bluuebunny/crossref_metadata_2025 huggingface dataset:
Propagation characteristics of ultrashort pulses in fibers with slowly decreasing dispersion
Authors: Xu Wencheng , Guo Qi , Liao Changjun , Liu Songhao
Published: February 2023

It has been well known that the fibers with slowly decreasing dispersion (FSDD) can be used to compensate for soliton broadening caused by losses in the fibers [1-4].
A new look at the fundamental theorem of diffraction tomography
Authors: Wolf Emil
Published: February 2023

In a paper dealing with three-dimensional structure determination of semi-transparent objects from holographic data1 a theorem was formulated which has subsequently become of considerable importance for diffraction tomography, where it is sometime referred to as the Fourier diffraction theorem.2
Theoretical and experimental studies on seed-beam enhancement in BSO through subharmonic grating formation
Authors: Banerjee Partha P. , Liu Jaw-Jueh , Poon Ting-Chung
Published: February 2023

We analyze subharmonic amplification theoretically and experimentally during the interaction between two pump beams and a seed beam, incident along the bisector of the pumps, in BSO.
Theory of thermal fixing with beam coupling in photorefractive materials
Authors: Jeganathan Muthu , Hesselink Lambertus
Published: February 2023

The diffraction efficiency of a grating during recording and readout can be quite different from a simple exponential or double exponential behaviour predicted by the Kukhtarev model.
Optical solutions for cache memories in parallel computers
Authors: Cheng L. , Sawchuk A. A.
Published: February 2023

A cache is a high speed memory located between processors and main memory to fill the speed gap between them. In a loosely coupled parallel computer, each processor has its own cache memory. The processor accesses information from its cache memory, which stores information obtained from the main memory through an interconnection network. A major challenge in this system is to keep the data in all the caches consistent with that in main memory. This is referred to as the cache coherence problem. One solution is to have a bus between the caches, and supply each cache with a controller which listens to the bus and updates the cache whenever a change is made in main memory. This approach is complicated and is limited by the bandwidth of the bus [1], In a tightly coupled parallel computer, the cache memory can be shared by all processors and there is no cache coherence problem. However, with conventional VLSI implementation, only one processor can access the cache memory at a given time and the performance degrades dramatically [2]. We present optical solutions to the above cache problems. We describe an optical bus which updates the multiple caches in loosely coupled parallel computers to eliminate the bandwidth limitation. Optical or optoelectronic cache memory is proposed for shared cache in tightly coupled parallel computers to allow parallel access. We examine potential architectures and devices for both cases.
Tuning bandwidth enhancement in a LiNbO3 waveguide SHG device using a variable-spaced phase-reversed quasi-phasematching grating
Authors: Fujimura M. , Bortz M. L. , Fejer M. M.
Published: February 2023

We demonstrate 15-fold enhancement of the tuning bandwidth in a waveguide SHG device by using a variable-spaced phase-reversed grating instead of a uniform grating for quasi-phasematching.
Time-to-Space Mapping of Femtosecond Pulses in a Spectral Holographic Correlator
Authors: Nuss Martin C. , Li Melissa , Chiu T. H. , Weiner Andrew M. , Partovi Afshin
Published: February 2023

We report time-to-space mapping of femtosecond optical pulses using spectral holography in a real-time multi-quantum-well (MQW) recording material. Cross-correlations of femtosecond pulses can be read out with a continuous-wave diode laser.
Adaptive RF Notch Filter Using Photorefractive Two-Beam Coupling
Authors: Chang Tallis , Hong John
Published: February 2023

We describe the operation of a photorefractive/acoustooptic system which performs adaptive notch filtering for RF signals using photorefractive two-beam coupling.
Observation of Ultra-Slow Group Velocity and Transparency in Atomic Pb Vapor
Authors: Yin G. Y. , Kasapi A. , Jain M. , Harris S. E.
Published: February 2023

We report the observation of an ultra-slow group velocity of c/126 and transparency in lead vapor in the presence of a transparency-inducing field.
Wave packet motion in B and E fields observed with a phase sensitive technique
Authors: Marmet L. , Held H. , Raithel G. , Yeazell J. A. , Walther H.
Published: February 2023

We report the observation of electronic wave packets of Rb in B and E fields using an interference technique. Measurements in the time domain are explained with a simple classical theory.
Compact, Fast Access Optical Image Correlator Using Orthogonal Data Storage
Authors: Sayano Koichi , Rakuljic George A. , Brost George
Published: February 2023

A compact optical correlator with fast accessability using Fourier transform orthogonal data storage holography is described. Cross-correlation and auto-correlation measurements are also presented.
Accurate Measurements of the Frequency Dependence of Photorefractive Grating Formation in BSO for Signal Processing Applications
Authors: Hong John , Norman Jeffrey , Chang Tallis , Vachss Fred , Pletcher David
Published: February 2023

We describe a novel experiment using acoustooptic devices to generate accurately detuned (0 to 1KHz) writing beams to measure the frequency dependence of photorefractive grating formation in BSO.
Experimental observation of lasing without inversion in Na
Authors: Scully M. O. , Fry E. S. , Li X. , Padmabandu G. G. , Su C. , Zhu S. Y.
Published: February 2023

