Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (1170)
- Electrical and Computer Engineering (902)
- Electromagnetics and Photonics (603)
- Electrical and Electronics (255)
- Atomic, Molecular and Optical Physics (228)
-
- Computer Engineering (189)
- Other Electrical and Computer Engineering (173)
- Systems and Communications (159)
- Quantum Physics (134)
- Materials Science and Engineering (118)
- Condensed Matter Physics (117)
- Other Physics (111)
- Engineering Physics (103)
- Chemistry (82)
- Plasma and Beam Physics (81)
- Signal Processing (75)
- Nanoscience and Nanotechnology (72)
- Semiconductor and Optical Materials (69)
- Oceanography and Atmospheric Sciences and Meteorology (63)
- Life Sciences (62)
- Mechanical Engineering (50)
- Biomedical Engineering and Bioengineering (48)
- Computer Sciences (47)
- Atmospheric Sciences (46)
- Medicine and Health Sciences (38)
- Other Engineering (37)
- Applied Mathematics (33)
- Institution
-
- University of Central Florida (355)
- Air Force Institute of Technology (349)
- University of Dayton (249)
- Technological University Dublin (165)
- Chapman University (95)
-
- Old Dominion University (95)
- City University of New York (CUNY) (84)
- University of Arkansas, Fayetteville (68)
- California Polytechnic State University, San Luis Obispo (58)
- University of New Orleans (54)
- University of New Mexico (52)
- Washington University in St. Louis (43)
- Michigan Technological University (36)
- Claremont Colleges (31)
- Rose-Hulman Institute of Technology (28)
- Munster Technological University (25)
- University of Malaya (24)
- University of Nebraska - Lincoln (24)
- University of South Florida (24)
- Portland State University (23)
- Purdue University (23)
- University at Albany, State University of New York (22)
- University of Texas at El Paso (21)
- Clemson University (19)
- Louisiana State University (19)
- University of Kentucky (17)
- University of Alabama in Huntsville (16)
- University of South Carolina (15)
- Missouri University of Science and Technology (14)
- Utah State University (12)
- Keyword
-
- Optics (109)
- Holography (59)
- Nonlinear optics (45)
- Laser (41)
- Photonics (40)
-
- Adaptive optics (39)
- Lasers (38)
- Spectroscopy (36)
- Interferometry (27)
- Photopolymer (27)
- Plasmonics (26)
- Physics (24)
- Photopolymers (23)
- Thin films (22)
- Atmospheric turbulence (21)
- Pure sciences (21)
- Remote sensing (21)
- #ctisr (20)
- Polarization (20)
- Refractive index (20)
- Diffraction (19)
- Imaging (18)
- Openaire (18)
- Imaging systems (17)
- Scattering (17)
- Semiconductor lasers (17)
- Infrared (16)
- Metamaterials (16)
- Photoluminescence (16)
- Semiconductors (16)
- Publication Year
- Publication
-
- Electronic Theses and Dissertations (291)
- Theses and Dissertations (235)
- Electrical and Computer Engineering Faculty Publications (189)
- Faculty Publications (124)
- Articles (93)
-
- Mathematics, Physics, and Computer Science Faculty Articles and Research (85)
- Conference Papers (58)
- Electrical Engineering Faculty Publications (54)
- Dissertations, Theses, and Capstone Projects (46)
- Physics Faculty Publications (45)
- Electronic Theses and Dissertations, 2020-2023 (44)
- Electro-Optics and Photonics Faculty Publications (41)
- Graduate Theses and Dissertations (40)
- Optical Science and Engineering ETDs (38)
- Physics (31)
