bluuebunny/crossref_metadata_2025 huggingface dataset:
Inteligencia emocional: Un estudio del TEIQue-SF aplicado a líderes potenciales en el ámbito universitario.
Authors: Coronado-Maldonado Isabel , Díaz-Muñoz Rocío , González-Sodis José Luis
Published: February 2023

La inteligencia emocional está cobrando cada más más relevancia en multitud de ámbitos y también en el empresarial. Este protagonismo actual motiva que a que diferentes corrientes de trabajo sugieran la idea de que la inteligencia emocional es un factor importante para un liderazgo efectivo en las organizaciones. Nuestro trabajo encaminó su estudio hacia el análisis de la inteligencia emocional del alumnado universitario por dos motivos: por un lado, la tarea de la dirección es una labor compleja, tanto por las funciones desarrolladas en sí mismas, como por las habilidades y requisitos que se necesitan. Por otro lado, el alumnado universitario, concretamente aquél relacionado con los estudios de dirección de empresas, puede verse potencialmente involucrado en futuros procesos de selección para la ocupación de puestos de responsabilidad. El proceso llevado a cabo para conocer el grado de tal inteligencia, para predecir sus capacidades de liderazgo y sus posibilidades de adecuación a roles de relevancia, se ha instrumentado a través de una adaptación del cuestionario de Autoinforme de Petrides en su forma corta. Del mismo modo, se ha buscado identificar las principales dimensiones que configuran la inteligencia emocional, partiendo de una inicial propuesta de investigación de dicho autor. Los resultados encontrados en cuanto a la autovaloración de alumnos universitarios muestran un error estándar de la media muy pequeño, entendiéndose que las respuestas recogidas son bastante acertadas con respecto a la realidad. Por lo tanto, como conclusión, en las cuestiones planteadas en cuanto a la autovaloración de competencias e inteligencia emocional para asumir puestos de responsabilidad, se puede afirmar que el alumnado muestra un nivel de inteligencia emocional medio-alto. Esto refleja una tendencia clara a ofrecer un alto nivel de evaluación de sí mismos, dando muestra de un significativo nivel de autoconfianza y seguridad. Además, entre las consideraciones finales se han sugerido diferentes posibles líneas de investigación futuras, buscando alternativas que permitan implementar medidas para paliar la subjetividad en las apreciaciones, a través de los propios cuestionarios o el diseño de las preguntas, o proponiendo diseñar nuevas metodologías didácticas que permitan desarrollar las dimensiones de la inteligencia emocional del alumnado identificadas a través de este estudio.
Around The Regions: The South West
Authors: Tulip Stephen
Published: February 2023

A recent study has found that the public opinion is that we ‘don’t make anything in the UK any more’. The reality, of course, is a long way from that, say EEF, the manufacturers’ organisation, in their latest column
EVALUATING PELVIC TILT USING MEASUREMENTS FROM ANTEROPOSTERIOR PELVIC RADIOGRAPHS: A META-ANALYSIS OF SACRO-FEMORAL-PUBIC (SFP) METHOD
Authors: Chai Y. , Khadra S. , Boudali A.M. , Darwish I. , Walter W.L.
Published: February 2023

Accurate measurement of pelvic tilt (PT) is critical in diagnosing hip and spine pathologies. Yet a sagittal pelvic radiograph with good quality is not always available. Studies explored the correlation between PT and sacro-femoral-pubic (SFP) angle from anteroposterior (AP) radiographs yet demonstrated conflicting conclusions about its feasibilities. This study aims to perform a cohort-controlled meta-analysis to examine the correlation between the SFP angle and PT and proposes an application range of the method.

This study searched PubMed, Embase, Cochrane, and Web of Science databases for studies that evaluated the correlation between SFP angle and PT. The Pearson's correlation coefficient r from studies were tabulated and compared. Pooled r for overall and gender/age (teenage or adult) controlled subgroup were reported using Fisher's Z transformation. Heterogeneity and publication bias were evaluated using Egger's regression test for the funnel plot asymmetry.

Eleven studies were recruited, with nine reported r (totalling 1,247 patients). The overall pooled r was 0.61 with high inter-study heterogeneity (I2 = 75.95%). Subgroup analysis showed that the adult group had a higher r than the teenage group (0.70 versus 0.56, p < 0.001). Although statistically insignificant (p = 0.062), the female group showed a higher r than the male group (0.72 versus 0.65).

The SFP method must be used with caution and should not be used in the male teenage group. The current studies did not demonstrate that the SFP method was superior to other AP landmarks correlating to PT. Identical heterogeneity was observed among studies, indicating that more ethnicity-segregated and gender-specific subgroup studies might be necessary. More data input analysing the errors will be useful.
Digital labeling for 3D histology: segmenting blood vessels without a vascular contrast agent using deep learning
Authors: Lapierre-Landry Maryse , Liu Yehe , Bayat Mahdi , Wilson David L. , Jenkins Michael W.
Published: February 2023