Atomic coherence gives rise to a series of interesting phenomena in quantum optics.1 In this work we investigate coherence effects within the Na Dl line, demonstrating coherent trapping and lasing without inversion, and study the dependence of these phenomena on buffer gas pressure. Two pump laser beams (I, and I2) are tuned to the frequencies υ1 and υ2 that correspond to the 3S1/2 (F=1, 2) → 3P1/2 transition and are right circularly polarized. Pockels cells are used to turn on or/and off the beams within approximately one nanosecond. To demonstrate lasing without inversion, a weak pulse of left polarized light tuned to t)2 was used to create a small population in the upper level (3P1/2) and the amplification of I, was observed. We found a significant gain in the absence of population inversion, which was verified by a direct experimental observation. These results were observed as a function of buffer gas pressure. The atomic coherence effects are shown to disappear in the presence of a helium buffer gas at a pressure of ≈ 1 Torr; whereas, complete optical pumping is only achieved at helium buffer gas pressures >10 Torr.
Optically bistable cavity driven by the output of another optically bistable cavity
Authors: Gripp Jurgen , Orozco Luis A.
Published: February 2023

The canonical optically bistable system of two-level atoms inside a cavity can produce non-classical light.1 We investigate a more complex system formed by two of them. The output of the first cavity drives the second, but otherwise the two cavities are uncoupled.
Quantum atomic dots: a new approach to gravimetry
Authors: Dowling Jonathan P.
Published: February 2023

Recent advances in semiconductor technology have led to the ability to dimensionally confine electron motion, and semiconductor configurations that limit electron motion to zero macroscopic dimensions are known as quantum dots.1 The dimensions of confinement are on the order of the de Broglie wavelength of the electron, leading to a manifestation of the particle-in-a-box atom-like energy levels.
Observation of transient all-optical switching in C60
Authors: Wang Ruibo , Guo Fengyun , Yang Kun , Li Chunfei
Published: February 2023

Recently, studies on the photophysical properties of C60 have shown that the population of the first excited singlet state(S1) can be transferred to the first excited triplet state (T1) with a quantum yield higher than 96% by intersystem crossing with a relaxation time about 1ns.
Signal self-thresholding using wavelength-division-multiplexed differential transmission for photonic ATM switches
Authors: Misawa Akira , Nakano Hidetoshi , Matsunaga Tohru
Published: February 2023

Several photonic systems for ATM-based switching have been proposed that are expected to overcome some of the electronic limitations.
Unified approach to electromagnetic scattering by cylinders and spheres
Authors: Milham Merrill E.
Published: February 2023

Solutions of electromagnetic scattering problems are obtained by appropriate application of the Maxwell electromagnetic equations to scattered of a specified geometry. Formal solutions for the scattering by cylinders and spheres are well-known, classic results of this approach. This paper presents a unified theory of electromagnetic scattering for infinite cylinders and spheres, in which the scattering coefficients have a common functional form with the geometry being determined by whether half-integer (sphere) or integer (cylinder) order Bessel functions are used. The application of the theory to the development of new scattering codes is also described.
Quasi probability distribution for the field in the Dicke model
Authors: Sanchez-Mondragon J. J. , Chumakov S. M. , Castro-Beltran H. M.
Published: February 2023

We have calculated (both, analytically1 and by computer) the Q-function (quasiprobability distribution in the field phase space) for a system of N two-level atoms interacting with the quantum e.m. field in a lossless cavity. For the one atom case the analogous problem has been solved in the work.2 The field was supposed to be initially in a coherent state. For arbitrary initial atomic state, the Q-function has N+1 humps of Gaussian form. When all these humps are essentially separated in the phase space the photon number and atomic inversion oscillations are collapsed. If some of the humps overlap it results in the oscillations revival. We have found N+1 initial atomic states for which the system wave function is approximately factorized into the product of the field and atomic wave functions. The atomic entropy has been calculated in order to estimate the accuracy of this factorization.
Efficient power transfer between nonidentical vertically coupled channel waveguides in different cladding media
Authors: Armenise M. N. , Conese T. , Barbarossa G.
Published: February 2023

Vertical integration of high-silica channel waveguides on Si substrate has been recently demonstrated by flame hydrolysis deposition.
Two-beam coupling- and response-time measurements in strontium barium niobate crystals doped with different concentrations of chromium
Authors: Yarrison-Rice Jan M. , Klank Robert , Kwiatkowski Mike , Waldon Wade , Sharp Edward J. , Wood Gary L. , Neurgaonkar Ratnakar R.
Published: February 2023

The role of chromium dopant concentration in photorefractive strontium barium niobate is investigated in two 5 mm cubed crystals doped with 0.011% and 0.06% chromium and one 0.5 mm thick (0.06% chromium). Two-beam coupling, grating formation and erasure times, and beam fanning are utilized to extrapolate several material parameters from these crystals.
Spatial solitons in dye solutions and photorefractive crystals with a local mechanism of nonlinearity
Authors: Iturbe Castillo M. D. , Marquez Aguilar P. A. , Sánchez-Mondragón Stepanov J. J. , Vysloukh V.
Published: February 2023

The possibility of exciting spatial solitons using moderate power CW lasers appears promising for optical interconnects, communication, and information processing. In addition to the dye solutions (using ethanol, acetone, etc.) where the dark soliton excitation by Ar-ion lasers was reported recently (see e.g.1), photorefractive crystals (PRCs)2 are also highly suitable for these applications.
Generation of high-order solitons from a mode-locked Ti:sapphire laser
Authors: Tsang Thomas
Published: February 2023

