bluuebunny/crossref_metadata_2025 huggingface dataset:
THE “GOOD DOCTOR” PERFORMANCE OF RADIOLOGICAL ANNOTATION: MEASURING PELVIC TILT AS AN EXAMPLE
Authors: Chai Y. , Boudali A.M. , Farey J. , Walter W.L.
Published: February 2023

Human error is usually evaluated using statistical descriptions during radiographic annotation. The technological advances popularized the “non-human” landmarking techniques, such as deep learning, in which the error is presented in a confidence format that is not comparable to that of the human method. The region-based landmark definition makes an arbitrary “ground truth” point impossible. The differences in patients’ anatomies, radiograph qualities, and scales make the horizontal comparison difficult. There is a demand to quantify the manual landmarking error in a probability format.

Taking the measurement of pelvic tilt (PT) as an example, this study recruited 115 sagittal pelvic radiographs for the measurement of two PTs. We proposed a method to unify the scale of images that allows horizontal comparisons of landmarks and calculated the maximum possible error using a density vector. Traditional descriptive statistics were also applied.

All measurements showed excellent reliabilities (intraclass correlation coefficients > 0.9). Eighty-four measurements (6.09%) were qualified as wrong landmarks that failed to label the correct locations. Directional bias (systematic error) was identified due to cognitive differences between observers. By removing wrong labels and rotated pelves, the analysis quantified the error density as a “good doctor” performance and found 6.77°-11.76° maximum PT disagreement with 95% data points.

The landmarks with excellent reliability still have a chance (at least 6.09% in our case) of making wrong landmark decisions. Identifying skeletal contours is at least 24.64% more accurate than estimating landmark locations. The landmark at a clear skeletal contour is more likely to generate systematic errors. Due to landmark ambiguity, a very careful surgeon measuring PT could make a maximum 11.76° random difference in 95% of cases, serving as a “good doctor benchmark” to qualify good landmarking techniques.
DEVELOPING AND EVALUATING THE SMART CHOICE (KNEE): A PATIENT-FOCUSED TOOL TO PREDICT HEALTH-RELATED QUALITY OF LIFE OUTCOMES AFTER TOTAL KNEE ARTHROPLASTY
Authors: Zhou Y , Dowsey M , Spelman T , Choong P , Schilling C
Published: February 2023

Approximately 20% of patients feel unsatisfied 12 months after primary total knee arthroplasty (TKA). Current predictive tools for TKA focus on the clinician as the intended user rather than the patient. The aim of this study is to develop a tool that can be used by patients without clinician assistance, to predict health-related quality of life (HRQoL) outcomes 12 months after total knee arthroplasty (TKA).

All patients with primary TKAs for osteoarthritis between 2012 and 2019 at a tertiary institutional registry were analysed. The predictive outcome was improvement in Veterans-RAND 12 utility score at 12 months after surgery. Potential predictors included patient demographics, co-morbidities, and patient reported outcome scores at baseline. Logistic regression and three machine learning algorithms were used. Models were evaluated using both discrimination and calibration metrics. Predictive outcomes were categorised into deciles from 1 being the least likely to improve to 10 being the most likely to improve.

3703 eligible patients were included in the analysis. The logistic regression model performed the best in out-of-sample evaluation for both discrimination (AUC = 0.712) and calibration (gradient = 1.176, intercept = −0.116, Brier score = 0.201) metrics. Machine learning algorithms were not superior to logistic regression in any performance metric. Patients in the lowest decile (1) had a 29% probability for improvement and patients in the highest decile (10) had an 86% probability for improvement.

Logistic regression outperformed machine learning algorithms in this study. The final model performed well enough with calibration metrics to accurately predict improvement after TKA using deciles. An ongoing randomised controlled trial (ACTRN12622000072718) is evaluating the effect of this tool on patient willingness for surgery. Full results of this trial are expected to be available by April 2023.

A free-to-use online version of the tool is available at smartchoice.org.au.
Linear Consecutive-k-out-of-n: G System Reliability Analysis
Authors: Chopra Garima , Ram Mangey
Published: February 2023

The concerned study pertains to the development of a new stochastic model for the reliability analysis of linear consecutive-k-out-of-n: G system, where k>n2. In the developed model, system may collapse as a result of common cause failure or hardware failure in its units. The system has exponentially distributed failure rates, and in case of breakdown, it is repaired with the copula method. The developed model has been examined through supplementary variable technique (SVT) along with Laplace transform. The current paper has specifically studied consecutive-(n-1)-out-of-n: G system. The performance of such system having ten components is explored and its various reliability measures have been obtained and discussed with the help of graphs. The originality of this work lies in incorporating common cause failure in conjunction with copula repair in the reliability modeling of consecutive systems through the SVT. The study confirms that an increase in failure rates and the number of components of the concerned system decreases mean time to failure (MTTF). The profit of linear consecutive-9-out-of-10: G system is examined with the help of a numerical example.
SENTIR-SE VIVO NUM POEMA: SOBRE O LIVRO PÁTIO, DE JORGE REIS-SÁ
Authors: Carneiro Ramos André
Published: February 2023

