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Title: Multiphoton contributions to far infrared generation in optically pumped deuterium oxide

Abstract

Far Infrared (FIR) emission at 66 and 50 ..mu..m in D/sub 2/O vapor, optically pumped with a CO/sub 2/ TEA laser, is shown to constitute a stimulated Raman process associated with each wave within a system of four molecular vibrational-rotational levels. A propagation model, based on a semiclassical, quasistatic (t much greater than T/sub 2/), density matrix analysis, is constructed and applied to the system. The model is generalized to include one-, two-, and three-wave interactions among three near-reasonant waves of arbitrary intensity in a variety of four-level system configurations. Level degeneracies and relative field polarizations are treated explicitly. New insignts are obtained regarding the AC Stark shifted gain spectra of each wave in the presence of the others. Parameters for the model are derived from calculations and measurements, the latter including a survey of infrared self pressure broadening coefficients in D/sub 2/O and an analysis of FIR self-absorption. A detailed characterization of the FIR evolution in a single-pass amplifier configuration reveals distinct threshold and saturation features as well as pump absorption behavior indicative of its nonlinear conversion of FIR radiation. Measurements of the FIR absorption in D/sub 2/O establishes that the emitted wavelengths are detuned by a degree commensuratemore » with the measured pump detuning, again substantiating a stimulated Raman process. Agreement between the model calculations and the empirical data is shown with respect both to FIR temporal behavior and to 66 ..mu..m pulse energy vs D/sub 2/O pressure and pump intensity. Explicit account is taken of inhomogeneous broadening of the pump transition at lower D/sub 2/O pressures.« less

Authors:
Publication Date:
Research Org.:
Illinois Univ., Urbana (USA)
OSTI Identifier:
6212200
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; HEAVY WATER; STIMULATED EMISSION; CARBON DIOXIDE LASERS; ENERGY ABSORPTION; FAR INFRARED RADIATION; MATHEMATICAL MODELS; OPTICAL PUMPING; RAMAN EFFECT; STARK EFFECT; WATER VAPOR; ABSORPTION; ELECTROMAGNETIC RADIATION; EMISSION; ENERGY-LEVEL TRANSITIONS; FLUIDS; GAS LASERS; GASES; HYDROGEN COMPOUNDS; INFRARED RADIATION; LASERS; OXYGEN COMPOUNDS; PUMPING; RADIATIONS; VAPORS; WATER; 640302* - Atomic, Molecular & Chemical Physics- Atomic & Molecular Properties & Theory

Citation Formats

Petuchowski, S J. Multiphoton contributions to far infrared generation in optically pumped deuterium oxide. United States: N. p., 1979. Web.
Petuchowski, S J. Multiphoton contributions to far infrared generation in optically pumped deuterium oxide. United States.
Petuchowski, S J. Mon . "Multiphoton contributions to far infrared generation in optically pumped deuterium oxide". United States.
@article{osti_6212200,
title = {Multiphoton contributions to far infrared generation in optically pumped deuterium oxide},
author = {Petuchowski, S J},
abstractNote = {Far Infrared (FIR) emission at 66 and 50 ..mu..m in D/sub 2/O vapor, optically pumped with a CO/sub 2/ TEA laser, is shown to constitute a stimulated Raman process associated with each wave within a system of four molecular vibrational-rotational levels. A propagation model, based on a semiclassical, quasistatic (t much greater than T/sub 2/), density matrix analysis, is constructed and applied to the system. The model is generalized to include one-, two-, and three-wave interactions among three near-reasonant waves of arbitrary intensity in a variety of four-level system configurations. Level degeneracies and relative field polarizations are treated explicitly. New insignts are obtained regarding the AC Stark shifted gain spectra of each wave in the presence of the others. Parameters for the model are derived from calculations and measurements, the latter including a survey of infrared self pressure broadening coefficients in D/sub 2/O and an analysis of FIR self-absorption. A detailed characterization of the FIR evolution in a single-pass amplifier configuration reveals distinct threshold and saturation features as well as pump absorption behavior indicative of its nonlinear conversion of FIR radiation. Measurements of the FIR absorption in D/sub 2/O establishes that the emitted wavelengths are detuned by a degree commensurate with the measured pump detuning, again substantiating a stimulated Raman process. Agreement between the model calculations and the empirical data is shown with respect both to FIR temporal behavior and to 66 ..mu..m pulse energy vs D/sub 2/O pressure and pump intensity. Explicit account is taken of inhomogeneous broadening of the pump transition at lower D/sub 2/O pressures.},
doi = {},
url = {https://www.osti.gov/biblio/6212200}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1979},
month = {1}
}

Thesis/Dissertation:
Other availability
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