The advent of femtosecond lasers has lead to the production of solitonlike pulses in colliding pulse modelocked (CPM) lasers.1–4 In this conference, we present the production of such solitonlike pulses in another laser system—a self-mode-locked Thsapphire laser.5
Hot-electron mechanism for a de photorefractive phase shift
Authors: Wang Q. N. , Brubaker R. M. , Nolte D. D. , Melloch M. R.
Published: February 2023

Photorefractive AlGaAs/GaAs multiple quantum well structures exhibit strong photorefractive two wave mixing1 in the transverse-field geometry. The phase shift of the photorefractive grating approaches π/2 for DC fields above Ec = 4 kV/cm. The four-wave mixing diffraction efficiency2 saturates for fields larger than Ec.
Theory of propagation of intense, ultrashort laser pulses in underdense plasmas
Authors: Borisov A. B. , McPherson A. , Boyer K. , Rhodes C. K.
Published: February 2023

The theory of spatial and temporal propagation of high power subpicosecond laser pulses in cold undercritical plasmas is presented. This research can be regarded as the continuation of our earlier theoretical and experimental studies.1–3
Converting powerful multimode fields into a single spatial mode using a semi-linear phase conjugate mirror
Authors: Jaatinen Esa , Luther-Davies Barry
Published: February 2023

A semi-linear phase conjugate mirror (SLPCM) consists of a photorefractive oscillator formed between an ordinary mirror and a phase conjugator (in our case this was Barium Titanate).1 The oscillator would normally be pumped by a single mode laser beam whereas the cavity oscillation generally occurs over many spatial modes.
Steel-plate magic mirror
Authors: Lin K F. , Yang W.
Published: February 2023

The so called “light-penetrating mirror” was considered an ingenious achievement in optical and metallurgical techniques in ancient China.1 The front side of the mirror is a smooth reflecting surface and the rear side is engraved with several Chinese epigraphs.
Phase unwrapping using a sequentially updated cellular processor
Authors: Servin M. , Rodriguez-Vera R. , Malacara D.
Published: February 2023

Fringe analysis is the backbone procedure in many techniques of Optical metrology. These optical metrologies may range from testing image formation optical systems, to electronic speckle metrology.
Important clinical and functional differences between grating-contrast sensitivity and low-contrast letter acuity
Authors: Ginsburg Arthur P.
Published: February 2023

Contrast thresholds for sine-wave gratings (SWG) using VDT and chart (Ginsburg), Snellen charts and low contrast letter (LCL) charts (Pelli–Robson and Regan) are compared: to measure clinically and functionally meaningful ranges of spatial frequencies or sizes and contrast; absolute and differential contrast sensitivity; and relationship to clinical and functional vision. When these data are plotted on the same contrast sensitivity versus spatial frequency graphs important differences between the SWG and LCL are revealed.
Visual-receptive-field model based on the Zak transform
Authors: Gertner Izidor C. , Geri George A.
Published: February 2023

Since Gabor functions do not form an orthogonal basis, a biorthogonal auxiliary function is required to determine expansion coefficients. A computationally efficient, 4-D FFT algorithm, based on the Zak transform, has previously been developed1 to calculate Gabor coefficients.
Measurement of inelastic scattering in Monterey Bay
Authors: Ge Yuntao , Voss Kenneth J. , Gordon Howard R.
Published: February 2023

Data obtained in the coastal Pacific Ocean in Monterey Bay shows that the overall behavior of the Fraunhofer lines agrees with theoretical predictions.1 However in the measured data the filling is much faster than can be predicted by Raman scattering alone thus the contribution of other sources of inelastic scattering to the light field is significant.
Tunnel ionization of simple molecules by an intense CO2 laser
Authors: Walsh T.D.G. , Ilkov F.A. , Chin S.L.
Published: February 2023

Experimental results related to the investigation of the behaviour of various simple (i.e. H2,N2,O2,CO,NO,CO2) molecules present in an intense CO2 laser field lead to the conclusion that all of the species ionize before dissociating.1,2
Interference-controlled excitation of a hybrid resonance in Xe
Authors: Garrett W.R. , Brandon W.D.
Published: February 2023

In well studied examples of multi-photon driven hybrid resonances, a resonant or near resonant transition in a simple molecule or in atoms during collision, leads to a “product” which subsequently is further excited.
Continuous-wave-laser resonance-ionization mass-spectrometric analysis of strontium
Authors: Perera Indral K. , Lyon Ian C. , Van Lierde Patrick , Turner Grenville
Published: February 2023

In recent years, resonance ionization mass spectrometry (RIMS), has emerged as a highly selective and sensitive method for elemental and isotopic analysis.1
Generalization of induced transparencies in semiconductor quantum wells
Authors: Lee Dong S. , Malloy Kevin J.
Published: February 2023

Linear and nonlinear mechanisms for induced transparencies in semiconductor quantum wells using intersubband coupling are analyzed by exactly solving a general set of density matrix equations.1
Electromagnetically induced transparency and resonant nonlinear optical generation in atomic hydrogen
Authors: Hakuta K. , Zhang G. Z. , Ohta M. , Thompson R. I. , Stoicheff B. P.
Published: February 2023

Recently, Hakuta, Marmet, and Stoicheff1 have proven the possibility of obtaining high conversion efficiency for second-harmonic-generation (SHG) in atomic hydrogen using dc-electric-field induced transparency.
Incoherent fiber-optic correlator based on time-integrating techniques
Authors: Euliss G. W. , Athale R. A.
Published: February 2023