A poesia de Jorge Reis-Sá, inquieta representante de uma profícua geração de novíssimos poetas portugueses, convida-nos a um passeio por um sítio ao mesmo tempo inusitado e reconhecível. Em Pátio, livro do autor publicado no Brasil pela primeira vez, o que se vislumbra é uma sedutora entrada, com portões escancarados ao desafio do rememoramento, exercício que aos leitores se expande, do mero olhar para trás a um mergulho existencial em algumas de nossas esvoaçantes raízes; o reconhecimento, ou melhor, o enfrentamento proposto por este lugar poético – de neblina, sonho, morte e memória –, torna-se tão urgente quanto um respiro.
Automatic measurement of anterior chamber angle parameters in AS-OCT images using deep learning
Authors: Yang Guangqian , Li Kaiwen , Yao Jinhan , Chang Shuimiao , He Chong , Lu Fang , Wang Xiaogang , Wang Zhao
Published: February 2023

The early assessment of angle closure is of great significance for the timely diagnosis and treatment of primary angle-closure glaucoma (PACG). Anterior segment optical coherence tomography (AS-OCT) provides a fast and non-contact way to evaluate the angle close using the iris root (IR) and scleral spur (SS) information. The objective of this study was to develop a deep learning method to automatically detect IR and SS in AS-OCT for measuring anterior chamber (AC) angle parameters including angle opening distance (AOD), trabecular iris space area (TISA), trabecular iris angle (TIA), and anterior chamber angle (ACA). 3305 AS-OCT images from 362 eyes and 203 patients were collected and analyzed. Based on the recently proposed transformer-based architecture that learns to capture long-range dependencies by leveraging the self-attention mechanism, a hybrid convolutional neural network (CNN) and transformer model to encode both local and global features was developed to automatically detect IR and SS in AS-OCT images. Experiments demonstrated that our algorithm achieved a significantly better performance than state-of-the-art methods for AS-OCT and medical image analysis with a precision of 0.941, a sensitivity of 0.914, an F1 score of 0.927, and a mean absolute error (MAE) of 37.1±25.3 µm for IR, and a precision of 0.805, a sensitivity of 0.847, an F1 score of 0.826, and an MAE of 41.4±29.4 µm for SS, and a high agreement with expert human analysts for AC angle parameter measurement. We further demonstrated the application of the proposed method to evaluate the effect of cataract surgery with IOL implantation in a PACG patient and to assess the outcome of ICL implantation in a patient with high myopia with a potential risk of developing PACG. The proposed method can accurately detect IR and SS in AS-OCT images and effectively facilitate the AC angle parameter measurement for pre- and post-operative management of PACG.
User and resource allocation in latency constrained Xhaul via reinforcement learning
Authors: Chughtai Mohsan Niaz , Noor Shabnam , Laurinavicius Ignas , Assimakopoulos Philippos , Gomes Nathan J. , Zhu Huiling , Wang Jiangzhou , Zheng Xi , Yan Qi
Published: February 2023

The Flexible Ethernet (FlexE) is envisioned for the provisioning of different services and hard slicing of the Xhaul in 5G and beyond networks. For efficient bandwidth utilization in the Xhaul, traffic prediction for slot allocation in FlexE calendars is required. Further, if coordinated multipoint (CoMP) is used, the allocation of users to remote units (RUs) with an Xhaul path of lower latency to the distributed unit/central unit will increase the achievable user bit rate. In this paper, the use of multi-agent deep reinforcement learning (DRL) for optimal slot allocations in a FlexE-enabled Xhaul, for traffic generated through CoMP, and for offloading users among different RUs is explored. In simulation results, the DRL agent can learn to predict input traffic patterns and allocate slots with the necessary granularity of 5 Gbps in the FlexE calendar. The resulting gains are expressed in terms of the reduction of mean over-allocation of slots in the FlexE calendar in comparison to the prediction obtained from an autoregressive integrated moving average (ARIMA) model. Simulations indicate that DRL outperforms ARIMA-based prediction by up to 11.6%
Double-dispersive spatio-spectral scanning for hyperspectral Earth observation
Authors: Hinderberger Peter , Grusche Sascha , Losekamm Martin J.
Published: February 2023

Most instruments for hyperspectral Earth observation rely on dispersive
image acquisition via spatial scanning. In such systems, the Earth’s
surface is scanned line by line while the satellite carrying the
instrument moves over it. The spatial and spectral resolutions of the
image acquisition are directly coupled via a slit aperture and are
thus difficult to adjust independently. Spatio-spectral scanning
systems, on the other hand, can acquire 2D, spectrally coded images
with decoupled spatial and spectral resolutions. Despite this
advantage, they have so far been given little attention in the
literature. Simple architectures using variable filters were proposed,
but come with significant caveats. As an alternative, we investigated
the use of two dispersion stages for spatio-spectral scanning. We
provide a theoretical treatment and show by basic experiments that a
double-dispersive system provides robust and flexible image
acquisition. Based on our results, we suggest a system concept for the
implementation of a demonstrator on a small satellite.
The Reduction of the Frequency Chirp of Two Section Distributed Feedback laser without Suppressing Spatial Hole Burning
Authors: Feng J. , Chen T. R. , Zhao B. , Yariv A.
Published: February 2023