- Graduate Theses - Physics and Optical Engineering (28)
- USF Tampa Graduate Theses and Dissertations (24)
- All HMC Faculty Publications and Research (23)
- McKelvey School of Engineering Graduate Student Theses & Dissertations (22)
- Electrical & Computer Engineering Faculty Publications (21)
- Electrical & Systems Engineering Publications and Presentations (21)
- Publications and Research (21)
- AFIT Patents (20)
- Open Access Theses & Dissertations (20)
- Cappa Publications (19)
- Electrical & Computer Engineering Theses & Dissertations (19)
- Legacy Theses & Dissertations (2009 - 2024) (19)
- Dissertations and Theses (18)
- Masters Theses (18)
- Physics Theses & Dissertations (18)
- Publication Type
- File Type
Articles 2101 - 2130 of 2339
Full-Text Articles in Optics
Two-Level Atom In An Optical Parametric Oscillator: Spectra Of Transmitted And Fluorescent Fields In The Weak Driving Field Limit, James P. Clemens, Perry R. Rice, Pranaw Kumar Rungta, Robert J. Brecha
Two-Level Atom In An Optical Parametric Oscillator: Spectra Of Transmitted And Fluorescent Fields In The Weak Driving Field Limit, James P. Clemens, Perry R. Rice, Pranaw Kumar Rungta, Robert J. Brecha
Physics Faculty Publications
We consider the interaction of a two-level atom inside an optical parametric oscillator. In the weak-driving-field limit, we essentially have an atom-cavity system driven by the occasional pair of correlated photons, or weakly squeezed light. We find that we may have holes, or dips, in the spectrum of the fluorescent and transmitted light. This occurs even in the strong-coupling limit when we find holes in the vacuum-Rabi doublet. Also, spectra with a subnatural linewidth may occur. These effects disappear for larger driving fields, unlike the spectral narrowing obtained in resonance fluorescence in a squeezed vacuum; here it is important that …
Quantum Computation Through Entangling Single Photons In Multipath Interferometers, John C. Howell, John A. Yeazell
Quantum Computation Through Entangling Single Photons In Multipath Interferometers, John C. Howell, John A. Yeazell
Mathematics, Physics, and Computer Science Faculty Articles and Research
Single-photon interferometry has been used to simulate quantum computations. Its use has been limited to studying few-bit applications due to rapid growth in physical size with numbers of bits. We propose a hybrid approach that employs n photons, each having L degrees of freedom yielding Ln basis states. The photons are entangled via a quantum nondemolition measurement. This approach introduces the essential element of quantum computing, that is, entanglement into the interferometry. Using these techniques, we demonstrate a controlled-NOT gate and a Grover's search circuit. These ideas are also applicable to the study of nonlocal correlations in many dimensions.
Entangling Macroscopic Quantum States, John C. Howell, John A. Yeazell
Entangling Macroscopic Quantum States, John C. Howell, John A. Yeazell
Mathematics, Physics, and Computer Science Faculty Articles and Research
Spatial entanglements of macroscopic quantum systems are proposed. The which-path uncertainty of a single photon passing through a beam splitter is transformed into the which-path uncertainty of two macroscopic fields via two quantum nondemolition measurements. The macroscopic fields are nonlocally correlated.
