SLM Research Papers - Academia.edu (original) (raw)

There are numerous utilization of SLM steel materials, contingent upon the properties, for example, quality, malleability, and bio-compatibility. As the current SLM measure is costly contrasted with most regular manufacturing techniques, proposed applications are in high worth included businesses, for example, medication. The remarkable capacity of SLM to deliver metallic parts with complex calculations straightforwardly likewise permits analysts to investigate applications where conformal cooling channels are needed for tooling and lightweight structures for the aviation and car ventures. SLM includes the warming and liquefying of powder material with laser pillar and fast cementing of the softened material to shape the ideal segment. There are a few physical marvels that are essential to the cycle, for example, the absorptive of the powder material to laser illumination, the balling wonders that disturb the arrangement of constant melts, and the warm variance experienced by the material during the cycle that can prompt break development and part disappointment. In this segment, examinations on these parts of SLM are introduced to reveal insight into the material science engaged with the SLM cycle.

- by
- •
- Materials Science, Materials, SLM, Selective Laser Sintering

Using of welding technologies to produce metal volume objects allows considerable lowering of their manufacturing cost at simultaneous increase in productivity, compared to SLSand SLM-processes. The most perspective welding technology of additive manufacturing of threedimensional objects is plasma-arc technology with application of wires or powders. It allows creating at comparatively low heat input quality volumetric products with wall thickness from 3 to 50 mm from alloys based on Fe, Ni, Co, Cu, Ti, Al, as well as composite materials, containing refractory components.

- by Vlad Khaskin and +1
- •
- Mechanical Engineering, Robotics, Welding Engineering, 3D printing

The powder bed fusion additive manufacturing process enables fabrication of metal parts with complex geometry and elaborate internal features, the simplification of the assembly process, and the reduction of development time; however, its tremendous potential for widespread application in industry is hampered by the lack of consistent quality. This limits its ability as a viable manufacturing process particularly in the aerospace and medical industries where high quality and repeatability are critical. A variety of defects, which may be initiated during powder bed fusion additive manufacturing, compromise the repeatability, precision, and resulting mechanical properties of the final part. One approach that has been more recently proposed to try to control the process by detecting, avoiding, and/or eliminating defects is online monitoring. In order to support the design and implementation of effective monitoring and control strategies, this paper identifies, analyzes, and classifies the common defects and their contributing parameters reported in the literature, and defines the relationship between the two. Next, both defects and contributing parameters are categorized under an umbrella of manufacturing features for monitoring and control purposes. The quintuple set of manufacturing features presented here is meant to be employed for online monitoring and control in order to ultimately achieve a defect-free part. This categorization is established based on three criteria: (1) covering all the defects generated during the process, (2) including the essential contributing parameters for the majority of defects, and (3) the defects need to be detectable by existing monitoring approaches as well as controllable through standard process parameters. Finally, the monitoring of signatures instead of actual defects is presented as an alternative approach to controlling the process " indirectly."

- by Ehsan Malekipour
- •
- Additive Manufacturing, Direct Metal Laser Sintering, SLM, Online Monitoring

Phase-only holographic projection has prompted
a great deal of research and has often been cited as a desirable
method of 2-D image formation, since such a technique offers
a number of advantages over conventional imaging projection
technology [1], [2]. Although holographic image formation was
demonstrated some forty years ago [3], efforts at realizing a
real-time 2-D video projection system based on this technique
have not been successful, principally due to the computational
complexity of calculating diffraction patterns in real time and
the poor quality of the resultant images. In this paper, a new
approach to hologram generation and display is presented which
overcomes both of these problems, enabling—for the first time—a high-quality real-time holographic projector.

- by Edward Buckley
- •
- Digital Holography, Laser, Optical Communication, LCOS

An OFDM system is combined with multiple-input multiple-output (MIMO) in order to increase the diversity gain and system capacity over the time variant frequency-selective channels. However, a major drawback of MIMO-OFDM system is that the transmitted signals on different antennas might exhibit high peak-to-average power ratio (PAPR).In this paper, we present a PAPR analysis reduction of space-time-block-coded (STBC) MIMO-OFDM system for 4G wireless networks. Several techniques have been used to reduce the PAPR of the (STBC) MIMOOFDM system: clipping and filtering, partial transmit sequence (PTS) and selected mapping (SLM). Simulation results show that clipping and filtering provides a better PAPR reduction than the others methods and only SLM technique conserve the PAPR reduction in reception part of signal.