The spectral linewidth of a DFB laser increases significantly when directly modulated at a high frequency , a phenomenon known as frequency chirping . Means for reducing the frequency chirp have included the use of laser with a smaller linewidth enhancement factor of the active material and methods which reduce the spatial hole burning (SHB). The second approach involves fabrication of either complex laser structures which introduce gain coupling or quarter wavelength shift three section DFB lasers. We report here on the measurement of the frequency chirp of a two section DFB laser under large signal modulation . It was found that the frequency chirp of a two section laser can be minimized by simply adjusting the injection current distribution in the laser. The unique advantage for using two section DFB lasers is that frequency chirp can be reduced even when SHB is not suppressed.
High power lasers for medical and graphic arts printing applications
Authors: Stutius W. , Heath L.
Published: February 2023

Ecological concerns and time and cost saving measures have started a trend towards dry-processed, high quality image recording media for digital medical and graphic arts imaging applications. As compared to silver-halide film based systems, the photosensitive layers in most of these media are considerably less sensitive than traditional wet-processed film and therefore require a high laser power for exposure. In addition, advanced screening methods, like FM or stochastic screening, require an extremely well controlled laser spot size. The most recent developments in the graphic arts industry are directed towards eliminating film as an intermediate step for plate-making altogether and instead writing the image (comprising text, line art and pictures) directly onto plates. What these technological developments have in common is that, independent of the specific method for implementation, they all rely on various high power laser sources with extremely well controlled beam properties for writing the image. This talk will address the present status of laser requirements for non-silver-halide-based medical and graphic arts printing, as well as impending industry-wide technological changes and the resulting “wish list” for advanced laser sources.
Use of vertical cavity surface emitting lasers(VCSELs) for spectroscopic applications
Authors: Bhadri Narasimha P.R. , Gupta S. , Jain R.K. , Brinkmann D.A. , Fu W.S. , Swirhun S.E.
Published: February 2023

We describe the first report of the use of VCSELs for spectroscopic applications. Using a 760 nm VCSEL tuned to one of the weak A band transitions of oxygen, a minimum detectivity of 1600 ppm was obtained, in these preliminary experiments.
Simultaneous Demultiplexing and Wavelength Conversion of NRZ Optical Signals using a Side-Injection-Light-Controlled Bistable Laser Diode
Authors: Kurokawa Takashi , Nonaka Koji
Published: February 2023

Photonic digital switches will be indispensable in future all-optical nodes for both time- and wavelength-division processing of optical signals for digital regeneration, Mux/Demux, and wavelength conversion. A bistable laser diode has the potential to achieve time- and wavelengh-divison processing simultaneously because it is inherently capable of digital regeneration due to its memory characteristics and of wavelength conversion when a side-injection structure is used [1,2]. This paper reports optical demultiplexing of 1 Gbps NRZ signals with simultaneous wavelengh conversion using a side-injection-light-controlled bistable laser diode (SILC-BLD) module with pigtailed fibers and a monitoring pin-photodiode.
Semiconductor Laser-Based Ranging Instrument for Earth Gravity Measurements
Authors: Abshire James B. , Millar Pamela S. , Sun Xiaoli
Published: February 2023

A laser ranging instrument is being developed to measure the spatial
variations in the Earth's gravity field. It will range in space to a
cube corner on a passive co-orbiting sub-satellite with a velocity
accuracy of 20 to 50 um/sec by using AlGaAs lasers intensity modulated
at 2 GHz.
Efficiency and Spectral Properties of Integrated Optoelectronic Laser-Diode-Based RF Frequency Mixers
Authors: Avrutin E.A. , Thayne I.G. , Barrow D.A. , Marsh J.H. , Portnoi E.L. , Gorfinkel V.B.
Published: February 2023

Frequency up/down conversion of optically transmitted RF signals may be useful for a number of microwave-over-fibre applications. In the earlier works [1-2], we have proposed to perform such conversion by means of operating passively Q-switched (self-pulsing) or passively mode locked semiconductor laser diodes (LDs) as integrated optoelectronic frequency mixers, i.e. as a local oscillator and a mixing element integrated within one device. Theoretical calculation proved the feasibility of RF frequency conversion due to parametric effects in such LDs. The calculations considered the input signal applied to a laser as either an electrical signal (optoelectronic scheme) or an RF modulated optical signal (all-optical scheme), the frequency-converted output being in the form of a modulated stream of optical pulses, convenient for further transmission, with an electrical signal as a by-product. In [3], optoelectronic up-conversion has been performed using self-pulsating lasers with subcarrier modulation in optical communications in view. The results of both [1-2] and [3] experimentally demonstrate the feasibility of frequency mixing in GHz range using self-pulsing lasers, but little study has been performed so far of the mixing efficiency, and the spectral properties of the device have been only studied theoretically [2] for the case of mode locked extended-cavity lasers. Here, we investigate, in more detail, the issue of the efficiency of the optoelectronic frequency conversion in dependency of frequency (in different frequency ranges) and intensity of the modulation signal for monolithic cavity Q-switched and mode locked lasers.
Influence of small radiation doses on the parameters of injection lasers
Authors: Khaydarov A. V. , Koifman A. I. , Mart’yanova I. V.
Published: February 2023

The effects of small doses (~ 103 - 104 rad) have not been studied sufficiently thoroughly, although these effects are of interest both from the point of view of the possibility of identification of the micromechanisms of radiation-defect formation and deliberate changes in the parameters of the structures, i.e., from the point of view of radiation technology.
A bi-directional transceiver PIC for Ping-Pong local loop configurations operating at 1.3 μm wavelength
Authors: Ben-Michael R. , Koren U. , Miller B.I. , Young M.G. , Koch T.L. , Chien M. , Capik R.J. , Raybon G. , Dreyer K.
Published: February 2023