Rotation-Invariant Synthetic Discriminant Function Filter For Pattern Recognition, Vahid R. Riasati, Partha P. Banerjee, Mustafa A. G. Abushagur, Kenneth B. Howell
Rotation-Invariant Synthetic Discriminant Function Filter For Pattern Recognition, Vahid R. Riasati, Partha P. Banerjee, Mustafa A. G. Abushagur, Kenneth B. Howell
Electrical and Computer Engineering Faculty Publications
The ring synthetic discriminant function (RSDF) filter for rotation-invariant response is discussed for pattern recognition. This method uses one half of a slice of the Fourier transform of the object to generate the transfer function of the filter. This is accomplished by rotating the one half of a slice in the Fourier domain through 2π rad about the zero-frequency point of the Fourier plane. This filter has the advantage of always matching at least one half of a slice of the Fourier transform of any rotation of the image. An analytical discussion of the filter construction and correlation results are …
Reducing The Complexity Of Linear Optics Quantum Circuits, John C. Howell, John A. Yeazell
Reducing The Complexity Of Linear Optics Quantum Circuits, John C. Howell, John A. Yeazell
Mathematics, Physics, and Computer Science Faculty Articles and Research
Integrated optical elements can simplify the linear optics used to simulate quantum circuits. These linear optical simulations of quantum circuits have been developed primarily in terms of the free space optics associated with single-photon interferometry. For an L-bit simulation the number of required free-space optical elements is ∝2L if 50/50 beam splitters are used. The implementation (construction and alignment) of these circuits with these free-space elements is nontrivial. On the other hand, for the cases presented in this paper in which linear integrated optics (e.g., 2L×2L fiber couplers) are used, the number of optical devices does …
An Optical Coherence Microscope For 3-Dimensional Imaging In Developmental Biology, Barbara M. Hoeling, Andrew D. Fernandez, Richard C. Haskell, Eric Huang, Whittier R. Myers, Daniel C. Petersen, Sharon E. Ungersma, Ruye Wang, Mary E. Williams, Scott E. Fraser
An Optical Coherence Microscope For 3-Dimensional Imaging In Developmental Biology, Barbara M. Hoeling, Andrew D. Fernandez, Richard C. Haskell, Eric Huang, Whittier R. Myers, Daniel C. Petersen, Sharon E. Ungersma, Ruye Wang, Mary E. Williams, Scott E. Fraser
All HMC Faculty Publications and Research
An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument.
Investigation Of Laser Beam Combining And Cleanup Via Seeded Stimulated Brillouin Scattering In Multimode Optical Fibers, Bryan J. Choi
Investigation Of Laser Beam Combining And Cleanup Via Seeded Stimulated Brillouin Scattering In Multimode Optical Fibers, Bryan J. Choi
Theses and Dissertations
The purpose of this thesis research was to determine if stimulated Brillouin scattering amplification in multimode optical fibers would exhibit the same laser beam combining and clean-up properties exhibited by SBS oscillation, and to characterize the Brillouin amplification process in a multimode optical fiber. Beam combining in multimode fibers via SBS is being considered as a method of combining low power laser beams into a single beam having higher power and superior spatial coherence for applications such as electro-optic countermeasures. Experimental results demonstrate seeding a 9.5 mm fiber significantly reduced the pump power required to initiate SBS. An amplified Stokes …
Multi-Conjugate Adaptive Optics For The Compensation Of Amplitude And Phase Distortions, Peter N. Crabtree
Multi-Conjugate Adaptive Optics For The Compensation Of Amplitude And Phase Distortions, Peter N. Crabtree
Theses and Dissertations
Two deformable mirrors (DMs) with finite conjugate ranges are investigated for compensating amplitude and phase distortions due to laser propagation through turbulent atmospheres. Simulations are performed based on Adaptive Optics (AO) for an Airborne Laser-type scenario. The Strehl ratio, the number of branch points in DM controls, and the number of iterations to convergence are used as figures of merit to evaluate performance of the Sequential Generalized Projection Algorithm that generates mirror commands. The results are ensemble averages over 32 realizations of the scintillated test fields for each value of the Rytov parameter within the test scenario. The Gaussian beam …
Active Multispectral Bidirectional Reflectance Distribution Function Measurement System, Mark J. Proctor
Active Multispectral Bidirectional Reflectance Distribution Function Measurement System, Mark J. Proctor
Theses and Dissertations