Recent advances in optical tissue clearing and three-dimensional (3D)
fluorescence microscopy have enabled high resolution in
situ imaging of intact tissues. Using simply prepared
samples, we demonstrate here “digital labeling,” a
method to segment blood vessels in 3D volumes solely based on the
autofluorescence signal and a nuclei stain (DAPI). We trained a
deep-learning neural network based on the U-net architecture using a
regression loss instead of a commonly used segmentation loss to
achieve better detection of small vessels. We achieved high vessel
detection accuracy and obtained accurate vascular morphometrics such
as vessel length density and orientation. In the future, such digital
labeling approach could easily be transferred to other biological
structures.
Investigations of nonlinear polarization transfer between obliquely intersecting beams
Authors: Schmitz Holger , Trines Raoul , Bingham Robert , Kur Eugene , Michel Pierre
Published: February 2023

Electromagnetic waves propagating through plasma can interact nonlinearly through a variety of different mechanisms. The excitation of a plasma beat wave (ions or electrons) can create a refractive index modulation that changes the dispersion of the interacting beams. Alternatively, high-intensity beams can enter the regime where relativistic nonlinearities influence the propagation dynamics. In recent studies [Opt. Express 29, 1162 (2021)OPEXFF1094-408710.1364/OE.413064], it was proposed that two beams propagating along the same axis can exchange their polarization state due to nonlinear interaction. Here we present a numerical analysis of two laser beams intersecting in a nonlinear medium at varying angles. Polarization transfer is observed as predicted by analytical theory for a range of angles. For small angles, it is found that filamentation of the interacting beams becomes important. Analytical estimates of the filamentation threshold are presented, and good agreement is found with the simulation data.
Femtosecond long-wave-infrared generation in hydrogen-filled hollow-core fiber
Authors: Chen Yi-Hao , Moses Jeffrey , Wise Frank
Published: February 2023

Femtosecond long-wave-infrared (LWIR) pulses have found applications in several fields, but their generation is limited to CO2 lasers and solid-state frequency converters. Waveguide-based Raman red shifting provides another promising solution to efficiently generate LWIR pulses. Here, we numerically study LWIR pulse generation in a hydrogen-filled hollow-core fiber. Several excitation schemes are considered, involving one or two pulses at either the same or different wavelengths. The analysis reveals that a waveguide structure enables tailoring of the Raman gain, which is required to produce pulses at LWIR wavelengths. With ∼5-mJ and 50-fs input pulses, clean 400-µJ and 88-fs pulses at 12 µm are theoretically generated with 41% total quantum efficiency. The simulations also provide insight into the nonlinear dynamics of the Raman gain, where the concept of a phonon amplifier underlies the optimal performance that can be achieved. Only the two-pulse scheme with a two-color source creates a good phonon amplifier for efficient LWIR generation.
Nonlinear operation of an FP laser with PT symmetry active medium
Authors: Mossakowska-Wyszyńska Agnieszka , Witoński Piotr , Szczepański Paweł
Published: February 2023

In this paper, an analysis of the nonlinear laser operation in an active medium made of a parity time (PT) symmetric structure placed in a Fabry-Perot (FP) resonator is demonstrated for the first time. The FP mirrors’ reflection coefficients and phases, the PT symmetric structure period, primitive cell number, and the gain and loss saturation effects are taken into account in a presented theoretical model. The modified transfer matrix method is used to obtain characteristics of laser output intensity. Numerical results show that the selection of the appropriate phase of the FP resonator’s mirrors makes it possible to obtain different levels of the output intensity. Moreover, for certain value of a ratio of the grating period to the operating wavelength, it is possible to obtain the bistability effect.
Focusing light with a metal film coated patchy particle
Authors: Xu Chu , Ye Ran , Zou Pengxin , Yang Tianyu , Melinte Sorin , Wang Zengbo , Zuo Chao
Published: February 2023

Microsphere-assisted super-resolution imaging is a promising technique that can significantly enhance the resolution of conventional optical microscopes. The focus of a classical microsphere is called photonic nanojet, which is a symmetric high-intensity electromagnetic field. Recently, patchy microspheres have been reported to have superior imaging performance than pristine microspheres, and coating microspheres with metal films leads to the formation of photonic hooks, which can enhance the imaging contrast of microspheres. Understanding the influence of metal patches on the near-field focusing of patchy particles is important for the rational design of a nanostructured microlens. In this work, we theoretically and experimentally showed that the light waves can be focused and engineered using patchy particles. When coating dielectric particles with Ag films, light beams with a hook-like structure or S-shaped structure can be generated. Simulation results show that the waveguide ability of metal films and the geometric asymmetry of patchy particles cause the formation of S-shaped light beams. Compared with classical photonic hooks, S-shaped photonic hooks have a longer effective length and a smaller beam waist at far-field region. Experiments were also carried out to demonstrate the generation of classical and S-shaped photonic hooks from patchy microspheres.
Quartz tuning fork-based high sensitive photodetector by co-coupling photoelectric and the thermoelastic effect of perovskite
Authors: Lou Cunguang , Dai Jialiang , Wang Yaxin , Zhang Yu , Li Yifan , Liu Xiuling , Li RuiKai , Ma YuFei
Published: February 2023