For deployment of a single mode fiber to the home, one wishes to develop an inexpensive optical data link. In order to reduce the cost of a such a local loop communication system operating at 1.3 μm wavelength, the preferred mode of operation of transmitters and receivers operation in such a configuration is uncooled operation. To further reduce the cost, the transmitters would be Fabry-Perot cavity lasers, with a relatively broad spectral range of ±10 nm around the desired 1.3 μm lasing wavelength. The combination of uncooled operation and broad temperature range requires the receiver in such a configuration to have broad spectral responsivity of ±35 nm around the lasing wavelength. This is calculated taking into account the worst case scenario in temperature changes, and a ~6 Å/°C wavelength change by temperature.
InGaAs/GaAs and GaAs/AlGaAs Multiple-Quantum-Well Spatial Light Modulators
Authors: Aull Brian F. , Nichols Kirby B. , Goodhue William D. , Burke Barry E.
Published: February 2023

The need for spatial light modulators (SLMs) with high-speed electrical addressing capability motivates the development of SLM devices based on GaAs and related ternary alloys. These materials are amenable to the growth of superlattices with good optical modulation properties and to the fabrication of high-speed addressing circuitry on the same wafer.
Resolution Limits of an Imaging System with Incompressible Deformable Spatial Light Modulators
Authors: Kuhlcw B. , Mahler G. , Tepe R.
Published: February 2023

The spatial light modulator (SIM) considered here consists of a thin incompressible viscous fluid layer and is addressed by an electron beam. As a consequence of the deposited charge image, the fluid surface is deformed by electrostatic stresses. For the incident light, this surface deformation represents a phase object causing phase modulation and thus diffraction. The conversion of this (invisible) phase modulation into a (visible) intensity modulation is achieved by means of a schlieren-optical imaging system. In previous publications [1,2], the transfer characteristics of the system for sinusoidal charge patterns, which lead to sinusoidal deformations because of the control-layer's linear transfer function, were extensively described; here, the transfer characteristics of the same system for spatially non-periodic structures are analyzed, and the resolution limits caused by the incompressibility of the SIM material and by the optical filtering are determined.
High Performance TIR Spatial Light Modulator
Authors: Sprague Robert A. , Turner William D. , Bernstein Mark S. , Steinmetz David L. , Hecht David L. , Fisli Tibor , Kaminski Joseph W. , Rauch Russell B.
Published: February 2023

The TIR linear spatial light modulator, which has been discussed in a number of previous publications,1-4 is a VLSI-driven device which utilizes phase change in lithium niobate to achieve modulation of a line of light at a number of positions along a line. It does this by coupling fringing fields from a set of electrodes on a VLSI chip into the crystal and interacting with these fringing fields in a total internal reflection mode of illumination. The device is used to phase modulate the light and can be either directly read out or used in a Schlieren readout system to create intensity modulation. In this paper we present information on design, fabrication, and performance of a new high performance device which has 4735 elements and operates with a 256 MPixel/second data rate.
Evolutionary Development of Advanced Liquid Crystal Spatial Light Modulators
Authors: Collings N. , Crossland W. A. , Vass D. G.
Published: February 2023

One of the future goals for computing will be the ability to transform data arrays at high speed. Where the transformation is regular across the array, such as symbolic substitution, or can be realized with simple optical components, such as the Fourier transform, then it is a natural solution to spatially multiplex the data across a coherent light beam. This entails the need for developing SLM’s of high space-bandwidth product. In order to reduce thermal dissipation an ideal electro-optic effect should operate at low applied voltages and use a material of low dielectric constant. Liquid crystal devices fulfil some of these requirements. Here we describe the properties of multiplexed ferroelectric liquid crystal (FLC) spatial light modulators that run at faster than video frame rates. We suggest that for reasons of addressing speed, compactness, and integrability with silicon circuitry, then silicon active backplane FLC SLMs offer significant advantages. The design and potential performance of such devices is briefly discussed, as is the possible impact of a more recent fast, analogue electro-optic effect in chiral smectic liquid crystals.
Development of a spatial light modulator - a randomly addressed liquid-crystal-over-nMOS array.
Authors: McKnight D.J. , Vass D.G. , Sillitto R.M.
Published: February 2023

Following the successful fabrication of a prototype liquid crystal over silicon spatial light modulator 1,2), a more advanced version having a larger number of pixels with smaller dimensions is being developed. To provide an indication of the progress being made towards the realisation of higher performance devices, details relating to the prototype are included in parentheses in the description of the new active silicon backplane. As described below the prototype has also been used as a test-bed for optimising the performance of the light modulating layer for the new device.
An Optical Intensity and Polarization Coded Ternary Number System
Authors: Lin Shing-Hong
Published: February 2023

