| Second Generation Organometallic Materials for Non-Linear Optical Application |
26-May-2009 |
18 pages |
| Authors:
Kirk S Schanze; FLORIDA UNIV GAINESVILLE
|
 | The primary focus of this program was to synthesize pi-conjugated oligomers that feature high cross section two-photon absorbing (TPA) chromophores combined with transition metal centers. The TPA chromophores imbue the oligomers with high cross sections for two-photon absorption, whereas the metal centers provide for efficient production of long-lifetime, strongly absorbing triplet excited states. Because of the strong absorption of the triplet excited states, the materials display reverse saturable absorption (RSA). ... |
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| Two-Photon Absorption Measurements: Establishing Reference Standards. |
08 JUN 2007 |
19 pages |
| Authors:
Marek Samoc; Anna Samoc; Paul A. Fleitz; AUSTRALIAN NATIONAL UNIV CANBERRA
|
| Two-Photon Absorption "TPA" is an important phenomenon taking place at high light intensities and consisting in simultaneous absorption of two low energy photons to generate a higher energy excited state of a material. Materials showing efficient two-photon absorption are required for a number of applications including information storage, photonic signal processing, optical power limiting, nonlinear microscopy of biological systems etc. This report contributes to the knowledge of parameters influencing the ... |
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| Accurate Evaluation of Nonlinear Absorption Coefficients in InAs, InSb and HbCdTe Alloys (Postprint) |
06 JUN 2007 |
15 pages |
| Authors:
Shekhar Guha; Zhi G. Yu; SRINIVASAN KRISHNAMURTHY; Leonel P. Gonzales; SRI INTERNATIONAL MENLO PARK CA
|
| We present a full band structure calculation of temperature- and wavelength-dependent two-photon absorption (TPA) coefficients and free carrier absorption (FCA) cross sections in InAs, InSb, and Hg1−xCdxTe alloys. Although the wavelength dependence of the TPA coefficients agrees well with Wherrett expression, the accurately calculated values are smaller by a factor of 1.2 to 2.5. In addition, the TPA coefficient depends sensitively on the photoexcited carrier density in small gap material. ... |
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| Platinum Acetylide Two-Photon Chromophores (Preprint) |
APR 2007 |
62 pages |
| Authors:
Aaron R. Burke; Thomas M. Cooper; Joy E. Rogers; Jonathan E. Slagle; Douglas M. Krein; Benjamin C. Hall; Albert Fratini; Daniel G. McLean; UNIVERSAL ENERGY SYSTEMS INC DAYTON OH HUMAN FACTORS DIV
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| To explore the photophysics of platinum acetylide chromopores having strong two photon cross section, we have investigated the synthesis and spectroscopic characterization of a series of platinum acetylide complexes that feature highly π-conjugated ligands substituted with π-donor or ?acceptor moieties. The molecules (numbered 1-4) considered in the present work are NLO-functionalized analogs of bis(phenylethynyl)bis(bributylphosphine)platinum(II) complexes. Molecule 1 carries two benzothiazolylfluorene and molecule 2 carries two diphenylaminofluorene substituents bound to the ... |
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| Effects of Conjugation in Length and Dimension on Two-Photon Properties of Fluorene-Based Chromophores (Preprint) |
JAN 2007 |
21 pages |
| Authors:
Ruth Pachter; Kiet A. Nguyen; Paul N. Day; Ramamurthi Kannan; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| We report the computed two-photon (TPA) absorption spectra based upon the results obtained from quadratic response time-dependent density functional theory for fluorine-based donor-pi-acceptor molecules. Coulomb attenuated functionals with a long-range exchange contribution are applied to predict TPA excitation energies and cross sections and to account for the observed spectral anomalies. The effects of conjugation and multibranching on the TPA spectra are discussed. |
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| Effects of Solvation on One- and Two-Photon Spectra of Coumarin Derivatives: A Time-Dependent Density Functional Theory Study (Postprint) |
2007 |
13 pages |
| Authors:
Ruth Pachter; Kiet A. Nguyen; Paul N. Day; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| We report one- and two-photon absorption excitation energies and cross sections for a series of 7-aminocoumarins using time-dependent density functional theory with various basis sets and functionals, including exchange-correlation functionals using the Coulomb-attenuating method, to evaluate their performance in the gas phase and in solvents. Except for the results of one functional, the computed one-photon excitation energies and transition dipole moments are in good agreement with experiment. The range of ... |