Today's highly technical battlefield environment dictates the need for a method of standoff target identification, which reduces risk to personnel and equipment. It is widely known that a given material will react differently to incident radiation than a dissimilar material. Certain materials may respond specularly while others tend to be diffuse. By measuring these responses, materials can be identified by comparison with a known database. One method of building such a database for target recognition is by employing an active multi spectral bidirectional reflectance distribution function (BRDF) measurement system. In the following text, such a system is developed and tested …
Optical Metrology Of Adaptive Membrane Mirrors, John W. Wagner
Optical Metrology Of Adaptive Membrane Mirrors, John W. Wagner
Theses and Dissertations
Current space-based imaging platforms are significantly constrained in both size and weight by the launch vehicle. Increased payload size and weight results in increased cost and a decrease in launch responsiveness. The USAF Scientific Advisory Board (SAB) identified "Large lightweight structures for optics and antennas" as a revolutionary primary technology to be developed for the Air Force of the 21st Century. A membrane primary mirror in a space-based imaging system has the ability to overcome current payload constraints and meet evolutionary needs of the future. The challenge of membrane optics in space is the process of implementing adaptive optics technology …
Characterization Of Poly-Si Thin Films Deposited By Magnetron Sputtering Onto Ni Prelayers, Elena A. Guliants, Wayne A. Anderson
Characterization Of Poly-Si Thin Films Deposited By Magnetron Sputtering Onto Ni Prelayers, Elena A. Guliants, Wayne A. Anderson
Electrical and Computer Engineering Faculty Publications
A method of producing a polycrystalline silicon thin film on a foreign substrate without subsequent annealing has been developed. Thermally evaporated 5–100 nm thick Nifilms served as prelayers for magnetron sputtered Si thin films. A continuous film was obtained as a result of metal induced growth of polysilicon during low temperature (below 600 °C) deposition. The film uniformity is promising for large area device applications. The influence of the Ni prelayer thickness on the grain size of thus obtained films was investigated. Atomic force microscopy and cross-sectional scanning electron microscopy studies revealed features in the 150–600 nm size range while …
Optical Performance Of Grazing Incidence X-Ray / Euv Telescopes For Space Science Applications, Patrick Louis Thompson
Optical Performance Of Grazing Incidence X-Ray / Euv Telescopes For Space Science Applications, Patrick Louis Thompson
Retrospective Theses and Dissertations
The science and technology of X-rays has only been part of human achievement for the past 100 years, while the study of image formation in general has endured for as long as 1000 years. The ability to conceive, design, and fabricate X-ray imagers, moreover, has existed for only the past 70 years, and X-ray astronomical telescopes have been in use for a mere 35 years. Considering that aplanatic, normal incidence telescope designs required more than 400 years to perfect, it is most interesting to note that the development of ‘aplanatic’ grazing incidence telescopes has taken only about 40 years. In …
Development Of Multiple Channels Edf Lasers, Muhammad Zamzuri Abdul Kadir
Development Of Multiple Channels Edf Lasers, Muhammad Zamzuri Abdul Kadir
Student Works (2000-2009)
This thesis presents the research work carried out on the development and analysis of single wavelength EDFL and multiple wavelength EDFL. Two types of single wavelength EDF ring laser were studied namely a fixed signal wavelength system and a tuneable signal wavelength system. However, emphasis was given to the first case. The analyses made, were based on the following parameters: pump and signal stability, pump power, reflectivity, EDF length and cavity loss. The influence of each cavity component such as isolator, polarisation controller, attenuator and tuneable filter were also investigated and reported here. Only one type of multiple wavelength EDFL …
Digital Holography And Application In Laser Metrology, Thian Khok Yong
Digital Holography And Application In Laser Metrology, Thian Khok Yong
Student Works (2000-2009)
A digital holography system has been developed in this study. The object is recorded and the hologram is stored electronically with a charged-couple-device (CCD) camera without any focusing optics. The reconstruction of the digitally sampled hologram is done numerically with a computer. The algorithm and software for numerical reconstruction, which consists in a numerical realization of the Fresnel-Kirchhoff diffraction integral, are designed and implemented with twodimensional and three-dimensional simple objects. The characteristics of the system have been studied. For the CCD camera (768x494 pixels) been used with spatial resolution of about I 00 lines/mm, the angle between reference and object …
Erbium-Ytterbium Codoped Fiber Amplifiers, Wai Yee Chan
Erbium-Ytterbium Codoped Fiber Amplifiers, Wai Yee Chan
Student Works (2000-2009)
