bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Magnetooptics : Giant Photoinduced Faraday Effect in Diluted Magnetic Semiconductors
Authors: Hugonnard-Bruyère S. , Frey J. , Frey R. , Flytzanis C.
Published: February 2023

The propagation characteristics of a laser beam can be modified by nonlinear optical processes that proceed via light self-action. Besides being connected with some very important aspects in the nonlinear matter-radiation interaction these effects can find several uses in optoelectronic devices. For this reason the primary interest is directed towards enhancing their efficiency by judicious choice of the nonlinear material. Up till now this effort has been concentrated on photoinduced level shifts and population changes to provoke rapid modifications of either the absorption or refraction indices of a medium in order to modify and control the longitudinal characteristics of the laser beam along its propagation direction. However equally important is to reach similar control on the transverse characteristics and in particular on the polarization state of an optical beam. We are interested in this problem and here we show that this can be achieved by the use of hybrid nonlinear optical processes that proceed via magnetooptical interactions. Such processes are of certain fundamental interest too but are in general weak and the main problem here is to enhance them by appropriate choice of the materials.
Renaissance of Optical Parametric Oscillators and Amplifiers
Authors: Tang C. L. , Pelouch W. , Powers P. , Kawasaki S.
Published: February 2023

Optical parametric oscillators (OPO) and amplifiers (OPA) are powerful solid state sources of broadly tunable coherent radiation capable of covering the entire spectral range from the near uv to the mid ir and can operate down to the femtosecond time domain with broad applications in research and industry. Although the principles of optical parametric processes have been well-known since the early days of quantum electronics, the development of practical optical parametric devices has been hampered by the lack of suitable nonlinear optical materials. As a result of recent advances in nonlinear optical materials research, there has been a resurgence of interest, and rapid progress, in the development and applications of optical parametric oscillators and amplifiers. The basic physics of the optical parametric process and recent results on the development and applications of practical optical parametric devices are reviewed in this talk.
Time-Resolved Measurements of Stimulated Brillouin Scattering Phase Jumps
Authors: Ottusch John J. , Mangir Metin S. , Jones D. Crispin , Rockwell David A.
Published: February 2023

Phase jumps are macroscopic manifestations of the noise that initiates and sustains a stimulated scattering process. We report the first time-resolved measurements of phase jumps in the Stokes beam produced by stimulated Brillouin scattering (SBS). The experimental results1 are in excellent agreement with the results of simple theoretical models2. Our measurements also led to the discovery of slow phase drifts and distinct frequency shifts in the Stokes beam. Phase jumps, phase drifts, and frequency shifts are properties common to oscillators that develop, without feedback, from noise.
Nonlinear Response of Metal Surfaces under Strong Femtosecond Laser Excitation
Authors: Gorokov S. V. , Koroteev N.
Published: February 2023

Summary not available at press time.
Microcavity QED Effects on a Diode Laser
Authors: Yamamoto Y. , Heitmann H. , Horowicz R. , Björk G. , Matinaga F. , Karlsson A.
Published: February 2023

Enhanced coupling of spontaneous emission into a single (lasing) mode in a semiconductor microcavity is expected to feature interesting new physics, such as an ultra-low threshold laser[1], lasing without inversion[2] and intensity squeezing at below the oscillation threshold[3]. Cavity QED effects which have been observed in various atomic systems, however, are not readily observed in semiconductor systems due to a very fast dipole dephasing time and broad, emission linewidth. Only exception is an excitonic emission at cryogenic temperatures. The spontaneous radiation pattern and lifetime were modified by monolithic semiconductor microcavities[4].
Optical Physics with Finesse - Dissipative Quantum Dynamics for Atoms in a Cavity with R=0.9999984
Authors: Kimble H. J. , Rempe G. , Thompson R. J.
Published: February 2023

While for the most part quantum statistical processes in quantum optics are investigated in a weak coupling regime, it has recently become possible to realize experimentally optical systems for which the internal coupling coefficient g is comparable to the external dissipative rates. Within this context the subject of our investigation is the quantum dynamical processes for a collection of N two-state atoms strongly coupled to a single mode of a high finesse optical cavity, Our particular experiment consists of a small collection of Cesium atoms (6S1/2, F = 4 → 6P3/2, F = 5 transition at 852nm) interacting with the TEM00 mode of a spherical mirror cavity. The critical technical advance for this work is the attainment of extremely low loss mirrors for high finesse (103 – 106) and hence long photon lifetime even in a small cavity.[1]
Spatial and Temporal Behaviors of Instabilities Generated by Counterpropagating Laser Beams in Rubidium
Authors: Blouin A. , Pinard M. , Maître A. , Rios Leite J. R. , Boyd R. W. , Grynberg G.
Published: February 2023

Pattern formation in nonlinear systems is a very active subject in many areas of physics. For example, in hydrodynamics the arrangement of the convective cells of the Rayleigh-Bernard instability [1] constitutes a model problem for pattern formation. In optics, important advances have been recently obtained in the case of lasers [2]. In contrast, transverse pattern formation in mirrorless optical passive systems [3] is no so wellknown because of the intrinsic complexity of a system without cavity and of the fact that the first experiments were done with pulsed lasers [4]. We present here results obtained with c.w. lasers and rubidium atoms. In particular, the relationship with hydrodynamics observations, suggests the possible existence of some general rule for pattern formation.
Generation of nonclassical states of the light by electro-optic nonlinear effects
Authors: Yuzhu Wang , Yongqing Li , Jiangping Yin
Published: February 2023