Optical correlator architectures using fiber optic tapped delay lines are of interest because of the potential for achieving very high time-bandwidth products.
Profile modification of laser beams by acousto-optic Bragg diffraction
Authors: McNeil Mark , Poon Ting-Chung
Published: February 2023

We investigate acousto-optic Bragg diffraction of Gaussian laser beams.
Acousto-optic interactions between arbitrary light and sound fields
Authors: Banerjee Partha P. , Zou Kun
Published: February 2023

A novel approach for analyzing acousto-optic interactions1 between arbitrary incident light and sound field is presented.
Compact, multiterawatt, sub-100-fsec laser system using a flashlamp-pumped, dye-converted Ti:sapphire amplifier
Authors: Reitze David H. , White William E. , Price Dwight F. , Shepherd Ronnie L. , Bonlie James D. , Hunter James R. , Peressini Dennis L.
Published: February 2023

Recent advances in large gain-bandwidth solid state amplifying materials combined with the technique of chirped pulse amplification have resulted in the development of laser systems capable of producing 100 fsec, multi-terawatt pulses1.
Evolution of a high-intensity laser-plasma interaction on a femtosecond time scale
Authors: Umstadter Donald
Published: February 2023

It is now possible with the technique of chirped pulse amplification to build compact solid-state lasers that produce ultrashort pulses with intensities three to four orders of magnitude higher than was previously possible.1
Tunneling dynamics of squeezed states in a potential well
Authors: Lenef A. , Rand S. C.
Published: February 2023

We investigate the effect of squeezing on tunneling from a simple potential well to a continuum of final states.
Generation of squeezed states by holography
Authors: Liu Shangqing
Published: February 2023

A scheme for generating squeezed states of light is suggested.
Anti-Stokes generation in stimulated Raman scattering
Authors: Scalora M. , Bowden C.M. , Haus J. W.
Published: February 2023

We consider diffractive coupling in stimulated Raman scattering when an anti-Stokes wave co-propagates in a Raman active medium.
Use of chirped pulses for improved femtosecond holographic storage
Authors: Weiner A. M.
Published: February 2023

The use of holographic techniques for storage and processing of ultrafast optical signals has been reported by several authors.1–3
Ultrafast, large-dynamic-range absorption spectroscopy of slow relaxations in condensed systems
Authors: Cheville R. A. , Averitt R. D. , Halas N. J.
Published: February 2023

Nonexponential photoinduced relaxation processes that occur over many timescales are often found in condensed matter systems, such as amorphous semiconductors, chalcogenide glasses, or conductive polymers.
Femtosecond time-resolved optical Kerr effect as four-wave mixing
Authors: Dickson T. R. , Sipe J. E. , Kenney-Wallace G. A.
Published: February 2023

Measurements of the optical Kerr response induced by ultrashort pulses have been used for some time as a gauge of picosecond and femtosecond motions in transparent liquids and solids.1,2
Prediction of optical-wave front variance: integral equation technique versus small- aperture beam technique
Authors: Hugo Ronald J. , Jumper Eric J. , Cicchiello James M.
Published: February 2023

The optical wave front variance is predicted by two techniques, the first consists of hot-wire anemometry measurements and an integral equation involving density-variance and density length-scale distributions1,2 and the second consisting of the small-aperture, multiple beam technique.3,4
High-accuracy measurement of the refractive index of air by using two frequency-doubling crystals
Authors: Matsumoto Hirokazu , Zeng Lijiang
Published: February 2023

Interferometric method enables measurement of lengths with high relative accuracy.
Experiments with a separated-beam atom interferometer
Authors: Pritchard David E. , Ekstrom C. , Schmiedmayer J. , Chapman M. , Hammond T.
Published: February 2023

Three 0.2 micron period diffraction gratings were combined to realize an atom interferometer1 in which the interfering beams are distinctly separated in both position and momentum. A 10 cm long foil 10 microns thick was positioned symmetrically between two side electrodes, so that the atom wave in the two sides of the interferometer went on opposite sides of it. The fringe amplitude was 820 cps, which allows us to determine the phase to 15 milliradians in 1 minute.2
In-line fiber-optic measurement of the state of polarization: experimental results
Authors: Alam Mahmood , Habli M.A.
Published: February 2023

In line measurement of the state of polarization of a lightwave traveling in a fiber is described. Different fibers are used including D-shape fibers.
Fringe-shape-stabilization system for a bi-refringent-fiber-ring resonator
Authors: Mouroulis Pantazis , Narayanan S. Anantha
Published: February 2023

All types of birefringent (but not polarizing) fiber ring resonators present environmentally-induced variations in the fringe shape that cannot be eliminated passively.1 A fringe shape stabilization system has been constructed, for use with fiber ring resonators with power exchange between the birefringent axes.2-4 The system works by keeping the depth of successive resonant dips equal, through a feedback loop that controls the fiber birefringence Δn. Two schemes for controlling Δn are investigated: in the first less efficient scheme, the entire loop is subjected to stretching, causing a fringe drift of more than 100 fringes. In the second scheme, the fiber is subjected to a localized compression, which changes Δn while having only a small effect on the average refractive index, thus causing a smaller fringe drift. When the resonator is used as a high-resolution spectrum analyzer, either stabilization scheme can be used; but the second scheme allows the resonator to be also used as a sensor, as it interferes little with the signal recovery system. With this stabilization system the resonator can operate in a variable environment with minimal deterioration in performance.
Lasing without inversion by interference of electron momenta
Authors: Kurizki Gershon , Scully Marian O. , Keitel Christoph
Published: February 2023