The lack of practical multiple-valued logic devices has in the past discouraged extensive investigation into multiple-valued logic. Recently, however, a number of optical processors have been presented to perform either multiple-valued logic functions[1,2], modified signed-digit arithmetic[3], or residue arithmetic[4]. Most of these implementations utilize position coding for the representation of residue numbers or multiple-valued numbers. For example, 9 pixels are needed to represent the combinations of two ternary inputs, and only one of the pixels will be turned ON at a time. As a result, the spatial utilization of input SLM (spatial light modulator) plane is quite low. In this paper, a new ternary number representation, which make use of both intensity and polarization codings, is proposed to perform both ternary logic operations and modified signed-digit arithmetic. The advantages of this system are that only one pixel is used to carry 1-bit information, and the conventional optical logic array[5] and SLMs, which are designed for binary system implementation, can be used in the proposed ternary system.
Transfer characteristics of Microchannel Spatial Light Modulator
Authors: Suzuki Y. , Hara T. , Wu M. H.
Published: February 2023

Microchannel Spatial Light Modulator (MSLM)1),2),3) can be used as a key device in the system for optical computing and optical neural network because this device has many functions4),5),6). The MSLM is an optical ad dressing spatial light modulator, that is, the read-out light intensity is modulated by the writing light energy. Therefore it is important to recognize its input-output characteristics (the transfer characteristics) when we design the optical system with this device. In this paper the transfer characteristics of the MSLM will be theoretically and experimentally discussed.
Recent Advances and Applications of Ferroelectric Liquid Crystal Spatial Light Modulators
Authors: Johnson Kristina M. , Handschy Mark A. , Moddel Garret
Published: February 2023

Optical computing systems offer increased information processing throughput rates by taking advantage of parallel optical architectures. The fundamental component in these architectures is a device which can modulate two-dimensional optical data. These devices, known as spatial light modulators (SLMs) have many applications including input/output data displays, spatial and matched filtering, incoherent- coherent light converters, optical crossbar switches, optical interconnection networks, and neurocomputing. The ideal system requirements placed on SLMs include high resolution (100 lp/mm), 1000 x 1000 pixels, megahertz frame rate, 100 grey levels, 1000:1 contrast ratio, and low cost [1]. An operating characteristic which often prevents SLM's from reaching these goals is device power dissipation [2]. Furthermore, devices which have large commercial markets have a better chance of meeting these systems requirements. In this paper we will discuss a new class of materials, ferroelectric liquid crystals (FLCs), that potentially can meet all the above system requirements.
Fundamental and Technological Limitations of Asymmetric Cavity MQW InGaAs/GaAs Spatial Light Modulators
Authors: Kyriakakis C. , Karim Z. , Rilum J. H. , Jung J. J. , Tanguay A. R. , Madhukar A.
Published: February 2023

Numerous applications have been envisioned for spatial light modulators in optical information processing and computing systems. The principal functional roles of both one- and two-dimensional spatial light modulators include those of format, input, output, CPU, and memory devices. Such a wide variety of applications has of course led to an equally wide variety of interrelated, and at times conflicting, device requirements that arise from fundamental physical limitations as well as current technological drawbacks. In this investigation we have examined these requirements for a particular class of modulators, the operation of which is based on an asymmetric Fabry-Perot etalon with a multiple quantum well (MQW) structure as the cavity medium.
Quantum-well Optoelectronic Switching Devices for Optical Information Processing
Authors: Aull B. F. , Nichols K. B. , Mehanian C.
Published: February 2023

One of the challenges in developing practical optical information processing systems is the development of optical switching devices that dissipate minimal energy per operation and have good optical terminal characteristics for the intended application. One can find "all-optical" devices that require low switching energy but they lack large-signal gain and must therefore be operated with critical optical biases in a narrow region of differential gain. Optoelectronic devices, on the other hand, display large-signal optical gain but their-switching energies are at least as high as the best electronic circuits. Both the optoelectronic and the "all-optical" devices perform the functions of detection, logic, and modulation using electronic effects. These three functions, however, are physically separated in the optoelectronic devices.
Two-Dimensionnal Multiquantum Well Spatial Light Modulators for Interconnexions and Optical Processing
Authors: Schnell J. Ph. , Raffy J. , Pocholle J. P. , Delboulbe A. , Dutrey G. , Lehoux J. , Werner M. , Papuchon M. , Huignard J. P.
Published: February 2023

Since the evidencing, in 1982(1), of the electroabsorption properties of semiconductor multiquantum wells, numerous researches were conducted on materials, physics(2) and demonstrators devices(3). The very short response time (limit < 1 ps) was revealed since the beginning. The relatively moderate contrasts (typically 2 : 1) of the first studies, were recently improved to 100 : 1(4) by the combination of MQW's and Fabry-Perot effects.
Spatial light modulators for photonic switching
Authors: Goodman J. W. , Dias A. R. , Chau K. K. , Kalman R. J. , Sawchuk A. A.
Published: February 2023

The requirements for spatial light modulators to be used in photonic switching systems are described. Experimental switches based on PLZT, NCAP liquid crystals, and arrays of semiconductor laser amplifiers are described.
Progress in silicon VLSI/ferroelectric-liquid-crystal micropower optoelectronic computing devices
Authors: Handschy Mark A. , Drabik Timothy J.
Published: February 2023