Optical nonlinearity is an important process for generating nonclassical states of the light such as squeezed states[1] and nonclassical correlation states [2]. We will demonstrate a new type of nonlinearity, electro-optic nonlinearity in a hybrid AOM device, for generating nonclassical states. The electro-optic nonlinearity in the hybrid devices has been widely used in the studies of optical bistability and chaos [3]. The main difference between the hibrid OB device and our squeezing AOM device is that in the OB case the feedback optic-electron signal is in relation to the intensity of the output light, but in the squeezing case the feedback signal is proportional to the photocurrent fluctution which is in relation to the quadrature phase fluctuation or to the intensity fluctuation of the output light.
Observation of large coherent nonlinearity caused by exciton-exciton interaction at exciton resonance in ZnSe
Authors: Saiki T. , Takeuchi K. , Kuwata-Gonokami M.
Published: February 2023

Excitonic nonlinearity in wide-gap semiconductors has a strong possibility that we can realize efficient ultrafast optical interactions. Recently, we have observed very large third-order nonlinear phase shift in ZnSe layers grown by MBE on GaAs substrate [1], The third-order nonlinear susceptibility at exciton resonance is more than 10–2 esu at 10 K. Because of the biaxial strain, the valence band splits into a heavy- and a light-hole branches at Γ point [2]. To clarify the intrinsic nature of excitonic nonlinearity, the materials which are free from such strain are preferable. In this report, we present our experiments on excitonic nonlinearity using ZnSe homoepitaxial layers which are free from the strain effects [3], and discuss the origin of enhanced nonlinearity at exciton resonance in ZnSe.
Thermal Effect and Deficient Match of Wavelengths in CW Single Frequency Laser SHG
Authors: Shao Zhongxing
Published: February 2023

There are a number of work on CW intracavity SHG is reported(1-4). Some of them are single frequency operation. However the conversion efficiency P(2ω)/P2(ω) in Ref. 1, 2. and 3 is much lower, even an order of magnitude, than in theoretical evaluation as well as the fundamental beam waists focused on the doublers are thicker in most of the reports than in the optimum focusing parameter given by Ref. 5. In addition our previous work(6), a beta barium borate (BBC) was located at the auxiliary waist ωopt designed to satisfy the optimum focusing parameter inside a CW single frequency ring dye laser cavity, showed also low efficiency. To look into the reasons we redo the experiments and find out it is thermal effect and deficient match of wavelengths that to abate the efficiency, to make the harmonic power can not go very high as well.
On a Possibility of Double Phase Conjugated Wave Generation in local responce media
Authors: Bel'dyugin I. M. , Bel'dyugina N. I. , Mel'kumov M. V. , Sviridov K. A.
Published: February 2023

The possible applications of double phase conjugation effect (DPC) such as optical computing, image processing and so on attracted investigators last few years. The realization of DPC was successfully fulfilled in photorefractive crystalls [1]. Meanwhile DPC in nonlocal responce media is seemed to be desirable due to considerable nonlinearities of some of such media. In addition these media are more available. However, when reflected waves were otained in experiments they were not phase conjugated [2]. In this work we treat conditions of phase conjugated wave generation in nonlocal responce medium.
Radiative Renormalization Analysis of Optical Double Resonance
Authors: Kelley P. L. , Blum O. , Gustafson T. K.
Published: February 2023

The problem of optical double resonance as shown in the Figure is a familiar one in optics.[1-3] In this case, a near-resonant field at frequency ν
l
connects level 1 with level 2 while a near resonant field at frequency v
u
connects level 2 with level 3. When level 2 is below level 3, the excitation of level 3 involves two photon absorption; if level 2 is above level 3, the excitation of level 3 is a Raman process.
Self Trapping of Optical Beams in Photorefractive Media
Authors: Segev Mordechai , Crosignani Bruno , Yariv Amnon
Published: February 2023

We present a new type of spatial solitons, which are due to the photorefractive (PR) effect of a medium(1). The shape of the soliton beam modulates the refractive index via the PR effect, which results in an exact compensation for the effects of diffraction, and causes the light beam to propagate with an unvarying profile. This index modulation is represented as a distribution of index gratings, each induced by the interference between two spatial (frequency) plane wave components of the light beam. Since the efficiency of this effect is independent of the absolute light intensity, these new solitons can be generated at very moderate light intensities. Moreover, a given soliton waveform can propagate unchanged in the medium, at very high or very low light intensities (and at all levels in between).
Guiding Light by Light Using Dark Spatial Solitons
Authors: Luther-Davies Barry
Published: February 2023

Reconfigurable waveguide structures will be the essential building blocks for an advanced, all-optical, photonics-based technology. In this context there is considerable interest in spatial solitons and their interactions to provide a means of switching and guiding beams in non-linear media1–4.
Self-Organizing Photorefractive Circuits
Authors: Anderson Dana Z. , Montgomery Don , Saffman Mark , Hermans Anno , Tuffli Andrea , Zhou Gan
Published: February 2023