We put forward novel schemes wherein lasing is attained by coherent superpositions of two free electronic states in interfering interaction regions that suppress stimulated absorption without hampering stimulated emission. This can strongly enhance the gain of a free-electron laser. In the first scheme an electron beam with mean momentum

k
→

1

interacts with wiggler mode

k
→

w
1

in region 1, changes its momentum (by deflection) to

k
→

2

and interacts with wiggler mode

k
→

w
2

in region 2. The interactions in both regions add coherently, provided both wiggler beams are from the same coherent source, and the signal photon is delayed to allow interaction with the same electron in both regions. Absorption of the signal photon in regions 1 and 2 scatters the electron into a common final state

|

k
→

a

>

if

k
→

a

≈

k
→

1

−

k
→

w
1

+

q
→

=

k
→

2

−

k
→

w
2

+

q
→

. This is the condition for interference that can suppress absorption. The final states for emission,

|

k
→

e
1

>

and

|

k
→

e
2

are then strongly orthogonal, whence there is no interference in emission. In another scheme, the wigglers are replaced by Cherenkov or Smith–Purcell effects. Coherently superposed electron momenta

k
→

1

and

k
→

2

propagate in two sequential structures with different dispersion relations. Interference in signal absorption at frequency ω and direction z by both structures occurs for a common final electronic state

|

k
→

a

>

satisfying

k
→

a
z

≃

k
→

1
z

+

q

1
z

(
ω
)
≃

k
→

2
z

+

q

2
z

(
ω
)

, where

q
→

1

(
ω
)

and

q
→

2

(
ω
)

are the respective wavevectors. Here too interference in emission is prevented by the orthogonality of the respective final states

k
→

e
i

=

k
→

i

−

q
→

i

(
ω
)
,
(
i
=
1
,
2
)

.
Lasing without population inversion in ruby
Authors: Wu Cunkai , Zhao Yang
Published: February 2023

Lasing without population inversion was studied in a three-level solid state medium of ruby. The two closely-spaced lower levels are the Zeeman split sublevels of the ground state 4A2 of ruby, corresponding to M=−3/2 and M=+l/2. The transition between the lower levels is the electric dipole-forbidden. When the angle between the constant magnetic field and C-axis of ruby is 90°, the transition matrix element of the electric dipole-forbidden transition is quite large.1 A strong microwave field which operates at K-band coherently couples the two lower levels.2 Changing the constant magnetic field intensity or adjusting the frequency of the pumping microwave field, the exact resonant excitation can be established. The upper level of the lasing process is the Zeeman split sub-level M=−l/2 of 2E state. The ruby crystal, with about 0.05% chromium concentration, is placed at the center of a cylindrical cavity and cooled by liquid helium. With 500 Gauss magnetic field, the coupling microwave frequency is 13.1 Ghz and the required power is around 100 W/cm2.
Time evolution of coherent excitonic wave packets in coupled quantum wells and superlattices
Authors: Dignam M. M. , Sipe J. E. , Shah Jagdeep
Published: February 2023

In recent experiments, short-pulse excitation of undoped semiconductor double quantum wells1 and superlattices2 in an electric field has been used to form excitonic wavepackets from a coherent superposition of the underlying stationary states. We examine the wavepacket evolution, including the Coulomb interaction between the electrons and holes, as well as the effects of the terahertz radiation field resulting from the wavepacket oscillation. It has been suggested that in superlattices, the time evolution of these wavepackets represents Bloch oscillations. We investigate the evolution of such wavepackets as a function of the excitation parameters and discuss the degree to which Bloch oscillations can be achieved.
Effects of electron-electron scattering on dephasing of interband polarization in semiconductor quantum wells
Authors: Young Jeff F. , Hawrylak P. , Brockmann Peter
Published: February 2023

The energy dependence of the dephasing rate of coherent interband polarization in modulation doped quantum well structures1 will be discussed from a many-body perspective. It will be shown that collective two-dimensional plasmon emission processes associated with both the electron and light-hole wavefunction components of the polarization can be expected to give rise to discontinuities in the dephasing rate as the excitation energy is tuned within < 50 meV above the absorption edge in GaAs quantum wells. The exact position and magnitude of these discontinuities is very sensitive to the approximation used to treat local field effects because of the relatively large wavevector transfers involved in the hot-carrier/Fermi sea interaction. This type of coherent measurement may therefore provide a probe of the exchange-correlation properties of the two dimensional electron gas.
Design relations for resonant waveguide-grating filters
Authors: Magnusson R. , Wang S. S.
Published: February 2023

The resonance effect associated with waveguide gratings is due to coupling between the propagating diffracted waves and the modes of the waveguide. Efficient narrow-line reflective filters can be designed using this principle. These filter elements do not require Bragg conditions or Fabry–Perot resonances for their operation. By identifying the effective waveguide-grating propagation constant, approximate design relations for the resonant filters can be established using the theory of dielectric slab waveguides.1 In this paper, quantitative description of the parametric resonance regions of slanted and unslanted waveguide grating filters with small modulation will be presented. Expressions for the upper bounds of the filter linewidths are given. The validity of the formulas found is tested with the rigorous coupled-wave theory with respect to the grating modulation amplitude. The polarization characteristics of these structures are discussed. Design examples employing the analytical relations will be presented with final filter characteristics calculated numerically. This work was partly supported by the Texas Advanced Technology Program under grant no. 003656-023 and by the National Science Foundation under grant no. ECS9120856. 1. R. Magnusson and S. S. Wang, Appl. Phys. Lett. 61, 1022 (1992).
Approximate analytical solutions of the rigorous coupled-wave equations: application to resonant waveguide filters
Authors: Wang S. S. , Magnusson R.
Published: February 2023