This paper reports a new strategy for enhancing the photoresponse of a quartz tuning fork (QTF). A deposited light absorbing layer on the surface of QTF could improve the performance only to a certain extent. Herein, a novel strategy is proposed to construct a Schottky junction on the QTF. The Schottky junction presented here consists of a silver-perovskite, which has extremely high light absorption coefficient and dramatically high power conversion efficiency. The co-coupling of the perovskite's photoelectric effect and its related QTF thermoelastic effect leads to a dramatic improvement in the radiation detection performance. Experimental results indicate that the CH3NH3PbI3-QTF obtains two orders of magnitude enhancement in sensitivity and SNR, and the 1σ detection limit was calculated to be 1.9 µW. It was the first time that the QTF resonance detection and perovskite Schottky junction was combined for optical detection. The presented design could be used in photoacoustic spectroscopy and thermoelastic spectroscopy for trace gas sensing.
Precise measurement of microwave polarization using a Rydberg atom-based mixer
Authors: Wang Yuhan , Jia Fengdong , Hao Jianhai , Cui Yue , Zhou Fei , Liu Xiubin , Mei Jiong , Yu Yonghong , Liu Ya , Zhang Jian , Xie Feng , Zhong Zhiping
Published: February 2023

A Rydberg atom-based mixer has opened up a new method to characterize microwave electric fields such as the precise measurement of their phase and strength. This study further demonstrates, theoretically and experimentally, a method to accurately measure the polarization of a microwave electric field based on a Rydberg atom-based mixer. The results show that the amplitude of the beat note changes with the polarization of the microwave electric field in a period of 180 degrees, and in the linear region a polarization resolution better than 0.5 degree can be easily obtained which reaches the best level by a Rydberg atomic sensor. More interestingly, the mixer-based measurements are immune to the polarization of the light field that forms the Rydberg EIT. This method considerably simplifies theoretical analysis and the experimental system required for measuring microwave polarization using Rydberg atoms and is of interest in microwave sensing.
Diode Laser Systems for Photodynamic Therapy
Authors: Doiron Daniel R.
Published: February 2023

Diode lasers have long been viewed as the future technology for clinical light sources for use in Photodynamic Therapy (PDT). This has been based on their small size, high efficiency, potential reliability and potential low cost. The requirement for a laser source in PDT is based on their ability to deliver light efficiently through small single optical fibers. This in turns allows for endoscopic and interstitial use. The wavelength of the diode source must match that of the absorption of the photosensitizer used, which are chosen to provide good tissue penetration. Due to the high tissue penetration requirements wavelengths in the red and near infrared are used. At present the photosensitizers in clinical testing and commercial development have peak absorptions in the 630nm to 695nm range, while preclinical testing includes photosensitizers with absorption extending up to 800nm. Above 800nm the photophysics of the compounds tend to make them less desirable for use in PDT. The accuracy and stability of the center wavelength of the light source, and its bandwidth, must match to the action spectrum of the photosensitizer in-vivo. For example the first generation photosensitzer Photofrin® activation is specified as 630+/-3nm while for the second generation photosensitizer SnET2 it is 664+/-7nm.
Blue-Green Electron Beam Pumped Vertical-Cavity Surface-Emitting Laser Using MBE Grown Modulated ZnCdSe/ZnSe Superlattice
Authors: Basov N.G. , Dianov E.M. , Kozlovsky V.I. , Krysa A.B. , Nasibov A.S. , Popov Yu. M. , Prokhorov A.M. , Trubenko P.A. , Shcherbakov E. A.
Published: February 2023

The use of a broad-bandgap II-VI semiconductors and their ternary and quaternary alloys for vertical-cavity surface-emitting laser (VCSEL) fabrication open a new additional possibilities for their design and applications. In particular, one of the promising using is the realization of a large screen color high definition TV (HDTV) laser projection systems, and flat panel color displays [1,2]. One of the main advantages of the II-VI VCSEL's, in this case, is the possibility of the full color HDTV laser screen creation based only on this materials. The bulk II-VI compounds were used recently for the first successful demonstration of the laser cathode ray tube (LCRT) and color laser TV system [3]. However, one of the limitations of this scheme was the sufficiently high E-beam current threshold, in particular, for the room-temperature operation.
High Power Highly Efficient Vertical-Cavity Surface-Emitting Laser Diodes with a Au-Plated Heat Spreading Layer
Authors: Wipiejewski T. , Peters M. G. , Thibeault B. J. , Young D. B. , Coldren L. A.
Published: February 2023

Vertical-cavity surface-emitting lasers (VCSELs) are gaining increasing attention due to their interesting properties. The ultimate device performance of VCSELs has exceeded in-plane laser data already regarding minimum threshold currents [1] and highest wall plug efficiency except for high output power pump lasers [2]. Whereas VCSELs are poised to prove their usefulness in short distance data link applications, high efficiency lasers are also attractive for high power applications like laser diode pumped solid state lasers. In general, the maximum output power of VCSELs is thermally limited. Improved heat sinking is therefore necessary to increase the maximum output power. A record high output power of 113 mW has been previously demonstrated with an up-side down mounting of a single VCSEL on a diamond heat sink [3]. Here we show how the thermal heat sinking in a 2D laser array can be improved by using a Au-plated heat spreading layer. The improved heat sinking results in an increase in maximum output power from 20 mW to 42 mW for a 64 µm diameter device. To our knowledge this is the highest output power for an unmounted VCSEL reported to date.
Asymmetric Cladding Ridge Waveguide Laser by Selective Area MOCVD
Authors: Smith G.M. , Forbes D.V. , Lammert R.M. , Coleman J.J.
Published: February 2023