The amplification characteristics of an Erbium/Ytterbium codoped fiber amplifier(EYDFA) pumped in both the 800nm and 980nm pump bands is reported. With -3m long Er-Yb fiber, the 813nm pumped-EYDFA shows small-signal gain exceeding 20dB over a 20nm bandwidth in the l.Sµm region where the peak gain of 38.4dB is achieved at 1535nm. A low noise figure of ~3.6d8 is also achieved at 1550nm. However, it is found that 980nm pumpedEYDF A suffers lower gain due to the effect of nonsaturable absorption by Yb³⁺ ions which causes high pump poWer loss, thus degrades the signal amplification in Er³⁺ system. Compared to the …
Optimisation Of Transverse Arc Array Laser, Albert Kok Foo Ng
Optimisation Of Transverse Arc Array Laser, Albert Kok Foo Ng
Student Works (2000-2009)
A novel discharge scheme is proposed for the pumping of short wavelen,gth lasers. This scheme had been tested to produce fast current pulse and a 5 kA current in 60 nsec is obtained. Lasing action has been observed by using nitrogen gas. The laser line is 337 nm from the strong transitions of nitrogen molecules. The new discharge scheme is based on the concept of an arc array amplifier. It essentially consists of 48 pairs of electrodes which are lined up to form an array of arc discharge. Its electrical circuitry allows each pair of the electrodes to be decoupled …
Investigations Of Transverse Arc Array Laser Action In Nitrogen Gas, Kee Siang Goh
Investigations Of Transverse Arc Array Laser Action In Nitrogen Gas, Kee Siang Goh
Student Works (2000-2009)
In almost all pulsed gas lasers, transverse electrical discharge is employed in the excitation of the atoms or molecules. These lasers normally employ discharge across a pair of common electrodes to provide large volume and uniform glow discharge. The scaling of output power in such lasers is obtained by increasing the volume of the discharge and also the pressure of the discharge gas. For this reason. the energy coupled into the discharge channel is kept low enough to avoid arcing. Under these circumstances, the electron temperature of such uniform glow discharge is not sufficient to produce excitation of VUV or …
Nonlinear Self-Organization In Photorefractive Materials, Partha P. Banerjee, Nickolai Kukhtarev, John O. Dimmock
Nonlinear Self-Organization In Photorefractive Materials, Partha P. Banerjee, Nickolai Kukhtarev, John O. Dimmock
Electrical and Computer Engineering Faculty Publications
This chapter discusses self-organization and its effects in optics. One of the most exciting and potentially useful areas of current research in optics involves the understanding and exploitation of self-organization in nonlinear optical systems. This self-organization may sometimes lead to the evolution of complex spatial patterns that can be regarded as the nonlinear eigenmodes of the system. Generation of these patterns is characteristically marked by the presence of intensity thresholds. In a nonlinear system with complicated temporal dynamics, it turns out that one cannot retain purity in spatial dimensionality. It is therefore equally important to investigate the dynamics of the …
New Free-Space Multistage Optical Interconnection Network And Its Matrix Theory, Fengguang Luo, Mingcui Cao, Anjun Wan, Jun Xu, Xinjun Zhou, Cong Deng
New Free-Space Multistage Optical Interconnection Network And Its Matrix Theory, Fengguang Luo, Mingcui Cao, Anjun Wan, Jun Xu, Xinjun Zhou, Cong Deng
Electro-Optics and Photonics Faculty Publications
A new free-space multistage optical interconnection network which is called the Comega interconnection network is presented. It has the same topological construction for the cascade stages of the Comega interconnection. The concept of the left Comega and the right Comega interconnection networks are given to describe the whole Comega interconnection network. The matrix theory for the Comega interconnection network is presented. The route controlling of the Comega interconnection network is decided based on the matrix analysis. The node switching states in cascade stages of the 8 by 8 Comega interconnection network for the route selection are given. The data communications …
Directional Correlation In Direct And Sequential Double Ionization Of Model Atoms, Stanley L. Haan, N. Hoekema, S. Poniatowski, W. C. Liu
Directional Correlation In Direct And Sequential Double Ionization Of Model Atoms, Stanley L. Haan, N. Hoekema, S. Poniatowski, W. C. Liu
University Faculty Publications and Creative Works
We discuss directional dependence in the time development of spatial wavefunctions, which includes jet formation, for two-electron model atoms exposed to intense laser fields. Two competing scenarios for double ionization are evident: (1) both electrons emerge simultaneously from the core region and on the same side of the nucleus, and (2) the electrons detach on opposite sides but not simultaneously. The importance of the electron-electron repulsion contribution to the competing processes is investigated for various laser intensities.