We report our progress in developing electrically and optically addressed silcon/ferroelectric-liquid-crystal spatial light modulators and optoelectronic computing devices.
Smart Spatial Light Modulators (SLMs) on Si/PLZT
Authors: Ersen Ali , Ozguz Volkan , Fan Chi , Esener Sadik , Lee Sing 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 [1-3]. The silicon-PLZT SLM approach is a promising approach and has the potential of combining the computational power of silicon with the communication capacity of optical interconnects [4]. Optical interconnects utilize the third dimension normal to the processing plane to provide the advantages of high speed parallel and global interconnections among simple silicon electronic circuits performing local computational operations. Fig. 1 shows the schematics of Si/PLZT SLM. In order to take more advantage of the computational power of silicon we want to increase the number of transistors we can put in each unit cell. Several logic gates combined with some storage capability and photodetectors will find many useful applications in opto-electronic systems. In this paper we discuss the improved fabrication techniques to achieve better yield and higher unit cell complexity. We will also report on the results of fabricated unit cell arrays with various complexities.
Self-Routing Algorithm for the Circularly Multistage Optical Interconnection Network
Authors: Ito Hiroyasu , Yamamoto Tsuyoshi , Nakagami Takakiyo
Published: February 2023

Due to many limitations of the electrical interconnection, optical free-space interconnection is expected to overcome its bottleneck because of the high- bandwidth , high-speed transmission, parallel multi-beam inputs, and the absence of interference among beams. Some of such attempt are found in [1],[2],[3].
The Phase Retrieval Method Using Optoelectronic Fourier Processor
Authors: Dmitriyev Nickolay I.
Published: February 2023

Recent increasing interest to the phase problem is due to adaptive optic systems design and research in the field of transparent objects computer tomography.The restriction,imposed on the phase of analysed field E(x,y)= = | K(x,y) | exp [i<£(x,y)] in the phase contrast devices, is widely known:<£(x,y) must be small,so that <£(x,y)« re .As for the iterative procedures of Gershberg -Saxton1 and Soathwell,2 phase distribution retrieval according to autocor- lation function 9 etc, ’s these algorithms are likely to be considered as a proof of existence of the phase problem solution rather then a methods which can be readily used in practice.
Thin ferroelectric Lead Lanthanum Zirconate Titanate (PLZT) films for Spatial Light Modulators on Silicon on Sapphire
Authors: Krishnakumar S. , Esener S.C. , Fan C. , Ozguz V.H. , Lee S.H.
Published: February 2023

This paper explores the development of a Silicon/PLZT on Sapphire Spatial Light Modulator using R-F magnetron sputtered thin film PLZT. Lead Lanthanum Zirconate Titanate (PLZT) is a transparent ferroelectric material exhibiting large quadratic electro-optic effect [1]. Sapphire forms an excellent choice as substrate to build high density Silicon-on-Sapphire CMOS circuits. By growing PLZT films on sapphire one can create Silicon-based Smart Spatial Light Modulators (S-SLMs). Fig.1 shows the configuration of such a device. The thin film PLZT transverse light modulators offer attractive features such as high speeds (due to low intrinsic capacitance) and low switching energies when used in a Fabry-Perot interferometer. In addition, since silicon device development is done prior to the deposition of PLZT films, CMOS VLSI circuits of any complexity can be achieved on the sapphire substrate in standard CMOS foundries. The most important step in the creation of such a device, is the growth of PLZT films of the right composition and crystallinity. In this paper we report the characterization of PLZT(9/65/35) films deposited on R plane
(11¯02) sapphire. PLZT (9/65/35) composition was chosen for its large quadratic electro-optic coefficient. R-plane
(11¯02) sapphire was chosen as substrate to provide compatibility with Silicon-on Sapphire technology.
Single Crystal Silicon Liquid Crystal Light Valve with one Millisecond Response Time
Authors: Sayyah K. , Efron U. , Wu C. S. , Wu S. T.
Published: February 2023

There is a growing need for higher frame rate spatial light modulators (SLM) for optical data processing (ODP), adaptive optics (AO), and display applications. Liquid crystal light valves (LCLV) based on nematic materials are relatively slow in their response time and typically cannot be operated beyond video rates (30-60 Hz). While the recent introduction of SLMs based on ferroelectric liquid crystals has alleviated the response time problem considerably, these devices are inherently binary and also not easily amenable to phase modulation. Other potential spatial light modulators suffer either from the limitation of binary operation like the magnetooptic SLM, or from a limited resolution like the deformable mirror SLM. Thus, there is presently no satisfactory solution to the critical needs in the fields of optical data processing and adaptive optics for continuous phase modulation at high resolution and frame rates.
Liquid Crystal IR (λ = 2-6 μm) Image Converter Based on CdSe(Ag)
Authors: Berezina G.I. , Dovgaleva N.A. , Kompanets I.N. , Parfenov A.V. , Pirkulov I.V. , Popov Yu. M. , Prokopov N.A. , Vasilishcheva I.V.
Published: February 2023

Photoelectric parameters and spatial-temporal light modulation characteristics of a structure based on CdSe(Ag) and nematic liquid crystal, sensitive in the region of λ = =2-6 μm, are considered.
Fabrication and Switching Sensitivity of the New Magneto Optic Spatial Light Modulator
Authors: Ross William E. , Lambeth David N.
Published: February 2023

A new reflected mode magneto-optic spatial light modulator (R-MOSLM) has been developed for production of Miniature Ruggedized Optical Correlators.
Multipurpose Spatial Light Modulator
Authors: Handschy Mark A. , Banas David B. , Gaalema Stephen D.
Published: February 2023