Stable fundamental mode operation of a semiconductor laser is a requirement for nearly all laser applications and the method to achieve that goal is usually an index guided laser. Two common index guided laser structures are the buried heterostructure (BH) and the ridge waveguide (RW). Both of these structures have been shown to have stable fundamental mode operation to several times threshold [1-3]. Generally, BH lasers have more stable operation but RW lasers are simpler to fabricate. RW lasers are commonly fabricated by etching trenches into the top cladding layer to within a few tenths of a micron of the active region, thus reducing the effective index of the mode in the etched region. The index step for the waveguide is a strong function of the etch depth and precise control of the etch mechanism is necessary to provide an adequate amount of waveguiding without introducing unnecessary loss by etching too deep.
Lasing characteristics of pillar-type microcavity lasers
Authors: Yoshida H. , Tezuka T. , Nunoue S.
Published: February 2023

Recently, spontaneous emission enhancement in pillar-type microcavities was reported for the first time by the authors.1) This type of cavity structure is relatively easy to fabricate and is suited to large scale integration of surface emitting laser arrays.2) It has been predicted that microcavity lasers, whose cavity size is of the order of one or a few times of the emission wavelength, have the potential for realizing ultralow thresholds (<1μA) and ultrafast modulation (>20GHz).3,4) Ultimately, low threshold lasers imply, to some extent, smaller lasers. To realize such lasers, reduction of losses of carriers and photons due to surface recombination and scattering of light in the cavity structures are very important points. In this paper we show lasing characteristics of micron size cavities up to 2.5μm in diameter. We also show experimental studies of the cavity size dependence of lasing characteristics and microscopic reflection spectra of pillar-type microcavity lasers and discuss their relation to surface recombination and optical losses due to the scattering of light on the sidewalls.
Numerical Analysis of Distortions in Directly Modulated Semiconductor Lasers in the Presence of Weak Optical Feedback
Authors: Haldar M.K. , Mendis F.V.C. , Wang J.
Published: February 2023

Subcarrier multiplexed (SCM) optical communication systems have been studied by many researchers for their attractiveness in providing simple, low-cost and broad-band optical fibre communications. In practical SCM systems, some light unintentionally fed back into the laser diode through various discontinuities such as splices adversely affect the performance of directly modulated semiconductor lasers. Many studies have been done carried out both theoretically and experimentally[1-4]. Using small signal perturbation method, Helms[2] gave expressions for modulation response, third order two carrier intermodulation distortion and second harmonic distortion which were shown to be in reasonable agreement with experimental results, especially when the modulating signals are small. Nevertheless, when modulating signals are large, small signal analysis may lose its accuracy and validity. In this paper, we use numerical methods to study the distortion produced by a directly modulated laser diode with weak coherent optical feedback.
A Correct Way to Model Arbitrary Complex Distributed FeedBack (DFB) Lasers in The Above Threshold Regime
Authors: Hsin Wei
Published: February 2023

Most of the published papers on the above-threshold simulation for DFB lasers utilize the powerful transfer matrix method (TMM) to include the longitudinal variations of the carrier and photon profiles caused by spatial hole burning and gain saturation effects at high output power[1]-[7]. However the approaches used to calculate the above-threshold behaviors were not correct. The most general mistakes are: (i). The use of the wrong threshold condition for the lasing mode both at and above threshold[2]- [5],[7] (ii). The iteration algorithm used to solve the above-threshold behavior for higher order DFB modes did not include the influence of the lasing mode properly[1],[2],[4],[5],[7].
High power diffraction-limited ultrashort pulse generation from double tapered semiconductor laser diodes
Authors: Jiang Ziping , White I.H. , Laughton F. , Penty R.V. , McCall M.W. , Tsang H.K.
Published: February 2023

One promising way of generating high power diffraction-limited output from a semiconductor laser diode is to fabricate a double tapered device by varying the stripe width along the cavity, in order to produce wide stripes at the facets and a narrow stripe at the center. The narrow stripe near the middle of the cavity acts as a spatial filter to maintain a good quality spatially coherent output, whilst the wide stripes at the facets have the dual benefits of increasing the active volume (thus increasing optical power generation) and increasing the threshold power before catastrophic facet damage occurs. High power single lateral mode operation has already been demonstrated by using various tapered devices[l, 2, 3] and much work has been carried out on tapered semiconductor laser amplifiers [5, 4]. However, the nature of double tapered device in obtaining high power and diffraction limited output is still poorly understood and optimization in design is badly needed.
Theory of Sub-Picosecond Semiconductor Lasers
Authors: Leegwater Jan A.
Published: February 2023

Theories of laser mode-locking were developed in the seventies for dye lasers. However, semiconductor lasers are characterized by quite different parameters and the approximations that can be justified for dye lasers break down for semiconductor lasers. In this paper we study the resulting pulse duration using the model introduced by New and Haus [1, 2] with both slow and fast absorbers. In the fast-and-slow-absorber model of Haus the electric field of the pulse after round-trip i is given by a
i
(t). While propagating through the cavity the pulse is modified by each of the elements of the cavity in some way.
Thermal Modeling of VCSEL-based Optoelectronic Modules
Authors: Morozova N. D. , Lee Y. C.
Published: February 2023