The most prevalent hybrid additive manufacturing (HAM) method in the industry involves the combination of conventional processes, such as hot isostatic pressing or forging. In this way, a part is printed to its near-net-shape by additive manufacturing and then finished using open forge (Ampliforge). Hereby, the performance of the printed part will be improved by the downstream processes; this method also affords a reduction in time, cost, and waste material. In this study, the AISI 316L stainless steel parts were produced through selective laser melting (SLM) process and the cellular structure with columnar grains appeared. Then, hot compression experimental works were performed to investigate flow behavior, hot workability, density, and microstructure evolutions during the process. This process resulted in a near fully-dense part with a homogeneous microstructure without anisotropy of properties and higher hot deformation activation energy and peak stress in comparison with similar conventionally manufactured stainless steel.

Multimedia is the integration of text, graphics, sounds, images, animation and video with the computer mediated tools that can create a multisensory experience. In the recent times, traditional communication has been aided with new technology tools to facilitate effective teaching-learning process. Use of multimedia tools can enhance knowledge and make learning interesting which is otherwise limited within the printed texts. Moreover, with the evolution of technology in education, the learners are provided a number of options to choose upon. Use of two or more media enables the learners to gain more clarity in a particular topic/subject. Krishna Kanta Handiqui State Open University (KKHSOU) is providing print Self Learning Materials (SLM) as well as different multimedia instructional materials that include audio and audiovisual materials apart from a 24 hours community radio station and web radio. The study is intended to know about the use of multimedia instructional materials among the learners of the university. The research is descriptive in nature. Primary data was collected from three study centres of the University located in three different geographical locations. Questionnaires were provided to the learners and thus their responses were used to analyse the findings. The study will highlight some important facts like use of multimedia instructional materials, their preferences, difficulties faced while using them etc. A few suggestions as provided by the learners have also been underlined in the study.

- by Ankuran Dutta and +1
- •
- Instructional Design, Multimedia, Multimedia Communications, Multimedia Learning

Land degradation is intrinsically complex and involves decisions by many agencies and individuals, land degradation mapping
should be used as a learning tool through which managers, experts and stakeholders can re-examine their views within
a wider semantic context. In this paper, we introduce an analytical framework for mapping land degradation, developed
by World Overview for Conservation Approaches and technologies (WOCAT) programmes, which aims to develop some
thematic maps that serve as an useful tool and including effective information on land degradation and conservation status.
Consequently, this methodology would provide an important background for decision-making in order to launch rehabilitation/
remediation actions in high-priority intervention areas. As land degradation mapping is a problem-solving task that
aims to provide clear information, this study entails the implementation of WOCAT mapping tool, which integrate a set
of indicators to appraise the severity of land degradation across a representative watershed. So this work focuses on the
use of the most relevant indicators for measuring impacts of different degradation processes in El Mkhachbiya catchment,
situated in Northwest of Tunisia and those actions taken to deal with them based on the analysis of operating modes and
issues of degradation in different land use systems. This study aims to provide a database for surveillance and monitoring of
land degradation, in order to support stakeholders in making appropriate choices and judge guidelines and possible suitable
recommendations to remedy the situation in order to promote sustainable development. The approach is illustrated through
a case study of an urban watershed in Northwest of Tunisia. Results showed that the main land degradation drivers in the
study area were related to natural processes, which were exacerbated by human activities. So the output of this analytical
framework enabled a better communication of land degradation issues and concerns in a way relevant for policymakers.

- by ahlem gara
- •
- SLM, Land Degradation
- by Edward Buckley
- •
- Laser, Optical Communication, Display Technology, Laser Safety

Multiple inputs multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is an attractive transmission technique for high bit-rate communication systems. MIMO-OFDM has become a promising candidate for high performance 4G broadband wireless communications. One main disadvantage of OFDM is the high peak-to-average power ratio (PAPR) of the transmitter's output signal. Selected-Mapping (SLM) scheme which does not require the transmission of side information and can reduce the peak to average power ratio (PAPR) in turbo coded orthogonal frequency division multiplexing (OFDM) system is proposed. Simulation results show that the system can achieve significant reduction in PAPR and satisfactory bit error rate performance over AWGN channels. KEYWORDS Orthogonal Frequency Division Multiplexing (OFDM), peak-to-average-power-ratio (PAPR), Selective Mapping (SLM), Complementary Cummulative Distribution Function (CCDF), Bit Error Rate (BER).

- by Rakesh Saroj
- •
- Wireless Communications, SLM, Clipping, PAPR

It is shown that the lens count in a Fourier holographic projector can be reduced by encoding the equivalent lens
power in sets of Fresnel holograms. By using appropriately calculated Fresnel holograms in a reflective configuration
to effectively share a lens between the beam-expansion and demagnification stages of a holographic projector, a
reduction in lens count from four to one is demonstrated.

