulse photon echoes are obtained using a laser field polarized along an applied weak de Stark field ( z ^ direction) which shifts each M transition by Mvs (Hz).We describe a new Stark sublevel photon echo technique for measuring fluctuations in macroscopic coherences. This idea is applied to the Stark tunable infrared (λ = 9 μm) R(4, 3, V3 = 0 → 1) transition of 13CH3F to measure, for the first time, the radiator reorientation velocity changing kernels WΔ M (Δv) which describe the rates (per unit velocity) at which the radiator orientation M changes by an amount ΔM accompanied by a velocity change Δv.1 In the experiments, two pulse photon echoes are obtained using a laser field polarized along an applied weak de Stark field ( z ^ direction) which shifts each M transition by Mvs (Hz).

Annual Meeting Optical Society of AmericaJan 1, 19860 citations

\\Delta M

is an integer and

\\nu_{s}

is the Stark shift for unit M. In the experiment, the

(V=0, J=4, K=3) \\longrightarrow (v_{3}=1, J=5, K=3)

transition in

CH_{3}P

is studied. Acoustooptic (A/0) intensity modulation of 9P32 c.w.

CO_{2}

laser radiation is used for input pulse generation. A novel digital oscillator driver is employed which has no RF leakage, so that A/0 rejected ratios are scattered light limited at

^{-}106:1

. Preliminary results yield echo signals with very high signal to background ratio and show completely new nonexponential behavior of the echo decay curve. Applications of both two and three pulse (stimulated) sublevel experiments will be described."