Linear Optics Simulations Of The Quantum Baker’S Map, John C. Howell, John A. Yeazell
Linear Optics Simulations Of The Quantum Baker’S Map, John C. Howell, John A. Yeazell
Mathematics, Physics, and Computer Science Faculty Articles and Research
The unitary evolution of linear optics can be used to model quantum computational networks. In this paper, a quantum simulation of a classically chaotic map (the baker’s map) is developed using linear optics. Two different models are presented. The first model employs only 50-50 beam splitters and phase shifters to simulate universal 2-qubit gates of a quantum computer. The second model uses the discrete Fourier transform generated by symmetric N×N fiber couplers. If single photons are used as inputs for these linear optics models, the result is a physical realization of the quantum baker’s map.
Light Backscatter Of Milk Products For Transition Sensing Using Optical Fibers, Frederick A. Payne, Czarena L. Crofcheck, Sue E. Nokes, Klat C. Kang
Light Backscatter Of Milk Products For Transition Sensing Using Optical Fibers, Frederick A. Payne, Czarena L. Crofcheck, Sue E. Nokes, Klat C. Kang
Biosystems and Agricultural Engineering Faculty Publications
Transition sensors are needed, particularly in the dairy industry, for detecting transitions in pipe flow systems from product-to-water or product-to-product (such as from chocolate to vanilla ice cream mix). Transition information is used to automatically sequence valves to minimize product waste. Optical fibers were used to measure light backscatter between 400 and 950 nm as a function of milk concentration in water and milkfat concentration in milk. The normalized response (100% for product and 0% for water) as a function of product concentration in water was approximately logarithmic for skim milk between 400 and 900 nm and approximately linear for …
Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu
Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu
Electro-Optics and Photonics Faculty Publications
A 16 X 16 Crossover photonic switching network with hybrid integrated CMOS/SEED smart pixel device and 2D optical fiber bundle array I/O access device is reported in this paper. SEEd array devices ar used as light receivers and transmitters, while CMOS devices make efficient logical processing. 4 X 40 2D multilayer optical fiber bundle arrays are fabricated and are used as I/O access devices in the crossover photonic switching network. The center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125micrometers , and the spacing between adjacent layers is 250micrometers . Displacing …
Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu
Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu
Electro-Optics and Photonics Faculty Publications
An optoelectronic switching network with 2-D optical fiber bundle arrays I/O access device is presented in this paper. An optoelectronic recirculating Banyan network based on CMOS/SEED smart pixel device is used in this configuration. Thirty-two X two single-mode fiber bundle array and 32 X 2 multi- mode fiber bundle array are fabricated respectively based on the features of high density, high precision and array permutation of the CMOS/SEED optoelectronic integrated devices. The measuring results show that the center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125 micrometer, and the spacing between …
Guest Editorial: Special Section On Acousto-Optic Devices And Optical Information Processing: Research And Developments, Partha P. Banerjee, Ting-Chung Poon
Guest Editorial: Special Section On Acousto-Optic Devices And Optical Information Processing: Research And Developments, Partha P. Banerjee, Ting-Chung Poon
Electrical and Computer Engineering Faculty Publications
This guest editorial provides an overview of the topical area and an introduction to the articles featured in the special section.
