Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Distinguishing molecular-reorientation gratings from thermal gratings by a time-delayed method

Zuhe Yu, Xin Mi, Qian Jiang, Peixian Ye, Panming Fu

Published Feb 1, 1988• 10 citations
Publisher

Abstract

We demonstrate a novel time-delayed method that employs the partially coherent properties of pump beams to distinguish molecular-reorientation gratings from thermal gratings. An extension of this method to the case of population grating is pointed out.
DOI
10.1364/ol.13.000117

Related papers

Fourth-order coherence-function theory of laser-induced molecular reorientational grating and population grating

Panming Fu, Zuhe Yu, Xin Mi +1 more

We have employed fourth-order coherence-function theory to study the influence of the partial-coherence properties of pump beams on the laser-induced gratings. First, we examine the formation of molecular reorientational grating. The different roles of phase fluctuation and amplitude fluctuation have been pointed out. A time-delayed method has been proposed to distinguish molecular reorientational grating from thermal grating. We then apply the fourth-order theory to study the Bragg reflection from a population grating. We obtain an analytic solution which enables us to make an extensive investigation on the temporal behaviour of the Bragg reflection signal. This study is especially helpful for elucidating the generation mechanism of population grating.

Journal de physique•Jan 1, 1987•15 citations

Time-delayed laser-induced double gratings

Xin Mi, Zuhe Yu, Qian Jiang +2 more

We have employed chaotic and phase-diffusion models to study the effect of laser coherence on time-delayed laser-induced double gratings (TDLIDG). It is found that, although the temporal behavior of the four-wave mixing signal depends on the stochastic properties of the lasers and the relaxation time of the grating, the modulation of the signal is always damped out when the relative time delay between two pump beams is much longer than the laser coherence time. We performed a TDLIDG experiment mediated by thermal effects to study the temporal behavior of the modulation, and we obtained the frequency difference between two light beams with an accuracy limited by the laser linewidth. We also studied the influence of the phase change in the optical path on TDLIDG.

Journal of the Optical Society of America B•Apr 1, 1993•19 citations

Proposed picosecond excited-state measurement method using a tunable-laser-induced grating

Anthony E.. Siegman

This letter analyzes a suggested technique for studying excited atomic or molecular states on a picosecond to subpicosecond time scale by using tunable laser beams, without requiring ultrafast laser pulses or optical detectors. In the proposed technique the frequency transform of the impulse response of an excited state is determined by measuring the diffraction of a cw probe laser beam from a moving excited-state grating induced by two intersecting tunable excitation beams, as the frequency difference between the two cw excitation beams is varied.

Applied Physics Letters•Jan 1, 1977•37 citations

Theoretical study of the suppression of thermal background in the Raman-enhanced nondegenerate four-wave-mixing spectrum by a time-delayed method

Panming Fu, Zuhe Yu, Xin Mi +2 more

We have studied theoretically the dependence of the Raman-enhanced nondegenerate four-wave-mixing (RENFWM) spectrum on the relative time delay between two pump beams \ensuremath{\tau} when a thermal effect exists in the sample. Using the chaotic model for the incident laser beams, we give the conditions that the thermal background can be eliminated completely when the relative time delay is much longer than the laser coherence time. In this limit, the theoretical RENFWM spectra show the normal asymmetry due to the interference between the Raman-resonant term and the nonresonant background originating solely from the molecular-reorientational grating. We then turn our attention to the dependence of the RENFWM signal intensity on the relative time delay when the laser frequencies are fixed. Our results indicate that RENFWM is asymmetric about \ensuremath{\tau}=0 and the maximum of the RENFWM signal does not occur at \ensuremath{\tau}=0. When the beating frequency between the pump beam and the probe beam is off resonant from the Raman mode, the RENFWM signal exhibits damping oscillation as the time delay increases. We also show that the temporal behavior of the RENFWM signal is drastically different if the laser sources are described by a phase-diffusion model. The different roles of the phase fluctuation and the amplitude fluctuation can be understood in the time domain.

Physical Review A•Aug 1, 1992•21 citations

Formation of dynamic gratings by coherent interaction of atomic states and measurement of transverse relaxation time

M. Szczurek, M. Kuśnierz

Optics Communications•Dec 1, 1989•7 citations

Time-of-flight resolved transmission-grating diffraction of molecular beams

W. Sch�llkopf, R. E. Grisenti, J. P. Toennies

The European Physical Journal D•Jan 1, 2004•11 citations
We have employed fourth-order coherence-function theory to study the influence of the partial-coherence properties of pump beams on the laser-induced gratings. First, we examine the formation of molecular reorientational grating. The different roles of phase fluctuation and amplitude fluctuation have been pointed out. A time-delayed method has been proposed to distinguish molecular reorientational grating from thermal grating. We then apply the fourth-order theory to study the Bragg reflection from a population grating. We obtain an analytic solution which enables us to make an extensive investigation on the temporal behaviour of the Bragg reflection signal. This study is especially helpful for elucidating the generation mechanism of population grating.
We have employed chaotic and phase-diffusion models to study the effect of laser coherence on time-delayed laser-induced double gratings (TDLIDG). It is found that, although the temporal behavior of the four-wave mixing signal depends on the stochastic properties of the lasers and the relaxation time of the grating, the modulation of the signal is always damped out when the relative time delay between two pump beams is much longer than the laser coherence time. We performed a TDLIDG experiment mediated by thermal effects to study the temporal behavior of the modulation, and we obtained the frequency difference between two light beams with an accuracy limited by the laser linewidth. We also studied the influence of the phase change in the optical path on TDLIDG.
This letter analyzes a suggested technique for studying excited atomic or molecular states on a picosecond to subpicosecond time scale by using tunable laser beams, without requiring ultrafast laser pulses or optical detectors. In the proposed technique the frequency transform of the impulse response of an excited state is determined by measuring the diffraction of a cw probe laser beam from a moving excited-state grating induced by two intersecting tunable excitation beams, as the frequency difference between the two cw excitation beams is varied.
We have studied theoretically the dependence of the Raman-enhanced nondegenerate four-wave-mixing (RENFWM) spectrum on the relative time delay between two pump beams \ensuremath{\tau} when a thermal effect exists in the sample. Using the chaotic model for the incident laser beams, we give the conditions that the thermal background can be eliminated completely when the relative time delay is much longer than the laser coherence time. In this limit, the theoretical RENFWM spectra show the normal asymmetry due to the interference between the Raman-resonant term and the nonresonant background originating solely from the molecular-reorientational grating. We then turn our attention to the dependence of the RENFWM signal intensity on the relative time delay when the laser frequencies are fixed. Our results indicate that RENFWM is asymmetric about \ensuremath{\tau}=0 and the maximum of the RENFWM signal does not occur at \ensuremath{\tau}=0. When the beating frequency between the pump beam and the probe beam is off resonant from the Raman mode, the RENFWM signal exhibits damping oscillation as the time delay increases. We also show that the temporal behavior of the RENFWM signal is drastically different if the laser sources are described by a phase-diffusion model. The different roles of the phase fluctuation and the amplitude fluctuation can be understood in the time domain.