In recent years, many papers have been published about the thermal properties of a single vertical cavity surface emitting laser (VCSEL) and two-dimensional (2-D) arrays. However, a thermal model of VCSEL-based optoelectronic modules has needed to be developed, since the temperature distribution and heat dissipation in optoelectronic packaging affect the device's output characteristics. The device heating places upper limits on the maximum obtainable power as well as on the temperature range of operation. The development of reliable VCSEL-based optoelectronic modules strongly depends on proper thermal management.
Market Requirements on Semiconductor Lasers for Telecommunications
Authors: Olsson N.A. , Hartman R.L. , Wilt D.P.
Published: February 2023

We review the key market and technological requirements on semiconductor lasers for commercial applications in telecommunications. We will cover high volume applications for access systems as well as high-reliability and high-performance requirements.
Wavelength Uniformity in λ/4-Shifted DFB Laser Array WDM Transmitters
Authors: Young M.G. , Koch T.L. , Koren U. , Tennant D.M. , Miller B.I. , Chien M. , Feder K.
Published: February 2023

Wavelength division multiplexed (WDM) optical transmission requires laser sources with wavelengths closely aligned to the pass-bands of demultiplexing optical filters at the receiving end. A common and simple strategy to meet this demand is the use of wavelength-stabilized discrete sources and passive demultiplexing filters without active tracking, i.e., both the source and the demultiplexing filter being independently responsible for maintaining the wavelength channel assignment within a prescribed accuracy. Properly engineered distributed feedback (DFB) laser resonators are well-known in their ability to offer exceptionally robust longitudinal mode stability, both in their long-term resistance to mode jumps with environmental and operating condition changes, and in basic side-mode suppression characteristics. Temperature-stabilized DFB lasers have been shown to have very low (0.1nm-level) wavelength drift with aging over system life[1,2].
Adaptive Fraunhofer Diffraction Particle Sizing Instrument Using A Spatial Light Modulator
Authors: Dan Hirleman E. , Dellenback Paul A.
Published: February 2023

Electro-optical sensors can measure a variety of properties important in manufacturing and industrial processes such as temperature, species concentrations, particle sizes, flow velocities and rates, surface characteristics and velocities, and part geometry. The performance improvements available from next-generation electro-optical sensors will be due in part to the integration of some forms of artificial intelligence into the system. For example, we are interested in sensors which might autonomously adapt themselves to optimal or near-optimal configurations as dictated by the instantaneous measurement context. Many schemes for adaptive control of sensor systems can utilize spatial light modulator technology whereby the spatial distribution of an optical field can be controlled. We are investigating laser diffraction particle sizing systems where the angular distribution of scattered light is collected at multiple angles for use in an inverse scattering calculation. Spatial light modulators (SLM) can be used to create programmable detector geometries which can be optimized depending on the particular particle size distribution under analysis. In this paper we the discuss the integration of Faraday-effect magneto-optic spatial light modulators into adaptive laser diffraction particle sizing instruments.
Bipolar Joint Transform Image Correlator
Authors: Javidi B. , Kuo C. J. , Odeh S. F.
Published: February 2023

Recently, we have introduced a bipolar joint transform image correlator+ with substantially superior performance compared to the classical optical correlator. The bipolar image correlator uses nonlinearity at the Fourier plane to binarize the Fourier transforms’ interference intensity to only two values, 1 and -1. The performance of the bipolar optical correlator has been compared to the classical optical correlator in the areas of light efficiency, correlation peak to sidelobe ratio, autocorrelation bandwidth, and cross-correlation sensitivity. The correlation signals obtained by the conventional technique suffer from low light efficiency, large correlation sidelobes, large autocorrelation bandwidth, and low discrimination ability. It was shown that compared to the classical correlator, the bipolar joint transform correlator provides significantly higher peak intensity, larger peak to sidelobe ratio, narrower autocorrelation bandwidth, and better cross-correlation sensitivity. The bipolar joint transform correlator produces delta function-like autocorrelation signals, and much narrower and smaller zero order term on the optical axis. Since the autocorrelation functions have delta function features, larger reference images can be used and the restrictions on the locations of the images and their autocorrelation bandwidth, which exists for the classical joint Fourier transform correlator, is eliminated.
Image Correlation Using a Deformable Mirror Device as a Programmable Fourier Plane Filter
Authors: Florence James M.
Published: February 2023

The deformable mirror device (DMD) light modulator is a monolithic silicon integrated device that operates by the electro-static deflection of miniature mirror elements.1 There are a variety of different mirror element structures and array sizes currently under development for different light modulating applications. For optical image processing applications, a pixel structure capable of phase modulation is of particular interest. A phase modulator can be used in the Fourier plane of a coherent optical system to implement phase-flattening filters for image correlation or other operations where manipulation of Fourier transform phase is required.
Deformable Mirror Device Spatial Light Modulators and its Application to Neural Networks
Authors: Collins Dean R. , Sampsell Jeffrey B. , Florence James M. , Penz P. Andrew , Gately Michael T.
Published: February 2023