Self-organization is a term often used to characterize physical systems that exhibit spatial or temporal pattern formation, particularly those system that are associated with phase transitions. Thus a freezing liquid that crystallizes at a lower temperature, a laser that breaks into coherent oscillation above threshold, and a magnetic spin glass that forms stable spatial patterns below a critical temperature can all be considered self-organizing systems. Self-organization is also used to refer to neural networks, real or artificial, that learn without a teacher, or some other form of supervisor, indicating what is to be learned. Self-organizing neural networks extract information from their input environment and subsequently process information according to their history. The processing behavior and capability of self-organizing networks are often remarkable as well as useful. Inspired by the work in network models, we have developed some photorefractive optical self-organizing systems that learn on their own to process information. While the information sense of self-organization is from neural networks, we have found that these systems also exhibit the properties of physical self-organizing systems. Phase transitions in physical systems are governed by some critical parameter, temperature in the case of a thermodynamic system, gain in the case of a laser, for example. In our systems, the critical parameter is the Shannon information entropy at the input: If the entropy is sufficiently low, then our systems will “freeze out” the information and process it in some useful way. If the entropy is above a critical value, then the system “melts” and can do nothing at all with the input. The critical information entropy depends on an optical nonlinear gain of the system.
Higher harmonics of the photorefractive grating under recording through the phase-locked detection mechanism
Authors: Dooghin A. V. , Ilinykh P. N. , Liberman V. S. , Mestiorkin O. P. , Zel’dovich B. Ya.
Published: February 2023

The photorefractive gratings may be used for holographic information storage and for other applications. The simplest hologram are recorded by sinusoidal interference pattern with intensity I(x,t)=Io+Io(m/2·exp{iqx}+c.c.), where Io is the total intensity of interacting waves, q is the spatial frequency of fringes, m is the contrast of interference pattern. If the contrast to approaches to 1 the sinusoidal form of holographic grating Is distorted by the recording of higher spatial harmonics.
Ultrafast Spectroscopy of Quantum Wells: Bridging the Gap Between Basic Physics and Devices
Authors: Shah Jagdeep
Published: February 2023

There is considerable current interest in optoelectronic devices such as lasers, detectors and modulators fabricated from semiconductor microstructures. One of the goals of the current work in these areas is to increase the speed of such devices. In order to accomplish increased operating speeds, it is necessary to understand limitations imposed by fundamental physics. Ultrafast spectroscopy of quantum wells provides a means of investigating fundamental physics that determines the ultimate physical limitation on device performance.
Magnitude and Evolution of Piezo-electric Nonlinearities in (111)-Oriented Strained Multiple Quantum Wells
Authors: McCallum D. S. , Cartwright A. N. , Boggess Thomas F. , Smirl Arthur L. , Moise T. S. , Guido L. J. , Barker R. C.
Published: February 2023

Extremely large optical nonlinearities have been predicted1 in strained quantum wells and superlattices composed of zincblende materials grown on substrates oriented in directions other than (100). In such materials, the strain produces a piezo-electric field along the growth direction, which Stark shifts the excitonic resonances to lower energies. The nonlinearity then arises from a blue shift of the exciton as this strain-induced field is screened by the redistribution of photogenerated charge within the quantum wells. Recently, the existence and screening of these fields has been demonstrated2,3 and the first measurements of the optical nonlinearity reported4. Specifically, in the latter studies4, optical nonlinearities were measured in In0.15Ga0.85As/GaAs multiple quantum wells oriented in the (211) direction that were approximately one order of magnitude larger than those of a similar structure grown in the (100) direction and roughly an order of magnitude larger than those previously reported in multiple quantum well structures.
Measurement of the Dispersion of n2 in Wide-Gap Materials from the IR to UV
Authors: Said A.A. , De Salvo R. , Ray B. , Sheik-Bahae M. , Hagan D.J. , Van Stryland E.W.
Published: February 2023

The recently published theory of Sheik-Bahae et al [1] predicts the dispersion of the nonlinear index of refraction in solids. In reference [1], the authors compared their theory with a large number of experimental data in which the dispersion of n2 was measured using the ratio of the incident photon energy and the energy gap of the solid, ħω/Eg. In most cases this ratio was chosen by using different materials which changes the energy gap and thus ħω/Eg. In this paper we directly determine the dispersion of n2 by measuring the nonlinear refractive index of the material at different laser wavelengths.
Instability and Routes to Chaos in Laser Diodes Due to External Optical Feedback
Authors: Kao Y.H. , Chen H.M.
Published: February 2023

It is well known that the semiconductor lasers, are susceptible to optical feedback from discrete interfaces or from distributed scattering such as in optical fiber medium. Feedback will affect the spectral property and the stability of the laser output. A number of dynamical behaviors, period doubling route, quasiperiodic route, and bistability, have been found[1–4]. In this letter we report the studies of routes to chaos of single mode laser diode output subjected to a variety of external cavity length. The studies of such effects are important not only for understanding of laser dynamical properties but also for applications of lasers in various systems.
Data Detection for Page-Access Optical Memories with Intersymbol Interference
Authors: Heanue John F. , Gürkan Korhan , Hesselink Lambertus
Published: February 2023