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| Platinum Acetylide Two-Photon Chromophores (Postprint) |
2007 |
16 pages |
| Authors:
Paul A. Fleitz; Thomas M. Cooper; Joy E. Rogers; Jonathan E. Slagle; Aaron R. Burke; Douglas M. Krein; Benjamin C. Hall; Albert Fratini; Daniel G. McLean; UES INC DAYTON OH
|
| To explore the photophysics of platinum acetylide chromopores having strong two-photon absorption cross-sections, we have investigated the synthesis and spectroscopic characterization of a series of platinum acetylide complexes that feature highly π-conjugated ligands substituted with π-donor or ?acceptor moieties. The molecules (numbered 1-4) considered in the present work are NLO-functionalized analogs of bis(phenylethynyl)bis(bributylphosphine)platinum(II) complexes. Molecule 1 carries two benzothiazolylfluorene and molecule 2 carries two diphenylaminofluorene substituents bound to the central ... |
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| Insight into the Nonlinear Absorbance of Two Related Series of Two-Photon Absorbing Chromophores (Postprint) |
2007 |
11 pages |
| Authors:
Rachel Jakubiak; Loon-Seng Tan; Paul A. Fleitz; Ruth Pachter; Joy E. Rogers; Jonathan E. Slagle; Daniel G. McLean; Richard L. Sutherland; Mark C. Brant; James Heinrichs; Ramamurthi Kannan; UES INC DAYTON OH
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| A comprehensive photophysical study of the linear and nonlinear absorption properties has been carried out on two series of two-photon absorbing dyes to gain insight into how structure-property relationships influence observed nonlinear absorption. The materials studied consist of an electron accepting benzothiazole group connected to an electron donating diphenylamine via a fluorene bridging group. Two series differ from each other by the addition of one phenyl group and for each ... |
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| Effects of Solvation On One- and Two-Photon Spectra of Coumarin Derivatives: A TDDFT Study (Preprint) |
OCT 2006 |
36 pages |
| Authors:
Kiet A. Nguyen; Paul N. Day; Ruth Pachter; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SURVIVABILITY AND SENSOR MATERIALS DIV/HARDENED MATERIALS
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| We report one- (OPA) and two-photon absorption (TPA) excitation energies and cross sections for a series of 7-aminocoumarins using time-dependent density functional theory with various basis sets and functionals, including exchange-correlation functionals using the Coulomb-attenuating method (CAMB3LYP and mCAMB3LYP), to evaluate their performance in gas-phase and in solvents. Except for the CAMB3LYP results , the computed OPA excitation energies and transition dipole moments are in good agreement with experiment. The ... |
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| Combined Nonlinear Effects in Two-Photon Absorption Chromophores at High Intensities (Preprint) |
AUG 2006 |
17 pages |
| Authors:
Richard L. Sutherland; Daniel G. McLean; Mark C. Brant; Joy E. Rogers; Paul A. Fleitz; Augustine M. Urbas; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| Large two-photon and excited state absorption have been reported in donor-acceptor-substituted pi-conjugated molecules. We have performed detailed nonlinear absorption and photophysical measurements on a system of AFX chromophores and calculate the nonlinear transmission based on an effective three-level model. A numerical model that includes far wing linear absorption has been developed and compared with an analytical three-photon absorption model. The models are in accordance and yield excellent agreement with experimental ... |
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| Development of Novel Two-Photon Absorbing Chromophores |
AUG 2006 |
15 pages |
| Authors:
Thomas M. Cooper; James Heinrichs; Loon-Seng Tan; Augustine M. Urbas; Paul A. Fleitz; Joy E. Rogers; Jonathan E. Slagle; Daniel G. McLean; Richard L. Sutherland; Mark Brant; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| There has been much interest in the development of two-photon absorbing materials and many efforts to understand the nonlinear absorption properties of these dyes, but this area is still not well understood. A computational model has been developed in our lab to understand the nanosecond nonlinear absorption properties that incorporate all of the measured one-photon photophysical parameters of a class of materials called AFX. We have investigated the nonlinear and ... |