We have derived analytical, approximate solutions to the rigorous coupled-wave equations.1 The expression found for the diffracted wave amplitudes have been applied to unslanted guided-mode resonance grating filters to predict the resonance line shape and location. For a single-mode waveguide grating at normal incidence, both symmetric (±1 diffracted orders) evanescent waves are retained along with the forward- and backward propagating zero orders such that an effective three-wave solution is obtained. For non normal incidence and dominant coupling to the +1 evanescent wave (with the −1 order coupling being negligible), a two-wave solution is found that is similar to the two-wave result of Kong.2 Both the three-wave solution and the two-wave solution have been tested against numerical solutions using the full rigorous coupled-wave theory and excellent agreement found. The analytical solutions expedite calculations of the characteristics of waveguide-grating filters and may provide some additional insights into their properties. This work was partly supported by the Texas Advanced Technology Program under grant no. 003656-023 and by the National Science Foundation under grant no. ECS-9120856.
Enhancement and inhibition of radiation in spherically symmetric structures
Authors: Sullivan Kevin G. , Erdogan Turan , King Oliver , Hall Dennis G.
Published: February 2023

The presence of an interface or structure can significantly impact the characteristic behavior of a radiating system. Specifically, frequency and lifetime shifts induced by the structure are interpretable within the context of creating a “photonic bandgap,” i.e., an energy band for which wave propagation is isotropically forbidden. Utilizing a classical model, we directly treat the interaction of a radiating dipole within a spherical Bragg structure. The real and imaginary portions of the reflected field, evaluated at the source position, determine the lifetime variations and frequency shifts, respectively.1 Employing a Green’s function method, we derive and numerically solve coupled-amplitude equations within the Bragg region. This method is part of a rigorous 3-D vector formulation used in determining the reflected field strength. We examine radiative lifetime variations and resonance frequency shifts for idealizations of the structure and source. We also show that the spherical structure is capable of inhibiting radiation from a central, finite-sized region. These calculations are of fundamental interest for understanding dipole-surface interactions, particularly in 3-D spherical geometries requiring a vector formulation; the development is also of potential practical interest as applied to spherical cavity and photonic structure design.
Electron number density and temperature in a transient hydrogen plasma
Authors: Parigger C. , Plemmons D. H. , Lewis J. W. I.
Published: February 2023

It is of interest to characterize the laser-induced optical breakdown plasma that is generated in an atmospheric pressure hydrogen gas.1 Time-resolved spectroscopy methods are employed to measure the plasma emission spectra. Comparison with tabulate line profiles2 of the hydrogen-alpha line and Boltzmann-plot method3 allow us to infer electron number density and temperature.
Difference-frequency generation of 4-μm radiation from Nd:YAG lasers
Authors: Wong S. K. , Oliver R. , Schepler K. L.
Published: February 2023

Mid-infrared radiation is useful for chemical detection, remote sensing and laser radar in the atmosphere.
Self-phase-matching mechanism for efficient harmonic generation processes in a ring pump-beam geometry
Authors: Glushko B. , Kryzhanovsky Israel B. , Sarkisyan D.
Published: February 2023

A new type of phase matching based on a ring-shaped pump beam for efficient sum-frequency-mixing (harmonic-generation) processes in isotropic media is studied theoretically and experimentally.
Velocity-selective coherent population trapping in conjunction with pol-grad cooling in a folded three-level system under standing wave excitation
Authors: Katz D.P. , Shahriar M.S. , Hemmer P.R. , Prentiss M.G. , Bigelow N.P.
Published: February 2023

We identify the conditions under which velocity selective coherent population trapping (VSCPT) takes place when a three level Λ system is excited by a pair of Raman resonant standing waves.
Sub-Doppler laser cooling of triplet metastable He
Authors: Widmer M. , Bellanca M.J. , Vredenbregt E. , Bergeman T. , Metcalf H.
Published: February 2023

We have discovered peaks as narrow as a single recoil vrec ≡ ħk/M in the transverse velocity distribution of our laser-cooled metastable He beam (He*).
Light-intensity dependence of collisional loss for sodium atoms in a magneto-optical trap
Authors: Marcassa L. , Bagnato V. , Wang Y. , Weiner J. , Julienne P. , Bigelow N. , Band Y.
Published: February 2023

We have studied the collisional loss rate as a function of light intensity for sodium atoms held in a magneto-optical trap1.
Evolution of new optical-measurement techniques from the quantum domain
Authors: Mandel L.
Published: February 2023

We have recently carried out optical interference experiments for the purpose of studying certain quantum mechanical interference effects. It turns out that some of the techniques developed have possible applications to optical precision measurements.
Phase imaging in confocal microscopy by optical differentiation
Authors: Kulawiec Andrew W. , Moore Duncan T.
Published: February 2023

Optical differentiation through coherent optical processing has been shown to be an effective method for phase visualization.1
Interconnections between fundamental-color spaces and opponent-color spaces
Authors: Scheibner Horst
Published: February 2023

A set of three spectral fundamental color functions is assumed to be available, functions that can be interpreted as spectral sensitivities of the three retinal cone types.
High-precision spectroscopy with diode lasers
Authors: Zibrov A. , Fox R.W. , Weimer C. , Hollberg Leo
Published: February 2023