Page-access optical memories are being investigated for the next generation of digital storage due to their potential for simultaneously achieving high capacity, fast transfer rates, and short access times. Examples of such memories are systems based on volume holography[1], two photon 3D recording[2], and spectral hole burning[3]. A common feature of these systems is that data is input using a spatial light modulator (SLM) and the output signal is imaged onto a CCD array. A typical arrangement for a digital volume holographic memory is shown in Fig. 1. To meet the capacity and transfer rate goals of a commercial system, page sizes on the order of one million pixels are required. The need to image pixel-to-pixel from the SLM to the CCD array over such a large page imposes tight tolerances on the optical design. Deviations from ideal imaging typically result in degraded performance. In future systems, signal processing methods will be required to overcome the limitations of the optical components. We describe a technique for data detection in page-acces memories that extends the well-known method of sequence detection from digital communications to two dimensions. The technique, which we term Decision Feedback Viterbi Algorithm (DF-VA) Detection improves the bit-error-rate (BER) performance of systems without ideal optics. Use of such a detection scheme can allow the use of less expensive, lower-complexity imaging optics, or, alternatively, can lead to higher information density per data page.
Novel Azo-Dye Doped PMMA Films as Optical Data Storage Media
Authors: Pham V. P. , Granger A. , Galstyan T. , Lessard R. A.
Published: February 2023

Optical information was holographically stored, retrieved, erased and overwritten on new azo-dye doped PMMA guest-host films. The information is stored in the form of highly localized dichroism and birefringence of the polymer films, induced by spatially modulated polarization and intensity of writing light. In this paper, we are presenting new data concerning the dynamic behaviour of these films. We have also investigated the effect of the intensity of the reading beam on the storage time of these polymeric systems.
Storage and readout of high resolution holographic images for optical data storage and security applications
Authors: Sayano Koichi , Zhao Feng
Published: February 2023

One of the major challenges with high density holographic data storage is readout of the data, which by necessity is comprised of high resolution features, onto the detector array.1 With minimum feature size of 10 μm or less being proposed for high data capacity, the optical system resolution requirement is approaching the diffraction limit of available optics. Low f-number, high line resolution, 1:1 magnification, wide field of view optics is extremely expensive, but necessary to image large, high resolution arrays of data from proposed holographic memory devices. Recently, we applied optical phase conjugation in the holographic recording process to correct for Fresnel diffraction and image aberration during readout, eliminating the need for the bulky and expensive optical imaging system.2
"Holographic Digital Storage Beyond the Diffraction Limit. Is It Possible? Conceptual Analysis of Holographic Digital Storage with Synthetic Aperture"
Authors: Morozov Valentine
Published: February 2023

Holographic digital storage is a promising technology for a Tbit memory with fast access time. Nevertheless, a competition with magnetic storage in terms of storage capacity remains strong due to continuing progress in magnetic storage development. New innovative ideas are needed to increase holographic storage capacity beyond the limits imposed by diffraction limits.
Bose Einstein Condensation
Authors: Cornell Eric
Published: February 2023

Summary not available.
Measurements of the Nonlinear Phase Shift from Orthogonally Polarized Solitons Collisions
Authors: Koehler S.D. , Kutz J. N. , Leng L. , Bergman K.
Published: February 2023

As bitrates in communications and computing systems continue to increase, a demand is created for ultrafast time domain demultiplexing (TDM) components. Much research has recently concentrated on interferometric fiber optic switching, and many of the devices consist of fiber loop mirrors, relying on a non-linear phase shift to induce the switching [1-4]. However, the %(3) nonlinearity of fibers is extremely weak long interaction lengths have been a source of severe latency. In order to reduce these latencies, it is desirable to induce large non-linear phase shifts in relatively short fiber lengths without significantly distorting the temporal pulse shape or its spectrum. We present analysis and experiments of a switching scheme based on a collision between two orthogonally-polarized soliton pulses in a highly birefringent polarization-maintaining (PM) optical fiber.
Tailoring Nonlinear Optical Interactions with Microstructured Materials
Authors: Fejer M.M.
Published: February 2023

Microstructured ferroelectrics and semiconductors offer unprecedented flexibility in tailoring nonlinear materials to suit specific applications. Quasi-phasematching in conventional periodic structures, as well as in axially and transversely modulated structures, will be discussed.
Midinfrared Femtosecond Pulse Generation Using a 250 kHz Ti:Sapphire pumped BBO OPA and DFG in AgGaS2
Authors: Reed Murray K. , Steiner-Shepard Michael K.
Published: February 2023

Extending the tuning range of Kerr lens modelocked Ti:sapphire lasers into the visible, ultraviolet and near infrared by using ultrafast optical parametric amplifiers (OPA) is now common. A high power source of sub-picosecond light pulses tunable to longer wavelengths in the midinfrared is attractive for applications in the ultrafast spectroscopy of molecular vibrations and intersubband absorption in semiconductors. In this talk we describe a low energy 800 nm pumped, BBO Type-II infrared OPA and demonstrate the conversion of the output of this OPA through difference frequency generation (DFG) in AgGaS2 to the midinfrared from 2.4 μm to beyond 12 μm with more than 10 mW of power from 3 μm to 6 μm.
Compensating Primary Mirror Distortions in Astronomical Telescopes with Real-Time Holography
Authors: Gruneisen Mark T. , Peters Kevin , Deaton Terrence F.
Published: February 2023