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| Combined Nonlinear Effects in Two-Photon Absorption Chromophores at High Intensities (Postprint) |
AUG 2006 |
18 pages |
| Authors:
Richard L. Sutherland; Daniel G. McLean; Mark C. Brant; Joy E. Rogers; Paul A. Fleitz; Augustine M. Urbas; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SURVIVABILITY AND SENSOR MATERIALS DIV/HARDENED MATERIALS
|
| Large two-photon and excited state absorption have been reported in donor-acceptor-substituted π-conjugated molecules. We have performed detailed nonlinear absorption and photophysical measurements on a system of AFX chromophores and calculate the nonlinear transmission based on an effective three-level model. A numerical model that includes far wing linear absorption has been developed and compared with an analytical three-photon absorption model. The models are in accordance and yield excellent agreement with experimental ... |
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| Insight into the Nonlinear Absorbance of Two Related Series of Two-Photon Absorbing Chromophores (Preprint) |
JUL 2006 |
30 pages |
| Authors:
Rachel Jakubiak; Loon-Seng Tan; Paul A. Fleitz; Joy E. Rogers; Jonathan E. Slagle; Daniel G. McLean; Richard L. Sutherland; Mark C. Brant; Jim Heinrichs; Ramamurthi Kannan; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| A comprehensive photophysical study has been carried out on two series of two-photon absorbing dyes. Looking at a series of structurally related chromophores provides insight into what controls the linear and nonlinear photophysical properties. These materials consist of an electron withdrawing benzothiazole group connected to a diphenylamine via a fluorene group. Within the series there are one-arm (dipolar), two-arm (quadrupolar), and three-arm (octupolar) versions of each dye. The one photon ... |
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| High Intensity Light Propagation In InAs (Postprint) |
JUN 2006 |
6 pages |
| Authors:
Shekhar Guha; Leo Gonzalez; SRI INTERNATIONAL MENLO PARK CA
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| We present our experimental and theoretical results on nonlinear absorption of light in InAs. The nonlinear variation of output intensity as a function of input intensity and time are calculated by solving four coupled rate equations simultaneously. All required quantities, including two-photon absorption, free-carrier absorption, Auger and radiative recombination lifetimes, and intrinsic carrier densities, have been obtained from the underlying bandstructures. The calculated thickness and energy-dependent output intensities in InAs ... |
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| Organic Glasses and Crystals for Miniature Electro-Optic Devices: Synthesis, Characterization, and Applications |
OCT 2004 |
104 pages |
| Authors:
Felix E. Fernandez; Tanja Timofeeva; Sergey S. Sarkisov; PUERTO RICO UNIV MAYAGUEZ
|
| A high-level computational analysis of two-photon absorbing derivatives of piperidone and cyclohexanone was carried out. Obtained data were compared with the experimental results. The molecular cross-section of the two- photon absorption of these compounds, as high as 3000x10(exp -50) cu cm s/photon at nanosecond pumping, makes then promising nonlinear materials for optical limiting in near-infrared region. They also exhibit an intense two-photon exciting fluorescence, of the same order as that ... |
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| New Generation Photonics Materials: Design, Development, Characterization and Applications |
01 MAY 2004 |
10 pages |
| Authors:
Paras N. Prasad; STATE UNIV OF NEW YORK AT BUFFALO INST FOR LASERS PHOTONICS AND BIOPHOTONICS
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| A significant amount of research was accomplished in the design, development, characterization and applications of two types of photonic materials: Multiphoton absorbing materials and hybrid nanocomposites for photorefractivity. We synthesized a new class of two-photon dyes which are pyridinum-based inner salts (covalently bonded) and achieved two- photon lasing. Another accomplishment was to produce two-photon active liquid dyes with enhanced number density. In collaboration with AFRL at Dayton who synthesized 1, ... |
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| Photorefractive Fibers |
16 OCT 2003 |
10 pages |
| Authors:
Mark G. Kuzyk; WASHINGTON STATE UNIV PULLMAN DEPT OF PHYSICS