Diode lasers are unique in providing tunable, single-frequency laser light from a compact high efficiency source. We have been exploring the application of these devices to very high resolution spectroscopy and precision measurements.
Novel calculation of higher-order modes of waveguides by using beam-propagation method
Authors: Jüngling S. , Chen J. C. , Kärtner F. X.
Published: February 2023

Recently, Yevick and Hermansson1 showed that propagation along the imaginary axis can give the fundamental mode and its effective index efficiently.
Semiconductor-optical-amplifier design for fiber-optic systems
Authors: Raja M. Yasin Akhtar
Published: February 2023

Semiconductor optical amplifiers (SOA) are the important elements in optoelectronic circuits and systems to boost weak signals from distant fiber-optic links, and to overcome splitting losses.
Performance optimization in guided-wave acousto-optic devices by controlling the diffraction efficiency
Authors: Armenise Mario N. , Matteo Anna Maria , Passaro Vittorio M. N.
Published: February 2023

A detailed four-wave model of acousto-optic (AO) interaction1 in devices formed by planar waveguides and interdigital AO transducers has been used in this paper to identify the highest Bragg diffraction efficiency configurations with reference to the crystal orientation, monomodal guiding parameters, transducer driving radio frequency, f and acoustic loss.
Evolving solitons in mode-locked fiber lasers
Authors: Stentz Andrew J. , Boyd Robert W.
Published: February 2023

The development of mode-locked fiber lasers has recently become the subject of intense research.1,2 While the output of these lasers can exhibit small shot-to-shot energy fluctuations, we show here that the output pulsewidths can fluctuate dramatically.
Frequency stabilization of a laser-diode- pumped YVO4 intracavity-doubled laser by using an iodine cell
Authors: Matsumoto Hirokazu , Carty Timothy , Tokuyuki Honda
Published: February 2023

Laser-diode-pumped solid-state lasers are well suited for applications in optical metrology, coherent optical communication, and optical data storage.
Optical implementations of adaptive-resonance-theory neural architectures
Authors: Caudell Thomas P.
Published: February 2023

Adaptive resonance theory (ART) neural networks are becoming an important component of neural network industrial applications.
Validity of quasi-homogeneous approximation
Authors: Foley John T. , Wang Ming
Published: February 2023

In 1977 Carter and Wolf introduced the concept of a quasihomogeneous planar source.
Optical pulse propagation at abnormal group velocities through transparent inverted-population media
Authors: Bolda Eric L. , Chiao Raymond Y. , Garrison John C.
Published: February 2023

We show that, in a medium with an inverted population, waves with frequencies outside the gain band will propagate with abnormal (i.e. superluminal or negative) group velocities.
M2 beam-quality meter for pulsed lasers
Authors: Duncan M. D. , Ruff J. A.
Published: February 2023

Laser beam quality measurements have become important diagnostics for laser operation and beam propagation. A commercial instrument, based on the M2 method of defining beam quality,1 has been developed for CW lasers.2 We have constructed and tested an equivalent instrument for measuring the beam quality of a single shot of a pulsed laser.
Instrumentation techniques for beam quality and propagation-parameter measurement
Authors: Sasnett M. W. , Johnston T. F.
Published: February 2023

Since “beam diameter” is a somewhat ambiguous concept and not yet standardized, instruments that measure beam diameters often adhere to differing conventions.
Noise and minimum signal energy in Brillouin amplification
Authors: Jones D. C.
Published: February 2023

Amplifiers and phase conjugate mirrors based on stimulated Brillouin scattering have been studied extensively owing to their ability to achieve very high gain and sensitivity.
Grating-based InP components for WDM networks
Authors: Soole J. B. D.
Published: February 2023

Wavelength division multiplexed (WDM) systems are being considered for application in telecommunications in both the long haul and local-area telephone networks, for communications between processors in computing systems, for ‘fly-by-light’ aircraft data systems, and for a variety of sensor applications.
Observation and suppression of quantum phase waves in a mode-locked laser
Authors: Harvey J. D. , Hirst D. B. , Carter S. J. , Drummond P. D.
Published: February 2023

Recently it has been shown1 that the pulse characteristics of the mode locked argon laser on the Q of the cavity can only be explained by a swept gain superfluorescent model based on the optical Bloch equations.
Classical analysis of microcavity lasers
Authors: Ram R. J. , York R. A. , Babic D. I. , Bowers J. E.
Published: February 2023

Antenna theory is developed for the study of spontaneous emission by atomic dipoles in microcavity lasers.
Quantum theory of the microlaser
Authors: De Martini F.
Published: February 2023

The phase-transition analogy of the thresholdless microlaser will be fully analyzed by including the fluctuation contributions of the atomic reservoir and of the emitted field.1-3
Optical laser resonators: a global analysis according to the second-moment theory
Authors: Bélanger P.-A. , Paré C.
Published: February 2023

The second-moment method permits one to follow the propagation of a general optical beam through a paraxial system (described by an ABCD ray matrix) by using the generalized complex radius of curvature Q1.
Performance of unstable resonators with phase-step mirrors
Authors: Cantin Daniel , Piché Michel
Published: February 2023

Unstable resonators are capable of generating coherent beams of large dimension, but suffer from inherent losses due to geometrical magnification.
Fast-transform beam-propagation algorithms with greater flexibility
Authors: Morin Michel
Published: February 2023