Probing Nonequilibrium Electron Distributions In Gold By Use Of Second Harmonic Generation, K. L. Moore '99, Thomas D. Donnelly
Probing Nonequilibrium Electron Distributions In Gold By Use Of Second Harmonic Generation, K. L. Moore '99, Thomas D. Donnelly
All HMC Faculty Publications and Research
Second-harmonic radiation is generated at a gold surface by use of a laser pulse that is varied in duration from 14 to 29 fs and in intensity from 109 to 1011W/cm2 . At laser intensities below 1010W/cm2 , the second-harmonic signal has the expected quadratic dependence on pump-laser intensity; however, at higher intensities, the dependence is supraquadratic. This difference arises because the leading edge of the laser pulse interacts significantly with the gold electrons to create a nonequilibrium, photoexcited distribution. The second-harmonic generation process occurs before electron–electron or electron–phonon collisions can equilibrate the …
Laser Beam Profile Deformation Effect During Bragg Acousto-Optic Interaction: A Non-Paraxial Approximation, Ray S. Huang, Chen-Wen Tarn, Partha P. Banerjee, Doungchin Cao
Laser Beam Profile Deformation Effect During Bragg Acousto-Optic Interaction: A Non-Paraxial Approximation, Ray S. Huang, Chen-Wen Tarn, Partha P. Banerjee, Doungchin Cao
Electrical and Computer Engineering Faculty Publications
It is commonly known that the spatial profiles of the diffracted light beams during Bragg acousto-optic interaction are distorted due to the Bragg angle selection mechanism. All the conventional studies on this effect use the paraxial approximation. But this approximation should be amended when the incident angle of the light is large enough that the diffracted light waves do not propagate closely along the optic axis of the acousto-optic diffraction system. By using a spatial Fourier transform approach, we rigorously study the light beam profile deformation effect of the diffracted light during the Bragg acousto-optic interaction beyond the paraxial approximation. …
Examination Of Beam Propagation In Misaligned Holographic Gratings And Comparison With The Acousto-Optic Transfer Function Model For Profiled Beams, Monish Ranjan Chatterjee, David D. Reagan
Examination Of Beam Propagation In Misaligned Holographic Gratings And Comparison With The Acousto-Optic Transfer Function Model For Profiled Beams, Monish Ranjan Chatterjee, David D. Reagan
Electrical and Computer Engineering Faculty Publications
A transfer function formalism developed earlier for the propagation of profiled optical beams through acousto-optic Bragg cells is revisited and applied to a thick holographic grating. The results based on the holographic coupled wave model and the acousto-optic multiple scattering model are shown to be compatible, and equivalent parameters such as the Q and grating strength are defined for the two systems. Results for a Gaussian spatial profile are numerically computed and compared. For the holographic grating, a profiled beam may be interpreted as an angular misalignment or Bragg-angle mismatch problem. The case of Bragg-wavelength mismatch is also investigated for …
Differential Reflection Phase Shift Under Conditions Of Attenuated Internal Reflection, R. M.A. Azzam
Differential Reflection Phase Shift Under Conditions Of Attenuated Internal Reflection, R. M.A. Azzam
Electrical Engineering Faculty Publications
The angle-of-incidence dependence of the differential reflection phase shift Δ between p and s polarizations is considered a function of the real and imaginary parts of the relative complex dielectric function ε of an interface in the domain of fractional optical constants, i.e., under conditions of internal reflection. The constraint on complex ε such that oscillatory and monotonic angular responses are obtained is determined. A sensitive and stable technique, which is based on attenuated internal reflection ellipsometry between the Brewster angle and the critical angle, is proposed for measuring small induced absorption (εi∼10−5) in the medium …
Output Control Of Vertical Microcavity Light Emitting Device, James A. Lott
Output Control Of Vertical Microcavity Light Emitting Device, James A. Lott
AFIT Patents
An improved intracavity sensor based output power control for microcavity light emitting devices. An improved phototransistor transducer is both configured and physically disposed so that it passively transmits the spurious optical energy output of the microcavity light emitting device while simultaneously generating a light determined electrical signal of easily used large magnitude that is nearly free of error. The base-collector region of the transistor is disposed with a quantum well absorbing layer and produces a signal responsive to a selected emission wavelength. The configuration of the optical energy communicating transducer is arranged so that it is improved in sensitivity and …