Neural Networks are a nontraditional method for performing computations. Neural Network architecture is a fine grain, parallel architecture with simple processors coupled at long range to the inputs. Figure 1 shows a simple picture of a layered neural network. Computation is performed by multiplying each input to every processor (node) by a weighting factor and then summing the products. The sum is then thresholded and an output is obtained from each node. The nonlinear thresholding operation provides the decision making mechanism.
Limitations of Currently Available Deformable Mirror Spatial Light Modulators
Authors: Gregory Don A. , Kirsch James C.
Published: February 2023

The Spatial Light Modulator (SLM) is perhaps the most critical element in several optical processing architectures such as the Vander Lugt Matched Filter Correlator and the Joint Transform Correlator. The SLM is a device used to encode information onto a laser beam so that it may be processed by a coherent optical system. Several devices are available which perform this critical task. The optical characteristics of these devices will determine, to a large extent, the speed, resolution, and efficiency of an optical system since the SLM is responsible for supplying the system with new information. The Hughes Liquid Crystal Light Valve (LCLV) is a reflection type SLM that is both optically addressed and read. The limitations of the LCLV are its low sensitivity to the write light, low resolution, and slow response time. The Semetex/Litton Magneto-Optic Device (MOD) is a transmission type SLM that is electrically addressed and optically read. The MOD is comparable in resolution to the LCLV but the optical throughput of the device is only 3-5%. Neither device will operate at high frame rates.
Two-Dimensional Electrically-Addressed Si/PLZT Spatial Light Modulator Arrays
Authors: Wang J. H. , Esener S. C. , Lin T. H. , Dasgupta S. , Lee S. H.
Published: February 2023

In the last few years extensive efforts have gone into the development of spatial light modulators ( SLMs) for the realization of massively parallel optical processors[1,2]. The silicon-PLZT SLM approach is one of the promising approaches and has the potential of combining the computational power of silicon and the communication power of optical interconnects. By using the third direction normal to the processing plane, the Si/PLZT approach allows the optical interconnects to provide the advantages of high speed parallel and global interconnections to simple silicon electronic circuits performing local computational operations. In this paper, we report on the successful fabrication of two-dimensional electrical matrix-addressed SLMs by integrating silicon MOSFETs and electro-optic PLZT light modulators on the same substrate (PLZT) using a simultaneous laser crystallization and diffusion technique[3]. When fully developed into large arrays this Si/PLZT electrically addressed SLM (ESLM) can be used efficiently as an input device to optical processors, transducing electrical information into optical form while being fully compatible in data format with the optically addressed Si/PLZT SLMs presently under development at UCSD. In what follows we describe the theory and design consideration for the Si/PLZT ESLM, detail the experimental techniques used and discuss the results obtained.
On the Progress of the Liquid Crystal Television Spatial Light Modulator
Authors: Liu Hua-Kuang , Chao Tien-Hsin
Published: February 2023

The pocket-sized liquid crystal televisions recently marketed by several Japanese companies have been welcome gifts among friends and found useful in applications such as the view-finders in video cameras. Many optical processing researchers have also begun to use these devices as a spatial light modulators (SLM's) in a variety of ways. It has been demonstrated that LCTV's can be used as optical input devices, logic elements, computer generated hologram recordings, and 2-D phase image representations. The LCTV may be used for these processing applications because it has several attractive features. For example, it is electronically addressable through a microcomputer, and since it is a TV by design, it is naturally addressable by a TV camera and it can be refreshed at a speed of 30 Hz. By definition, when the LCTV is used as a SLM, it can be controlled remotely by an emitting antenna anywhere in the world. So one can imagine that a joint experiment on optical processing could be performed by researchers from Asia, Europe, and the United States through the TV transmitter and receiver linkage. The speed of 30 frames/sec. is sufficient for the present usage because the inputting of image signals from a computer can hardly exceed this speed.
Dynamic Interconnections with a Lenslet Array and an SLM
Authors: Glaser I. , Sawchuk A. A.
Published: February 2023

A digital circuit can be implemented with a global linear transformation and a point non-linearity. Several suggestions, and a few experimental demonstrations, have shown that, by using optics to implement the global transformation part, hybrid opto-electronic digital processors can be built (1,2). Though such hybrid systems are still limited by the switching time of the electro-optical or electronic point-non-linear part of the system, their overall throughput can benefit from the inherent parallelism of lightwave communication, particularily when a free-space, three dimentional, optical configuration is being used; unlike conventional electronic gate-arrays, these hybrid opto-electronic ones have no “design rules” that limit the complexity and generality of their interconnections.
Real-time Object Recognition and Classification by Code Division Multiplexed Phase-only Encoded Filters
Authors: Javidi B. , Odeh S. F.
Published: February 2023

A multiobject shift invariant pattern recognition system that uses Code division multiplexed binary phase-only filters is presented. The system computes the binary correlation between an input pattern with a generalized set of pattern functions. This technique uses a filter which consists of a set of binary phase-only code division multiplexed reference pattern functions. The functions in the reference set may correspond to either different objects or different variations of the object under study. In the proposed architecture, the position of the output binary correlation peaks represent the locations of the objects in the input plane. This is different from phase coded pattern recognition systems in which the location of the output peak determines the class of the input object+. Here, the system is shift invariant and multiple objects can be present at the input plane. The pattern recognition is performed without increasing the space-bandwidth product requirements of the system. Computer simulations of the architecture are also used to study the performance of the pattern recognition architecture. The signal-to-noise ratio (SNR), and the peak to the maximum correlation sidelobe ratio (P/SL) are evaluated as the criteria for the system performance.
Active-Matrix-Addressed Viscoelastic Spatial Light Modulator
Authors: Gerhard-Multhaupt R. , Tepe R. , Brinker W. , Molzow W.-D.
Published: February 2023