Spatial light modulators (SLMs) with sophisticated pixel functions promise to enhance the performance of optical processing systems.
Optical Data Self-Routing System Based on Multiple Quantum Well Modulator and Optical Bistable Matrices
Authors: Chavel P. , Koppa P. , Taboury J. , Oudar J-L. , Kuszelewicz R. , Schnell J-P. , Raffy J. , Pocholle J-P. , Papuchon M.
Published: February 2023

This work, currently in progress, is motivated by a general need to develop systems for optical information processing.
Computer Generated Hologram Reconstruction using Liquid Crystal Spatial Light Modulators
Authors: Sonehara Tomio , Amako Jun , Miura Hirotsuna
Published: February 2023

Liquid Crystal Devices (LCDs) have been widely used for Spatial Light modulators (SLMs) because of its easy operating characteristics.
Issues in Improving the Performance of Liquid-Crystal-over-Silicon Spatial Light Modulators
Authors: Underwood I. , Vass D.G. , O’Hara A. , Burns D.C.
Published: February 2023

The marriage of the two technologies of Very Large Scale Integrated (VLSI) silicon backplane active drive and Ferroelectric Liquid Crystal (FLC) light modulating layers has attracted much attention as a promising means of implementing compact high performance, smart and advanced Spatial Light Modulators (SLMs)[1].
Title to be announced
Authors: Fan J.
Published: February 2023

Summary not available at time of printing.
Electroabsorptive Asymmetric Fabry-Perot Modulators with Symmetric Coupled Quantum Wells
Authors: Gerber D. S. , Droopad R. , Maracas G. N.
Published: February 2023

The electroabsorptive asymmetric Fabry-Perot (ASFP) optical modulator has recently received attention for its use in electrically-addressable spatial light intensity modulator arrays due to its potentially high contrast ratio, large reflectance difference and low drive voltage1.
Self Assembly SLM for Molecular Computing
Authors: Szu Harold , Tate Ann , Cullin David , Walch Marianne , Demske David , Garcia Joseph , Phuvan Sonlinh , Caviris Nicholas
Published: February 2023

Spatial Light Modulator (SLM) useful Molecular Computing is made on a bacteriorhodopsin (BR) molecule film suspended in a viscous liquid medium, similar to a wet photograph but having adaptive and finer pixels.

The natural synergism between the thermal diffusion of BR molecule (induced externally by a write-laser) and its photochromism (generated internally by electronic transitions) is demonstrated in an edge-enhanced laser-image application.
Design of an optically addressed spatial light modulator sensitive to 1.55-μm write light
Authors: Wang Li , Moddel Garret , Burdge Geoff
Published: February 2023

Most optically addressed spatial light modulators (OASLMs) utilize photosensors of hydrogenated amorphous silicon (a-Si:H), Si, GaAs, CdS, CdSe or other photosensors which are sensitive from visible to near IR wavelengths (< 1.1 µm). Some applications such as correction of atmospheric turbulence in the eye-safe region of the spectrum for free-space optical communication demand OASLMs that have high sensitivity at 1.55 µm, high frame rate (> 1 kHz), and high resolution (MTF = 50% at 40 lp/mm). Ferroelectric liquid crystal (FLC) has very fast response and FLC OASLMs can be operated at frame rates of a few kHz[l]. An IR-OASLM with an In0.53Ga0.47As-InP photosensor and an FLC light modulating layer is being developed in our laboratories. The design, preliminary experimental results, and practical issues for such an IR-OASLM will be presented and discussed.
Ferroelectric liquid crystal spatial light modulators and their applications to information processing
Authors: Fukushima Seiji , Kurokawa Takashi
Published: February 2023

There has been increasing interest in optical processing because it is two-dimensional and massively parallel. One of the most important devices for optical parallel processing is the optically-addressed spatial light modulator. Providing logic and memory functions, it would be used to implement flexible processing. We have developed a ferroelectric liquid crystal spatial light modulator (FLC-SLM) with these kinds of functions and fast response.1 This paper describes the device and some of its uses in information processing.
Optical Image Processing Features of Optically Addressed Liquid Crystal Light Modulators
Authors: Parfenov Alexander V.
Published: February 2023

Spatial light modulators (SLM) are considered as the main elements of optical data processing systems. Liquid crystal SLMs (LC SLM) have high performance parameters, and are normally used in optical systems as image transducers and optical filters. Whereas LC SLMs are able to increase the list of their applications due some image processing features. These features are appeared when SLM internal structure properly taken into account during SLM construction. Combination of these features with high performance SLM parameters could improve a flexibility and productivity of optical methods and is able to simplify optical setup.
Spatial Light Modulators: Russian Research, Development and Applications
Authors: Kompanets Igor N.
Published: February 2023

New ferroelectric liquid crystals promising for the SLMs were created and investigated at P.N. Lebedev Physics Institute. Helical winding and shevrons were excluded all over the crystal volume, and low-energy molecular structures were recognized. Three types of FLC cells distinguished with the LC composition, layer thickness and boundary conditions were used for the light shutters and SLMs.
Responses of a Spatial Light Modulator to Pulsed Electron Irradiations
Authors: Taylor E. W. , Sanchez A. D. , Chapman S. P. , De Walt S. A. , Craig D. M. , Kelly M. A. , Mitcham M. F.
Published: February 2023