Fast transform beam propagation algorithms have been introduced, for both cartesian and cylindrical coordinates [1,2].
An effective high-data-throughput optical matrix crossbar network
Authors: Zhou Shaomin , Yeh Pochi , Yang Xiangyang , Liu Hua-Kuang
Published: February 2023

A crossbar switching network is important for data communication, digital computing, and neural network applications.
Effect of erasure dynamics on the storage capacity of wavelength-multiplexed reflection-type photorefractive holograms
Authors: Zhou Hanying , Zhao Feng , Yu Francis T. S.
Published: February 2023

The problem of recording a multiplexed photorefractive hologram with equal diffraction efficiencies is rather complicated by both the grating formation and the erasure dynamics of the PR material.
Squeezing and suppression of guided-acoustic-wave Brillouin scattering with 1-GHz pulses
Authors: Bergman K. , Haus H. A. , Ippen E. P. , Shirasaki M.
Published: February 2023

Squeezing for the purpose of noise suppression can be performed by using the Kerr effect in fibers.1 The best noise suppression is achieved using pulses for the pump.
Spatial effects in traveling-wave squeezed-state generation and detection
Authors: Kim Chonghoon , Li Ruo-Ding , Kumar Prem
Published: February 2023

Recent experiments that have demonstrated the generation of quadrature-squeezed light in the traveling-wave configuration of an optical parametric amplifier (OPA) indicate that the observable squeezing is largely limited by the effects of diffraction in the parametric process1 and by the spatio-temporal mismatch between the generated squeezed mode and the local-oscillator (LO) mode employed in homodyne detection of squeezing.2
Improved squeezing in multilayer semiconductor GaAs-AlAs waveguides with third-order nonlinearity
Authors: Zhang Xiaolong , Udo Maria K. , Ho Seng-Tiong
Published: February 2023

The generation of squeezed-state light in χ(3) media has been demonstrated in various systems.
Nonclassical intensity correlations in the detection of squeezed light
Authors: Vyas Reeta , Dodson Arlis , DeBrito A. L.
Published: February 2023

We consider intensity correlations when squeezed light from a degenerate parametric oscillator (DPO) is superimposed with coherent light at a beam splitter.
Effect of laser-induced continuum structures (LICS) of above-threshold ionization
Authors: Dutton Michael E. St. J. , Dalton Bryan J.
Published: February 2023

LICS1 call be produced by embedding a bound atomic state into an atomic continuum via a strong laser field, and probed from a second bound state with another laser.
Autler-Townes absorption spectrum of a bichromatic field
Authors: Papademetriou Stephanos , Van Leeuwen Michael F. , Stroud Carlos R.
Published: February 2023

The interaction of a strong bichromatic field with a two-level atom has been the subject of numerous experimental and theoretical investigations, but some outstanding questions remain concerning the widths of the various lines in the spectra.
Optical encoding of a stun-frequency grating in silica-based glass
Authors: Driscoll T. J. , Lawandy N. M.
Published: February 2023

It has previously been demonstrated that simultaneous irradiation of glass by fundamental laser light and its second harmonic (ω + 2ω) may optically encode glass materials for efficient second harmonic generation.
Spatial refractive-index distribution and power dependence of self-organized Bragg gratings in germanosilicate fiber
Authors: Campbell R. J. , Kashyap R.
Published: February 2023

Since the first observation of self organizing Bragg gratings in germanium doped silicate fibers [1] 1978, no accurate experimental measurements of the refractive index perturbation along the fiber length have been reported.
Multilayer modal method for diffraction gratings of arbitrary profile, depth, and permittivity
Authors: Li Lifeng
Published: February 2023

It is well known that a diffraction grating of arbitrary profile can be approximated by a stack of lamellar (rectangular groove) gratings, and that the diffraction of light by the arbitrary-profile grating can be modeled by the modal method1 that is specifically formulated to model lamellar gratings.
Multiple reflection and interference within a chiral medium
Authors: Silverman M. P. , Badoz J.
Published: February 2023

The differential reflection of left and right circularly polarized light by a naturally chiral absorbing medium has recently been measured with a sensitivity of a few parts per million.
Optimal phase function for gradient-index optical filters
Authors: Druessel J. J. , Grantham J. W. , Haaland P. D.
Published: February 2023

Fourier transform techniques for design of gradient-index optics have previously used arbitrary forms for the complex part of the reflectance profile.
Accurate propagation beam solution of the paraxial wave equation by using the Richardson extrapolation
Authors: Chinni V. R. , Menyuk C. R. , Wai P. K. A.
Published: February 2023

It is useful to have highly accurate, yet rapid schemes for solving the paraxial wave equation.
Large spontaneous-emission coefficients in semiconductor microdisk lasers
Authors: Slusher R. E. , Mohideen U. , McCall S. L. , Levi A. F. J.
Published: February 2023

A large portion (approximately 10%) of the spontaneous emission from InGaAs quantum wells is emitted into the lasing mode for microdisks with diameters near 2 μm.
Lasing and fluorescence from BIS-MSB-dye-doped polystyrene microspheres
Authors: Sheng W. , He K. X. , Venkateswarlu P. , Sharma A. , Vanderhoff John W. , Chen Jing-Hong , Kornfield Dale , Penn Benjamin G. , Frazier Donald O. , Witherow William K.
Published: February 2023

Excimer laser induced fluorescence from 2.6 pm polystryrene microspheres doped with BISMSB dye shows the characteristic morphology-dependent-resonances associated with microdroplet lasers.