Conventional telescope imaging systems are prone to image degradation resulting from several distorting mechanisms. These mechanisms include atmospheric turbulence, misalignment of telescope optics and primary mirror distortions. Furthermore, engineering challenges associated with fabricating, transporting and manipulating large-aperture optics limit the size of high-optical-quality primary mirrors manufactured for telescope systems. This in turn limits both the resolution and light gathering ability of present day ground-based and space-based astronomical telescopes.
Tunneling Spectroscopy for Quantum Well Excitons
Authors: Cao H. , Klimovitch G. , Björk G. , Pau S. , Yamamoto Y.
Published: February 2023

The conventional photoluminescence (PL) spectroscopy can not measure the exciton binding energy directly since the exciton PL peak only gives the value of the bandgap energy minus the exciton binding energy, i. e. Ec − Ev −Eex, where Ec (Ev) is the energy of the conduction (valence) band edge, and Eex is the exciton binding energy. Recently we have observed a new phenomenon: the direction creation of excitons in a GaAs quantum well (QW) by hole assisted electron resonant tunneling. We will show that this new tunneling process as well as its reverse process can be a new technique to measure directly the exciton binding energy.
Frequency Doubled External Cavity Diode Lasers for Spectroscopy Applications
Authors: Bortz M. L. , Day T. , Fejer M. M. , Wang W.
Published: February 2023

Laser spectroscopy, long the domain of the dye laser, is experiencing a renaissance due to the development of tunable, higly coherent, external cavity diode lasers (ECDL’s). Such lasers have been used extensively as sources for precision spectroscopy experiments. Recently, ECDL’s have become commercially available, sparking interest in the development of diode laser based sensors for many industrial and process control applications. One particular class of applications involves the sensing of atoms during the growth of thin films. Many atoms have strong ground state absorption lines between 380-420 nm, a wavelength range that is fortuitously at 1/2 the output wavelength of mature GaAs based diode laser technology and accessible with either LiNbO3, LiTaO3, and KTP QPM-SHG waveguides. The marriage of ECDL’s and nonlinear quasi-phasematched second harmonic generation waveguide allows the generation of tunable, highly coherent radiation in the blue-UV spectral range required for atomic absorption spectoscopy. Furthermore, the low power levels and ~ 10 GHz tuning ranges required for atomic absorption spectroscopy are readily achievable with ECDL’s and QPM-SHG waveguides. Atomic absorption spectrosocpy can yield information about the deposition process and can be used to monitor and control the film growth rate. In this presentation we review the development of frequency doubled ECDL’s and applications to the material synthesis of aluminum and titanium films.
Second Harmonic Generation Studies of Porous Ice Films: Quantitative Measurements of Multilayer Physical Adsorption On Heterogeneous Surfaces
Authors: Robinson Jeanne M. , Henson Bryan F. , Wilson Kevin R.
Published: February 2023

We present nonlinear light scattering measurements of the equilibrium, multilayer adsorption of molecular species on polycrystalline, porous ice films. The adsorption spectra are quantitatively modeled with the multilayer physical adsorption theory of Brunauer, Emmett and Teller (BET) and an extension based on the Bragg-Williams (BW) formalism which incorporates adsorbate-adsorbate interactions within the first layer. Although the polycrystalline, heterogeneous ice surfaces are likely characterized by adsorption site distributions broad both in energy and the size of local, homogeneous domains, these simple parameterizations model the data to high precision and imply a reduction in the effective complexity of the interface. The ability to quantitatively model adsorption onto a topologically complex, heterogeneous substrate from first principles renders many important systems amenable to quantitative study. For example, we have shown recently [1] that the physical adsorption of H2O as islands on model polar stratospheric ice surfaces may be a controlling factor in the rates of some surface mediated chemical reactions important in seasonal ozone depletion.
Two-color Photorefractivity in LiNbO3 Waveguides
Authors: Eger D. , Arbore M. A. , Fejer M. M. , Bortz M. L.
Published: February 2023

Short wavelength coherent light sources are required for applications such as process monitors and fluorescence based instruments. QPM waveguides can be used to frequency double GaAlAs diode laser output for this purpose. However the efficiency of chemically poled waveguides of different ferroelectric crystals such as LiNbC3, LiTaO3 and KTiOPO4 degrade as the generated wavelength approaches the UV spectral range. The degradation is characterized by a decrease in the peak doubling efficiency, broadening of the QPM curve and reduction in the IR transmissivity of the waveguide. The damage increases with the intensity of the SH wave, limiting the power which can be generated by these waveguides. There is limited information in the literature on the degradation mechanism. The presence of the two waves in the waveguides and the strong variation of the SH power along the waveguide give rise to complex dependence of the output power with time, input IR power and wavelength that is difficult to characterize with SHG measurements alone.
Ultrafast Time-Resolved Ellipsometry of Four-Wave-Mixing Signals: Measurement of Coherent Nonlinear Processes in Semiconductors
Authors: Smirl Arthur L. , Paul A. E. , Bolger J. A.
Published: February 2023