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| We have discovered that photo-isomerization in the simple DR1 molecule can be used for limiting in regions where the material is transparent. We have used this effect for various demonstrations of light control and beam shaping - prerequisites for making optical limiters. We have also developed a theory of what makes the maximum nonlinear response and have applied it to two photon absorption to determine The accomplishments of our research ... |
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| New Generation Photonics Materials: Design, Development, Characterization and Applications |
19 SEP 2003 |
14 pages |
| Authors:
Paras N. Prasad; Guang S. He; STATE UNIV OF NEW YORK AT BUFFALO INST FOR LASERS PHOTONICS AND BIOPHOTONICS
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| Recent successes in developing two-photon absorption (2PA) materials and applications have now created significant interest in exploring three-photon absorption (3PA) based novel optical materials and new applications. 3PA-based techniques may exhibit two major advantages: (1) much longer IR wavelengths (1. 2-1.7 micronm) can be used, and (2) much better beam confinement (resolution) can be achieved owing to the cubic dependence of nonlinear absorption on the local intensity of the excitation ... |
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| Multi-Layer Worm Disk with Parallel Recording and Read-Out for High Capacity Storage |
APR 2003 |
81 pages |
| Authors:
D. Dvornikov; E. Walker; P. Rentzepis; S. Esener; CALL RECALL INC SAN DIEGO CA
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| Technology has been developed to enable recording and reading of optical disks having many layers. The approach selected relies on recording bits in a volume by using single beam two-photon recording. A volumetric bit is written in the volume of a molded photochromic dispersed organic polymer only at spatial locations where the recording beam has sufficient photon energy. Data recording is based on two-photon absorption, by which one molecule is ... |
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| Approaches to Advanced Materials for Photorefractive Applications and Radiation Hardening |
01 JUN 2002 |
39 pages |
| Authors:
Seth R. Marder; ARIZONA UNIV TUCSON DEPT OF CHEMISTRY
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| We have made considerable advances in the development of optical- limiting systems based upon two-photon absorption processes. To accomplish this, it has been essential to develop an understanding of basic structure-property relationships for conjugated organic materials. To this end, we have investigated a range of phenylene-vinylene-based materials substituted with various combinations of donor and acceptor moieties. We now have a more thorough understanding of how to design materials with very ... |
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| Emissivity Engineered Infrared Materials, 3-Dimensionally Patterned by Two Photon Lithography |
04 JAN 2001 |
40 pages |
| Authors:
Bruce Dunn; Eli Yablonovitch; CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| The objective of this program is to make infrared pigments whose emissivity can be controlled. The principal approach we have taken is to make 3- dimensionally microstructured metallodielectric materials by two-photon lithography in photoresist, and back-filling with metals. In this program we demonstrated that we can quickly and efficiency fabricate 3<1 microstructures in photoresist using a diode pumped Ti-sapphire modelocked laser in combination with a mechanical scanning technology. Metal back-filling ... |
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| Re-Writable Two-Photon Three Dimensional Optical Memory |
JAN 2001 |
11 pages |
| Authors:
Paras N. Prasad; STATE UNIV OF NEW YORK AT ALBANY RESEARCH FOUNDATION
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| Using a polymer block, doped with a highly efficient two-photon dye, we have achieved a high density data-storage with gray-scale control in multiple planes as stacked Compact Disks (CDs) at a separation of 10 micron m. The absorption and fluorescence of the dye at the written spot shift to a longer wavelength, permitting an easy fluorescence mode readout with a linear excitation using an inexpensive laser source. The storage capacity ... |
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| DURIP97 Instrumentation for Characterization of Two-Photon Absorbing Organic Materials |
05 JUN 1998 |
11 pages |
| Authors:
Seith R. Marder; Joseph W. Perry; CALIFORNIA INST OF TECHNOLOGY PASADENABECKMAN INST