Thin metallized viscoelastic layers with active-matrix addressing are proposed as spatial light modulators (SLM's) for eventual use in a reflective Schlieren light valve or in other electro-optical devices. A periodic deformation of the mirror electrode covering the viscoelastic layer leads to diffraction of the incoming light; the relative light intensities in the diffraction orders are determined by the deformation amplitude and can thus be controlled by means of the applied voltages. In order to obtain an almost linear deformation response with relatively small video signals Vs, a constant bias voltage V0 is applied between the top (mirror) electrode and the interdigital-electrode grid. Further details of the suggested viscoelastic SLM and a theoretical analysis of its deformation behavior are found in previous articles [1, 2].
Theoretical Resolution of a Thin Photoconductor Coupled Liquid Crystal Light Valve
Authors: Oh Tae-Kwan , Davis Jack H. , Ashley Paul R.
Published: February 2023

The hydrogenated amorphous silicon (a-Si:H) photoconductor and the nematic liquid crystal BDH-E44 combine to create a liquid crystal light valve (LCLV). The transmission of the readout light is determined by the voltage across the liquid crystal. When write light illuminates the current carrying photoconductor, the potential of each layer is rearranged through the photoconductor and liquid crystal.
Future Roles of Spatial Light Modulators in Advanced Computing Architectures
Authors: Neff John A.
Published: February 2023

One of the areas of computer architecture with the most rapid growth is that of parallel multiprocessors - an interconnection of anywhere from a few processing elements (PEs) to millions of PEs operating in parallel on the same problem. Attempts at solutions to many difficult problems in the past resulted in a rapid increase in complexity of software. With the continuing decline in the cost of hardware, attention has turned toward mapping such problems on massively parallel machines. For example, knowledge base searching can be done by pursuing many paths in parallel rather than following a complex algorithm that attempts to guide a serial search in an optimum fashion. The result is that many more computations are performed when following the parallel approach, with most not leading to a solution; however, the correct solution will most often be arrived at much sooner.
Effects of Sampling and Binarization on the Output of the Joint Fourier Transform Correlator
Authors: Davis Jeffrey A. , Merrill Ethan A. , Cottrell Don M. , Bunch Robert M.
Published: February 2023

The joint Fourier transform correlator (JFTC) architecture1-3 is of great interest since prior knowledge of the target is not required. However spurious peaks in the output plane have been reported from the use of binary SLMs for recording the joint power spectrum4. In this work, we analyze various causes for these kinds of anomalous results.
Self-Learning Optical Neural Network
Authors: Yu Francis T. S. , Lu Taiwei , Gregory Don A.
Published: February 2023

One of the features in neural computing must be the adaptability to changeable environment and to recognize unknown objects. In general, there are two types of learning processes that are used in the human brain; supervised and unsupervised learnings [1]. In a supervised learning process, the artificial neural network has to be taught when to learn and when to process the information. Nevertheless, if an unknown object is presented to the artificial neural network during the processing, the network may provide an error output result. On the other hand, for unsupervised learning (also called self-learning), the students are learning by themselves, in which based on simple learning rules and their past experiences. Kohonon's model is one of the simplest self-organizing algorithms[1], which is capable of performing statistical pattern recognition and classification, and it can be modified for optical neural network implementation. A compact optical neural network of 64 neurons using liquid crystal televisions is used for unsupervised learning process[2].
4×4 Fiber Optic Crossbar Switch using the Deformable Mirror Device
Authors: McDonald T. Gus , Boysel R. Mark , Sampsell Jeffrey B.
Published: February 2023

The Deformable Mirror Device (DMD) is a micromechanical spatial light modulator that offers both amplitude and/or phase modulation. It is comprised of small mirror elements suspended above silicon addressing circuitry by small hinges attached to support posts. [Ref. 1] The pixel can be made to rotate about its hinge axis by applying a potential difference between the pixel and the addressing electrode. Both area array and linear DMDs have been built and found application in several areas. [Ref. 2, 3, 4]
Color Holographic Storage in LiNbO3
Authors: Yu Francis T. S. , Wu Shudong , Mayers Andy , Rajan Sumati
Published: February 2023

Single wavelength hologram techniques have been extensively developed and applied. However, the applications of color holograms have not received much attention. Holographic film are of finite thickness, about 5-20(im, and can not have enough wavelength selectivity for color hologram recording. Some specific techniques such as rainbow hologram111, Denisyuk’s white-light reflection hologram [2], have been developed to alleviate the problem. However, rainbow holograms suffer from color blur, loss of parallax information, and reflection holograms have emulsion shinking problems which hinder faithful color reconstraction.
Metal-CdTe-lnSb Self Elecro-Optic Switching Device
Authors: Wang Chi-Luen , Ghosh P. K. , Song Q. Wang , Kornreich P. G.
Published: February 2023