Temporally and spectrally-resolved degenerate four-wave-mixing (FWM) techniques have been enormously successful in providing new information about fundamental nonlinear and coherent optical processes in atomic, molecular and solid state systems. Typically, in such studies, the time-integrated or time-resolved magnitude of the FWM emission (or its spectrum) is studied as a function of the input parameters (such as the fluence, time delays or the polarization states of the incident pulses), but the polarization state of the FWM signal itself has been largely ignored. Moreover, the few attempts that have been made to determine the polarization state of the FWM emission have been restricted to measuring the direction of polarization, but they have left the ellipticity and the degree to which the signal is unpolarized unspecified.
Photorefractive Optical Nonlinearities
Authors: Glass A. M.
Published: February 2023

The photorefractive effect is well suited to optical image processing. The talk will emphasize the optimization of the speed and sensitivity of photorefractive materials.
Nonlinear Optical Properties of Selectively Contacted Gallium Arsenide Doping Superlattices
Authors: Tobin M. S. , Pennise C. A. , Bruno J. D. , Hasnain G.
Published: February 2023

The modulation of absorption in GaAs doping superlattices (DSL’s) has been previously demonstrated using optical excitation.1–3 By using selective contacts to the n- and p-type layers, Chang-Hasnain et al.4 demonstrated the tunability of the optical absorption by means of electrical bias. In this paper, we show experimental results whereby the optical modulation of the optical properties is examined as a function of the applied electrical bias. From modulated transmission and reflection data, changes in the real and imaginary parts of the refractive index are determined. Additionally, we have examined the recovery time of the DSL following picosecond laser illumination and show that it is substantially decreased with the use of an external circuit.
Third-Order Optical Susceptibility in n-i-p-i GaAs Arising from Nonparabolic Electronic Subbands
Authors: Choquette Kent D.
Published: February 2023

Semiconductor superlattices allow the development of materials with enhanced nonlinear optical characteristics over those found in bulk semiconductors. For both doping and compositional superlattices a one-dimensional periodic potential is introduced which modifies the electronic energy band structure. This paper reports the investigation of the optimization of nonparabolic subbands in compensated short-period GaAs doping superlattices for enhancement of a nonresonant third-order optical susceptibility. This nonlinear phenomenon would be useful for nonlinear optical applications requiring long wavelengths or wavelength insensitivity.
Asymmetric Quantum Well Structures Possessing Large Second Order Optical Nonlinearities
Authors: Khurgin J.
Published: February 2023

Nonlinear optical properties of quantum wells (QW’s) and superlattices (SL’s) 1,2 are attracting increasing interest. Calculations and observations of strong third-order nonlinearities were reported in GaAs-GaAlAs QW and SL structures. Among the phenomena mentioned as leading to large values of x(3) in such structures are conduction band nonparabolicity 3,4, exciton line saturation 5 and the quantum confined Stark effect (QCSE) 6,7. Practical devices using QCSE, the so-called self-electrooptic effect devices, or SEED’s have been successfully demonstrated 8.
Large Optical Nonlinearities in Hybrid Semiconductor Devices
Authors: Jäger Dieter
Published: February 2023

In hybrid semiconductor devices artificial optical nonlinearities can occur as a result of combined optoelectronic and electro-optical effects. The principle of such a two-step process is discussed in detail where basic structures as shown in Fig. 1 are considered. In particular, the device is assumed to exhibit firstly the properties of an optoelectronic photodetector, where optical power is absorbed to generate a photocurrent. Secondly, it is assumed that the same device simultaneously behaves as a modulator, where electrical signals control the optical output by using some electro-optical mechanisms. Obviously, both properties are coupled by the photocurrent which finally leads to a self-interaction process. As a result, a self-electro-optic effect occurs giving rise to an effective optical nonlinearity according to the following scheme As can be seen, an artificial optical nonlinearity is obtained which can electrically, i. e. externally be controlled.
Twenty-Five Years of Nonlinear Optics
Authors: Bloembergen Nicolaas
Published: February 2023

Summary not available.
Electro-optic Properties of Polyvinylidene Fluoride-Trifluoroethylene
Authors: Berry M.H. , Gookin D.M. , Jacobs E.W.
Published: February 2023

The polymer, polyvinylidene fluoride (PVF2), has been primarily investigated because of its applications to transducers.1 Electrical measurements showed that both PVF2 and copolymers of PVF2 with trifluoroethylene(TrFE) are ferroelectric.2,3 The electro-optic effect in PVF2 has linear and quadratic components which are related to its dielectric hysteresis.4 The spontaneous polarization in PVF2-TrFE copolymers is larger than in the homopolymer and the dielectric hysteresis is more pronounced. In this study we investigated the electro-optic properties of PVF2 copolymerized with 32% TrFE. We demonstrate in-phase and out-of-phase intensity modulation with this material.
Characterization of Photo-Induced Absorption in BaTiO3
Authors: Brost G.A. , Motes R.A. , Kroncke G. Thomas
Published: February 2023