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| DURIP funds were used to purchase a Spex Model FL112 High Performance Research Grade Fluorimeter and a Nd:YAG-pumped nanosecond Optical Parametric Oscillator Laser System with tunability from 440 nm - 1800 nm. This equipment was used to measure the two-photon absorption spectra for a variety of molecules from different classes and identify promising candidate molecules to meet DoD requirements for a variety of applications. A strategy for the design of ... |
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| Two-Photon Spectroscopy Beyond the Standard Quantum Limit |
03 AUG 95 |
10 pages |
| Authors:
Daniel J. Gauthier; DUKE UNIV DURHAM NC DEPT OF PHYSICS
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| The development of ultrasensitive detectors and ultralow noise lasers for two photon spectroscopy is described. |
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| Two-Photon Induced Fluorescence and Lasing of Microdroplets |
AUG 95 |
49 pages |
| Authors:
James B. Gillespie; Richard K. Chang; Alfred S. Kwok; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM
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| The feasibility of using two photon induced fluorescence of amino acids is examined for its potential as a detection technique for biological aerosols. The research was motivated by the problem of spectral discrimination encountered in fluorescence applications. Two separate experiments were performed: (1) two-photon induced fluorescence of the three aromatic amino acids and (2) two-photon pumped lasing in spherical droplets doped with rhodomine 6g dye. It was found in the ... |
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| Optical Switching for a Nonlinear Directional Coupler Including the Effects of Two Photon Absorption, |
APR 1992 |
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| Authors:
M. J. Potasek; J. M. Fang; COLUMBIA UNIV NEW YORK DEPT OF APPLIED PHYSICS AND NUCLEAR ENGINEERING
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 | All-optical switching is of growing interest. However, complete all-optical switching in materials such as semiconductors has proved difficult. If the nonlinear index of refraction is utilized, there is also strong two photon absorption (TPA). It has been shown that the typical soliton solutions are not valid in the presence of TPA. Therefore traditional soliton switching is degraded. However we present a new coupled mode analysis which incorporates TPA and find ... |
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| Experimental and Theoretical Investigations of Two-Photon and Free Carrier Absorption in a GaAs/A1GaAs Quantum Well Waveguide, |
APR 1992 |
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| Authors:
F. R. Laughton; J. H. Marsh; J. S. Roberts; GLASGOW UNIV (UNITED KINGDOM)
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| There have been many studies of two-photon absorption (TPA) in semiconductors. In calculating the TPA coefficient, beta, the effect of free carrier absorption (FCA) has often been neglected. However, it is relatively straightforward to include this by means of an intuitive theoretical model. The model's use can be demonstrated in evaluating B from nonlinear absorption experiments carried out in GaAs/AlGaAs Multiple Quantum Well (MQW) waveguides using a Nd:YAG laser. When ... |
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| Two-Photon Absorption Characterization of HgCdTe |
30 JUL 90 |
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| Authors:
Chris L. Littler; NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS
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| Magneto-Optical measurements of Hg1-xCdxTe alloys have provided a new means of studying impurities and defects in this important II-VI material. Two- photon magnetoabsorption (TMPA) has been used to accurately determine the temperature dependence of the energy gap of various HgCdTe alloys, revealing behavior that deviates from currently accepted models. In addition, magnetooptical techniques have been used to detect the presence of both shallow and deep impurities/defects and accurately determine their ... |
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| Photon-Gated Persistent Spectral Hole-Burning |
11 SEP 89 |
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| Authors:
W. E. Moerner; IBM ALMADEN RESEARCH CENTER SAN JOSE CA