The application of photonic technologies in space and enhanced environments has progressed steadily. The first survivable fiber optic point to point links were demonstrated in 19841, paving the way for other proposed experiments including acousto-optic devices2. Radiation hardness studies of integrated3 and coupled wave optic4 devices have been performed. Photonic hardness standards are progressing from the studies of international round robin teams5,6. However, limited data exists on the radiation responses of organic spatial light modulators7 (SLMs) or acousto-optic modulators in radiation environments. This paper partially addresses this issue by examining the radiation response of a SLM.
Opto-electronic Hybrid System for Rapid Prototyping of Paraxial Diffractive Elements
Authors: Aagedal Harald , Beth Thomas , Reichel Frank , Schwarzer Heiko , Teiwes Stephan
Published: February 2023

Progress in developing and applying a young technology like diffractive optics for scientific or industrial purposes can be better supported by closely linking theory and practice. It is very helpful to validate theoretical reflections quickly by computer simulations and optical tests. However, to our knowledge, there does not yet exist a software system offering enough flexibility and comfortable handling to do extensive simulation experiments in diffractive optics. Such a system would help to concentrate on solving a given problem like the design of a diffractive element (DE) with a specific function.
Speckle-free Signal Reconstruction with Non-periodic Diffractive Elements on Liquid-crystal SLM
Authors: Teiwes Stephan , Schwarzer Heiko , Aagedal Harald , Schmid Michael , Beth Thomas , Reichel Frank , Wyrowski Frank
Published: February 2023

The methods to generate intensity signals using diffractive elements bear importance for optical signal processing and printing applications. In principle, the diffractive element (DE) can be viewed as optical memory carrying encoded information about a signal wave s(x), x ∈ ℝ2, which can be generated in a certain output plane by illuminating the DE with a specified wavefront. The capability to generate a certain signal wave, defined in a signal window, is called the optical function of a DE. On one hand, a DE can be implemented as a passive optical component with a fixed optical function. Modern spatial light modulator (SLM) technology on the other hand allows adaptive implementations, where a computer addresses the optical device. The advantage is that the optical function of the DE can be changed with time. For this reason SLMs have a key role in the design of programmable opto-electronic devices for signal generation and processing.
Diffraction Properties of Ferroelectric Liquid Crystal Optically-Addressed Spatial Light Modulators
Authors: Barbier Pierre R.
Published: February 2023

Ferroelectric liquid crystal (FLC) optically addressed spatial light modulators (OASLMs) exhibit high spatial resolution (≈50-100 lp/mm) and short switching times (≈100 μs) [1]. These devices can be used to produce dynamic holograms in optical computing [2] or phase conjugation applications [3]. To use FLC OASLMs in the diffractive mode it is important to understand their diffraction characteristics. In this paper we present OASLM diffraction efficiency measurements and analyze the switching behavior of the diffracted light as a function of the FLC grating characteristics. We then compare the experimental results with the results of the analysis and discuss the device limitations which affect the diffraction efficiency.
Fundamental Constraints on SLMs Supporting N x N Fan-in/Fan-out
Authors: Caulfield H. John , Schamschula Marius P. , Zhang Leo
Published: February 2023

The recent trend to use small SLMs (spatial light modulators) together with low f/numbers has stretched the capabilities of most SLMs1. For common SLMs, such as those based on ferroelectric liquid-crystals or the electro-optic effect, possess a small field of view, usually no more than a 5° half-angle. Low f/numbers such as those approaching 1, with half-angles up to 45° greatly exceed the capabilities of such SLMs.
Device-Architecture Interaction in Optical Computing
Authors: Athale Ravindra A.
Published: February 2023

Device technologies and processor architectures exert a strong influence on each other in optical computing. I will discuss examples of successful and unsuccessful interactions between these two communities. The role of the CO-OP in enhancing this interaction will be outlined.
Acoustic Signal Processing with Photorefractive Optical Circuits
Authors: Montemezzani Germano , Donley Elizabeth , Anderson Dana Z.
Published: February 2023

Acoustic processing of audio and sonar by animals involves the temporal as well as spatial aspects of an incoming signal. We can presume that a bat, for example, acquires an entire spatial picture of its surroundings from its sonar returns rather than some empty series of blips that the untrained human ear derives from the sound of a ship’s sonar; in effect the bat sees with its ears [1]. The barn owl makes equally impressive use of hearing with passive sonar to locate and capture prey in the dark. In these cases, and in speech recognition by humans, the sequential nature of the information plays an essential role.
Airborne Visible and Infrared Spectrometer
Authors: Vane G.
Published: February 2023

Summary not available.
Theoretical Basis and Significance of Polarization in Remote Sensing
Authors: Egan Walter G. , Whitehead Victor S.
Published: February 2023

In the visible range, sunlight that is scattered from planetary and terrestrial surfaces becomes polarized. The amount of polarization and the plane of polarization is a function of the incident and scattered radiation directions, the scattering surface structure and its optical complex index of refraction. The wavelength dependence of polarization is implicit in the aforementioned parameters. When one speaks of polarization, one refers to plane polarization, which is the dominant form in nature. Circular and elliptical polarization also occurs, but is more difficult to detect: it results from scattering/reflection from high imaginary index (high absorption) materials, which produce a significant phase change in the quadrature component of scattered radiation.