Recent experimental and theoretical results indicate that the photorefractive properties of barium titanate are influenced by the presence of secondary photorefractive centers.1-4 These are traps which are highly ionized at room temperature but can become populated by illumination with light. We have also attributed an intensity-dependence in the absorption coefficient to these traps.4 In this paper we study the secondary photorefractive centers by measuring the spectral and temporal characteristics of the photo-induced absorption.
Effects of Oxygen Partial Pressure on Optical Properties of VO2
Authors: Razavi A. , Hughes T.
Published: February 2023

Vanadium dioxide is known to undergo a first order phase transformation at approximately 67°C. In its low temperature state (T<67°C) VO2 has a monoclinic structure, is semiconductive, and exhibits high transmission of a range of IR wavelengths. At temperatures greater than 67°C VO2 reverts to a tetragonal structure, becomes conductive, and exhibits high reflectance.1 The absorption coefficient of VO2 is relatively high below one micron2 and above thirteen microns3; therefore, changes in the optical properties of VO2 can be used most effectively between these wavelengths.
Second Harmonic Generation in β-Barium Borate using Elliptical Focussing
Authors: Freegarde T.G.M. , Coutts J. , Corney A.
Published: February 2023

Elliptical focussing can be used to enhance SHG efficiency significantly in highly birefringent media such as β-barium borate.
Cross-phase Modulation and Induced-focusing of Optical Nonlinearities in Optical Fibers and Bulk Materials
Authors: Alfano R. R. , Baldeck P. L. , Ho P. P.
Published: February 2023

Cross-phase modulation (XPM) and induced-focusing occur when copropagating ultrafast pulses interact in a nonlinear Kerr medium.1-16 XPM effects are being investigated as a new technique to control with femtosecond time response the spectral, temporal and spatial properties of ultrafast pulses. This talk will review our most recent results obtained on XPM and induced-focusing in optical fibers and bulk materials.
Intrinsic Brillouin Linewidths and Stimulated Brillouin Gain Coefficients in Glasses studied by Inelastic Light Scattering
Authors: Schroeder John , Hwa Luu–Gen
Published: February 2023

Rayleigh–Brillouin scattering measurements on various multicomponent halide glasses and some selected oxide glasses were done. The Brillouin linewidth measurements, the Brillouin intensities and frequency shifts allowed the calculation of phonon attenuation, Pockels' elastooptic coefficients and the Stimulated Brillouin scattering gain coefficients. Brillouin linewidths obtained experimentally range between the limit of 52MHz for a BeF2 glass and 213MHz for a Zirconium–Barium–Lanthanium–Fluoride glass.1 The parameter obtained in the above study shows that the threshold power for the onset of Stimulated Brillouin scattering in some halide glasses is greater than that for silicate glasses, which has important ramifications as a selection criterion for halide based glasses as single mode optical waveguide materials.2
Nonlinear Absorption and Power Limiting in Waveguides
Authors: Han Sang K. , Zhenguang H. , Srivastava R. , Ramaswamy R.V.
Published: February 2023

Nonlinear waveguides are considered to be potential candidates for all-optical signal processing applications if suitable substrate/film materials can be identified. The material parameters of primary interest are the nonlinear coefficient n2, the absorption coefficient α and the relaxation time τ [1]. For fast switching with low power requirements, n2/ατ should be as large as possible. Although several different materials have been explored, the quantum-confined nonlinearity such as observed in multiple quantum wells and in microcrystallites of II-VI semiconductor-doped glasses appears to be very attractive. However, in such materials near-band gap enhancement of the nonlinearity is accompanied by absorption and consequent heating of the substrate. The thermal effect is much slower than, for example, the band-filling fast (ps) nonlinearity in doped glasses and consequently it is likely to interfere in high-speed operation of nonlinear devices unless it can be isolated. Thus it is important that its magnitude and role be understood. In this paper, we present measurement of temperature dependence of refractive index and spectral transmission and explain the power limiting observed in planar and channel waveguides in II-VI doped glasses. The results are analyzed on the basis of thermal effects associated with the absorption and the consequent red-shift of the band-edge in the bulk glass. Our quantitative analysis explains not only the nonlinear prism coupler data of other authors [2,3], but also is in excellent agreement with our results of power limiting in planar and channel waveguides [4].
Transient Optical Nonlinearities in Multiple Quantum Well Structures: Four Wave Mixing, Anisotropic Carrier Diffusion and the Quantum Confined Stark Effect
Authors: Miller A. , Manning R. J.
Published: February 2023

Multiple quantum well (MQW) semiconductors can exhibit a number of nonlinear optical phenomena associated with the clearly resolved, room temperature excitons. These are of practical interest for optically bistable devices, mode-locking of semiconductor lasers and phase conjugation. For instance, refractive nonlinearities associated with the saturation of the exciton can be very sensitive [1]. The quantum confined Stark effect can also be employed to produce optical nonlinearities at low power [2,3].
Phonon-Mediated Optical Nonlinearities in Polydiacetylene
Authors: Greene B.I. , Mueller J.F. , Orenstein J. , Rapkine D. , Schmitt-Rink S. , Thakur M.
Published: February 2023