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| This article reviews recent progress in the area of photon gated persistent spectral hole burning, in which one photon selects absorbers in an inhomogeneously broadened line and a second gating photon of a different wavelength completes the excitation necessary to produce a spectral hole. This phenomenon provides a crucial threshold in the hole formation process, allowing reading with the first wavelength alone to be nondestructive. Examples of photo gating in ... |
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| Two Photon Absorption Characterization |
15 MAY 89 |
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| Authors:
Chris Littler; NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS
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| Magnetooptical measurements of Hg(1-x)Cd(x)Te alloys have provided a new means of studying impurities and defects in this important II-VI material. Two-photon magnetoabsorption (TMPA) has been used to accurately determine the temperature dependence of the energy gap of various HgCdTe alloys, revealing behavior that deviates from currently accepted models. In addition, magnetooptical techniques have been used to detect the presence of both shallow and deep impurities/defects and accurately determine their activation ... |
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| Multiphoton Detection Techniques for F and F2 |
28 APR 89 |
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| Authors:
G. W. Faris; M. J. Dyer; D. L. Huestis; SRI INTERNATIONAL MENLO PARK CA
|
| During the last year we have been performing experiments that will lead to the development of quantitative remote diagnostics for atomic and molecular fluorine, using ultraviolet multiphoton excitation followed by the detection of fluorescence or ionization. This report, describes the first demonstration of resonant multiphoton excitation of molecular fluorine and the construction of a new apparatus for high-sensitivity detection of atomic fluorine using two-photon absorption of 170-nm radiation from a ... |
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| Two-Photon Absorption Characterization of HgCdTe |
JAN 89 |
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| Authors:
David G. Seiler; NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS
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| Magneto-Optical measurements of Hg(1-x)Cd(X)Te alloys have provided a new means of studying impurities and defects in this important II-VI material. Two-photon magnetoabsorption (TMPA) has been used to accurately determine the temperature dependence of the energy gap of various HgCdTe alloys, revealing behavior that deviates from currently accepted models. In addition, magneto- optical techniques have been used to detect the presence of both shallow and deep impurities/defects and accurately determine their ... |
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| Two-Photon Absorption Characterization |
JAN 89 |
|
| Authors:
Chris L. Littler; David G. Seiler; NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS
|
| Magneto-Optical measurements of Hg(1-X)Cd(X)Te alloys have provided a new means of studying impurities and defects in this important II-VI material. Two-photon magnetoabsorption (TMPA) has been used to accurately determine the temperature dependence of the energy gap of various HgCdTe alloys, revealing behavior that deviates from currently accepted models. In addition, magneto- optical techniques have been used to detect the presence of both shallow and deep impurities/defects and accurately determine their ... |
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| Two Photon Characterization |
DEC 88 |
|
| Authors:
David G. Seiler; NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS
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| Magneto-Optical studies of HgCdTe have provided a rich new group of spectroscopies for studying defects and impurities in narrow band semiconductors such as HgCdTe. Keywords: Mercury cadmium telluride; Group II IV compounds; Two photon absorption; Defect characterization; Magneto optical measurements; Two photon spectroscopy; Narrow band gap semiconductors. (JHD) |
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| Two-Photon Absorption Characterization |
JUL 88 |
|
| Authors:
David G. Seiler; NORTH TEXAS STATE UNIV DENTON CENTER FOR APPLIED QUANTUM ELECTRONICS
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| Magneto-Optical studies of HgCdTe have provided a rich new group of spectroscopies for studying defects and impurities in narrow band semiconductors such as HgCdTe. Keywords: Defect characterization, Magneto optical measurements, Two photon spectroscopy, Narrow band gap semiconductors, II-VI Compounds, Mercury cadmium tellurides. (mjm) |