We have built and tested a nonlinear etalon consisting of an epitaxial CdTe film grown on a single crystalline highly polished InSb wafer. The CdTe film was covered with a 10 nm thick aluminum film. Both the metal film and the polished InSb substrate act as mirrors. They form the optical cavity of the etalon.
Optical Response of Homeotropically Aligned Ferroelectric Liquid Crystal
Authors: Brodzeli Z. M. , Kompanets I. N. , Parfenov A. V. , Denisov A. F. , Pozhidaev E. P. , Chigrinov V. G.
Published: February 2023

A stability of homeotropically aligned C*FLC layer and the optical response 20 μs in electric field 2 4 V/μm at room temperature are advantages for fast FLC devices.
Optical Characteristics of Deformable Mirror Spatial Light Modulators
Authors: Florence James M.
Published: February 2023

Deformable mirror device (DMD) spatial light modulators are a unique family of silicon integrated circuits that combine addressing circuitry and light modulating elements in a single monolithically fabricated part. The DMD light modulators have moderately high resolution with pixel spacing of approximately 25 µm in 128 by 128 arrays. The on-chip electronic addressing circuitry is capable of full frame addressing of the 128 by 128 array at rates as high as 8000 frames per second. The details of the fabrication, electronic addressing, and the electro-mechanical aspects of these devices have been reported in several papers. [1-3] Applications of the DMD light modulators to optical correlation, frequency excisors, optical switching, folded spectrum analysis, and optical neural networks have also been reported.[4-7] This paper describes the optical modulation characteristics of DMD elements and compares the response characteristics of three different types of deformable mirror structures.
Spatial Light Modulators in Parallel Optical Memories
Authors: Psaltis Demetri
Published: February 2023

The role of Spatial light modulators in systems that use optical memories with parallel access will be assessed.
Comparison of Noise Characteristics of Some SLMs Used in Optical Computing
Authors: Batsell S.G. , Walkup J.F. , Krile T.F.
Published: February 2023

One of the principle system performance considerations in the design of an optical linear algebra processor is how to improve its computational accuracy. The fundamental limitation in achieving high accuracy is the underlying noise of the system. As active spatial light modulators(SLMs) are needed to perform multiplication for real-time operation of optical linear algebra processors, the noise properties of these SLMs are of great interest in performing system design tradeoffs to maximize accuracy. We have experimentally measured the noise properties of several SLMs that are currently being considered in OLAP architectures. We present the experimental results and, using these results, compare the devices using the signal-to-noise ratio (SNR) at the output of system.
Depolarization in Liquid Crystal TV’s
Authors: Pezzaniti J. Larry , McClain Stephen C. , Chipman Russell A. , Yau-Lu Shih
Published: February 2023

The polarization properties of a TVT-6000 liquid crystal television have been mapped as a function of bias voltage to the pixels and angle of incidence using a Mueller matrix imaging polarimeter at 632.8 nm.
Microlaser Array Spatial Light Sources
Authors: Jewell J.L. , Olbright G.R. , Bryan R.P. , Fu W.S.
Published: February 2023

The ability to generate one- and two-dimensional arrays of light beams in arbitrarily redefinable patterns addresses an enormous range of applications.
VLSI/Liquid Crystal Winner-Take-All Modulators for Optical Competitive Learning
Authors: Slagle Timothy M. , Wagner Kelvin
Published: February 2023

An optical winner-take-all (WTA) device which chooses the largest of an array of optical intensities would be useful for a variety of applications.
A Space-Modulating Ferroelectric Liquid-Crystal Light Valve and its Application to Multi-Valued Logic Gates
Authors: Kohda Shigeto , Inaba Yasushi , Yamauchi Noriyoshi , Hirai Masakatsu
Published: February 2023

Electro-optical logic gates using liquid-crystal light valves (LCLV) have been studied for a wide range of applications including digital optical computing, optical communications and optical neural networks(1)(2).
Bonding of Si thin films to PLZT Substrates for Smart Spatial Light Modulator Applications
Authors: Jin M.S. , Wang J. H. , Ozguz V. H. , Lee S. H.
Published: February 2023

In order to realize smart spatial light modulators (S-SLMs), electronic processing materials (e.g. Si, GaAs) and light modulation materials (e.g. Ferroelectric ceramics or liquid crystals, III-V semiconductors, Si) need to be combined.
Hybrid Silicon/gallium Arsenide Inverted Fabry-Perot Cavity MQW Spatial Light Modulators
Authors: Tanguay Armand R. , Madhukar Anupam , Jenkins B. Keith
Published: February 2023

High bandwidth (>10 MHz) smart pixel SLMs based on the hybrid integration of silicon based detection and control electronics with gallium-arsenide-based MQW modulators by flip chip bonding are described.
Applications and Technology of Quantum Well Self-Electrooptic-Effect Device Arrays
Authors: Miller David A. B.
Published: February 2023

Self-electrooptic-effect devices (SEEDs) [1] are combinations of quantum well modulators and photodetectors, possibly with other circuitry, that allow devices with optical inputs and outputs.
Spatial Light Modulator using Semi-Insulating Multiple Quantum Well Material
Authors: Partovi A. , Glass A. M. , Chiu T.H.
Published: February 2023

In recent years, the large excitonic electroabsorptive nonlinearities of multiple quantum wells (MQWs) has been used for electrically as well as optically addressed two dimensional optical modulators.