Organic molecules and polymers have long been known to exhibit large values of the third-order susceptibility, χ(3). However, in spite of many investigations, the mechanisms governing the nonlinear optical response of these materials are not well understood. Recently, tremendous progress in two related areas has made this problem ripe for further examination. Intense study of polyacetylene and related materials has led to a more complete understanding of the ground state and elementary excitations of conjugated polymer chains,1 while studies of quasi-2D inorganic semiconductors, notably GaAs-AlGaAs multiple quantum well structures (MQWS), have highlighted the importance of reduced dimensionality for optical nonlinearity.2 In this work we have extended the experimental and theoretical approach recently applied in MQWS to quasi-1D polydiacetylene, with unusual and novel results.
Optical Nonlinearities of Polymers
Authors: Prasad Paras N.
Published: February 2023

This talk will include selective results from our comprehensive program in nonlinear optical effects in organic molecules and polymers. We have calculated microscopic nonlinearities of organic molecules in several series of conjugated structures using ab-initio SCF approach coupled with the finite field method. The effects of increase in the II - electron conjugation length, molecular conformation, heavy atom effect and the role of substitutes have been investigated in order to derive an understanding of molecular structure-property relation so that structural parameters associated with enhanced optical nonlinearities can be identified. This theoretical study has been complemented with the measurements of optical nonlinearities in sequentially built and systematically derivatized structures.
Resonant Third-Order Nonlinearity of Quasi One- and Zero-Dimensional Electron Systems
Authors: Blau W. , Byrne H. , Horan P.
Published: February 2023

The invention of semiconductor multi-quantum wells and the following discovery of large optical nonlinearities in them [1] have started a substantial research effort into the properties of such two-dimensional quantum confined systems. Furthermore the question of further reducing the electron dimensionality and the associated scaling laws [2] has arisen. By reducing the electron dimensionalities by confining them physically in two and three dimensions beyond their de-Broglie wavelength, the situation of the idealized "particle-in-the-box" is realized. Associated with this behavior is an increase in the exciton binding energy (observable at room temperature) and in oscillator strength, and hence also an increase of the optical nonlinearity arising from the saturation of this transition. By suitable choice of chemical systems this low dimensional behavior can be experimentally approached.
Nonlinear Optical Properties of Semiconductor Composite Materials
Authors: Li Y. Q. , Sung C. C. , Inguva R. , Bowden C. M.
Published: February 2023

Nonlinear optical properties of composites have drawn much attention recently due to anticipation that the desired optical properties may be manipulated by the parameters such as the volume fraction of the constituents and the size of the microstructures which consist of nonlinear material1,2. The small size of the microstructure may reduce the relaxation time, and increase the speed of the device fabricated from such materials. Dielectric and quantum confinement may also drastically enhance the effective optical nonlinearity. In order to properly address the problem, one has to obtain the effective dielectric function for the composite material for which methods are, fortunately, already available in the literature. We use the self-consistent field approximation3. One must also treat the local field correction, as a result of which the propagation of the field becomes more complicated. Some aspects of these problems have been addressed earlier in the literature, e.g., the local field effect in combination with the effective medium theory has been done for the water drop by Leung4. However, most of the earlier work in the literature is essentially in the framework of the mean-field approximation1 which, as will be shown, is only valid in the small absorption limit.
Reverse Saturable Absorbers: Indanthrone and Its Derivatives
Authors: Stetyick K. A. , Hoffman R. C. , Potember R. S.
Published: February 2023

Indanthrone has been shown to exhibit the phenomenon of reverse saturable absorption.1 We have synthesized several derivatives of the parent compound which have proved to be more efficient reverse saturable absorbers than the indanthrone itself.
Potassium Titanyl Phosphate (KTP) Properties and New Applications
Authors: Bierlein J.D.
Published: February 2023

KTP is a superior material for various nonlinear optical applications including second harmonic generation of the Nd:YAG 1.06 micron laser1. It is not hydroscopic, has large nonlinear optic coefficients and high damage thresholds, has small beam walkoff, and has large thermal and angular bandwidths. In addition KTP has large electrooptic coefficients and low dielectric constants which make it potentially useful for electrooptic applications.2 It has the largest optical waveguide modulator figure-of-merit of any known inorganic material.
The Evolution of Electromagnetic Amplifiers Over Time, Frequency, and Application
Authors: Jacobs Ira
Published: February 2023

Nineteenth (twentieth) century electrical (optical) communications were
generally constrained to the mechanical (electronic) control of
electricity (lighwaves). Parallels in the evolution of electronic and
optical amplifiers are discussed.
0.98-μm Laser Diode Pumped Erbium-Doped Fiber Amplifiers with a Gain Coefficient of 7.6 dB/mW
Authors: Shimizu Makoto , Yamada Makoto , Takeshita Tatsuya , Horiguchi Masaharu
Published: February 2023

Laser diode pumped erbium-doped fiber amplifiers (EDFA) have high potential for optical pre- and booster-amplifiers in 1.5μm optical communication systems(1)(2). To date, three kinds of LD, with wavelengths of 0.81μm, 0.98μm, and 1.48 μm, have been studied as pumping light sources. From among these, the 0.98 μm LD pumped EDFA demonstrated the highest gain coefficient and the lowest noise characteristics(3)(4). We reported that a highly efficient EDFA with a gain coefficient of 4.9 dB/mW could be fabricated by taking account of the erbium concentration effect(5)(6)