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| Two-Photon Detection Techniques for Atomic Fluorine |
04 MAR 87 |
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| Authors:
William K. Bischel; Gregory C. Herring; SRI INTERNATIONAL MENLO PARK CA
|
| During the last year, we focused on experiments that will lead to a quantitative and remote diagnostic for atomic fluorine using multiphoton excitation followed by the detection of fluorescence or ionization. Three experimental investigations are summarized in this report. First, we describe an experiment to generate the sixth anti-Strokes (AS) wave at 170 nm from a tunable 285-nm beam for use in a two-photon absorption experiment. Second, we report the ... |
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| Study of VUV Generation by Coherent Resonant Frequency Mixing in Metal Vapors |
24 APR 86 |
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| Authors:
Jean-Claude Diels; NORTH TEXAS STATE UNIV DENTON CENTER FOR APPLIED QUANTUM ELECTRONICS
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| The properties of multiphoton resonances (two, four, or more) are exploited to enhance up frequency conversion rates. Simultaneously, the property of reversibility of coherent interaction is used to minimize the resonant losses (two-photon, four-photon absorption). A source of tunable, near bandwidth limited pulses, of more than a millijoule energy per pulse has been developed. A new scheme of computer controlled data acquisition made it possible to analyze, for the first ... |
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| Calculation of Single- and Double-Photon Free-Free Cross Sections for Electrons Scattered from HE, C, N, NE and AR |
FEB 86 |
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| Authors:
Edward J. Robinson; NEW YORK UNIV NY DEPT OF PHYSICS
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| Calculations of cross sections for the free-free absorption of radiation by electrons scattered from atoms are reported. The results apply in the limit where theory is valid, and are obtained in the context of a realistic independent particle atomic model, which facilitates numerical solutions for both perturbed and unperturbed wave functions. Both one photon and two photon absorptions are analyzed, the latter in a mixed gauge representation. The method is ... |
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| Nonlinear Optical Interactions in Semiconductors |
10 DEC 85 |
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| Authors:
Michael M. Salour; TACAN AEROSPACE CORP CARLSBAD CA
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| The optical pumping technique in GaAs has led to the development of a novel and highly sensitive optical temperature sensor. Completed is the experiment on two photon optical pumping in ZnO. An external cavity semiconductor laser involving ZnO as a gain medium was demonstrated under two- photon excitation. This laser should have a major impact on the development of tunable blue-green radiation for submarine communication. Completed is a paper on ... |
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| On the Dynamics of Molecular Two-Photon Excitation through Real Intermediate States |
84 |
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| Authors:
L. Bigio; E. R. Grant; CORNELL UNIV ITHACA NY
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| New results from our laboratory on the two-photon absorption spectroscopy and photodissociation dynamics of NO2 are examined in the light of a simple nonperturbative theory for the time evolution of the intermediate state in a three-level system. Experiments on NO2 show effects distinct to two-photon excitation, evident spectroscopically in intense bent-to-linear origins and dynamically in unique patterns of energy disposal in two-photon photodissociation. We trace these effects to intramolecular relaxation ... |
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| High Rydberg States of Jet-Cooled Toluene Observed by Ultraviolet Two- Photon Absorption Spectroscopy: Ultrafast Radiationless Decay and Pseudo-Jahn Teller Effects |
84 |
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| Authors:
R. L. Whetten; K. Fu; E. R. Grant; CORNELL UNIV ITHACA NY BAKER LAB
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| Three new Rydberg series converging to the first ionization potential of toluene are identified by the method of ultraviolet two-photon absorption in a supersonic jet. No Rydberg series converging to the near-degenerate second ionization potenital are found, a result analogous to that known for the valence systems of benzenoid molecules. The vibronic spectrum of the toluenecation is discussed in light of this result, and the failure to observe a distinct ... |
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| Multiwavelength-Selective Ionization of Organic Compounds in an Ion Mobility Spectrometer |
MAY 1983 |
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| Authors:
David M. Lubman; Mel N. Kronick; QUANTA-RAY INC MOUNTAIN VIEW CA
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| Phase Conjugation in Biharmonically Pumped Two-Photon Resonant Systems |
17 MAR 1982 |
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| Authors:
Govind P. Agrawal; CITY COLL NEW YORK DEPT OF PHYSICS
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| Two-Photon Spectroscopy in HF |
30 APR 1981 |
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| Authors:
Gary M. Carter; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| Theory of Two-Photon Double-Beam Optical Bistability |
19 FEB 1981 |
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| Authors:
G. P. Agrawal; C. Flytzanis; CITY COLL NEW YORK
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| Two-Photon Absorption in Crystals with the Presence of Electric Field, |
14 NOV 1980 |
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| Authors:
S. Kh. S'ynov; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
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| A Study of TPF Structure for Multiple Overlapping of Picosecond Laser Light Pulses. |
1980 |
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| Authors:
D. D. Venable; HAMPTON INST VA DEPT OF PHYSICS
|
| A systematic study has been conducted to characterize the multiple overlapping of closely spaced laser pulses in a two-photon fluorescence (TPF) cell. Parametric analysis of the autocorrelation function for the amplitude of a closely spaced laser pulse train containing n-pulses has reproduced TPF spectra experimentally observed with a low-light-level electro-optics detecting system. The effects of one- and two-photon absorption has been analyzed. Theoretical predictions have been presented for peak to ... |
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| Laser Excitation of Inner-Shell Atomic States by Multiquantum Processes. |
31 OCT 1979 |
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| Authors:
Charles K. Rhodes; R. Thomas Hawkins; ILLINOIS UNIV AT CHICAGO CIRCLE DEPT OF PHYSICS
|
| Multiquantum ultraviolet processes utilizing the available ultrahigh spectral brightness rare gas halogen technology can be used to generate inversion densities 10 to the 15th power/cu cm in the 10-20 eV range. On the basis of current experimental findings we conclude that these nonlinear methods of excitation can be successfully extrapolated to excitations in the 20-50 eV range, the region of excited atomic inner-shell configurations. (Author) |
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| Study of Two-Photon Absorption and Amplification Processes in Gases. |
01 SEP 1979 |
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| Authors:
Lorenzo M. Narducci; DREXEL UNIV PHILADELPHIA PA DEPT OF PHYSICS AND ATMOSPHERIC SCIENCES
|
| This report summarizes our theoretical and experimental findings. It is divided into 8 sections. Section 1 contains a general description of the problem and a summary of the main results. Section 2 contains the theory of two-photon amplification. Section 3 details the requirements for the selection of an appropriate active medium. Section 4 describes the pumping requirements and the handling and preparation of the vapor cell. Section 5 contains a ... |
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| Study of Collisional Redistribution Using Two-Photon Absorption with a Nearly Resonant Intermediate State, |
SEP 1979 |
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| Authors:
P. R. Berman ; P. F. Liao ; J. E. Bjorkholm; NEW YORK UNIV N Y DEPT OF PHYSICS
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| We report studies of collision-induced features of the 3S(1/2) yields 3P(1/2) yields 4D(3/2) two-photon absorption in atomic sodium vapor undergoing collisionss with several rare gas perturbers. The results yield the collisional redistribution function which describes the nonresonant excitation of the 3P(1/2) intermediate state. Good agreement with theory is obtained only if effects of 3P(1/2) in equilibrium with 3P(3/2) state-changing collisions are included in the calculations. Results are used to obtain ... |
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Reports by Keyword(s)
*TWO PHOTON ABSORPTION