- by Edward Buckley
- •
- Optics, Digital Holography, Optical Communication, LCOS

OFDM (Orthogonal Frequency Division Multiplexing) has been raised a new modulation technique. Due to its advantages in multipath fading channel e.g. robust against ISI, ICI and some other advantages like best QoS for multiple users, efficient usage of bandwidth it is suggested to be the modulation technique for next generation 4G networks e.g. LTE. But along with all its advantages there are some disadvantages also e.g. High PAPR (Peak to Average Power Ratio) at the transmitter end and BER (Bit Error Rate) at the receiving end. Since OFDM is only used in the downlink of 4G networks. To reduce the problems of OFDM some techniques e.g. SLM, PTS, Clipping, Coding, & Pre-coding etc are suggested but none of them is reduce the PAPR and BER to an acceptable value. This Paper will discuss some techniques of PAPR & BER reduction, and their advantages and disadvantages in detail.

- by Abbadi Reda
- •
- Climate Change, Climatology, Adaptation, Environmental Sustainability

Orthogonal frequency division Multiplexing (OFDM) is one of the most popular multicarrier or multiplexing modulation techniques which transmits many signals over a single path in high speed wireless communication. OFDM convert high data rate stream in to smaller data rate stream. Due to this high data rate and ability to combat frequency selective fading, OFDM has a strong candidate for 4G wireless networks. Because of OFDM-MIMO advantages in multipath fading channel e.g. stout against ISI, ICI and some other advantages like best QoS for multiple users, efficient convention of bandwidth it is suggested to be the modulation technique for next generation 4G networks e.g. LTE. OFDM combined with multiple-input multiple-output (MIMO) to increase system capacity over the time variant frequency-selective channels and the diversity gain. The radio transmitter stations for covering and getting enough transmitted power in their desired area has to use High Power Amplifier (HPA) operable near to the saturation region or else, an aspect memory-less nonlinear distortion will affect the communication path. But along with all its advantages there are some disadvantages also. e.g. High PAPR (Peak to Average Power Ratio) at the transmitter end and BER (Bit Error Rate) at the receiving end. As OFDM is only used in the downlink of 4G networks. To reduce the problems of OFDM-MIMO systems some procedures as SLM, PTS, Clipping, Coding, & Pre-coding etc are suggested but none of them is proficient enough to reduce the PAPR and BER up to standard value. This Paper will discuss some techniques of PAPR reduction, and both their advantages and disadvantages.

- by IJEEE APM
- •
- Posttraumatic Stress Disorder (PTSD), MIMO-OFDM systems, SLM, Papringan Kaliwungu Kudus

The high PAPR is an OFDM system is arises because of IFFT operation, where data symbol across subcarrier can add up to produce a high peak value signal. In OFDM system, the peak deviation about average is significantly high, hence the signal level moves outside the dynamic range. Because in OFDM system we are loading the symbol in subcarrier and then take IFFT of this signal. This arises high PAPR, which limits use of OFDM in latest technological advancement such as 4G and 5G.This paper presents an idea to reduce PAPR in OFDM system using selected mapping (SLM) technique. When we want to convert a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequencies we need to apply Discrete Cosine Transform(DCT), and it is easiest way to do so.

- by ijsetr journal
- •
- OFDM, Cr, SLM, DCT

- by Donia Jendoubi
- •
- Geography, SLM, Land Degradation

When a light beam passes through a strongly atmospheric turbulence, phase singularities appear in some points of the wave front surface. For reconstruction of these beams or extracting topological charge of a pure Laguerre-Gaussian beam, it is needed to determine the center of the vorticities. In this work, we introduce a new method for this purpose by use of the wavefront slope value data. For a case, center of vortex beam and the selected origin for the coordinate system match together, the variance of determined topological charge to be minimized. Wavefront slops can be extracted with a wavefront sensor like a two-channel moiré based wavefront sensor. In experiment, lens phase function or a white noise are added to an azimuthally dependence phase of an incident beam. This is done by use of diffraction of a plane wave from a LCD, which is used as a spatial phase modulator. In addition, we used amplitude forked grating and allow passing diffracted beam through a turbulent medium. Then, we determined centers of these beams and noted some considerations for this process.

- by Mohammad Yeganeh and +1
- •
- SLM, Laguerre-Gaussian beams, Moiré Deflectometry, Topological Charge

The problem of peak-to-average power ratio (PAPR) reduction in orthogonal frequency-division multiplexing (OFDM) based massive multiple-input multiple-output (MIMO) downlink systems is considered. OFDM consist of large number of independent subcarriers, as a result of which the amplitude of such a signal can have high peak values. The peak to average power ratio of a transmitted signal is one of main challenges in OFDM or MIMO-OFDM. Understanding the effects of PAPR on OFDM and MIMO-OFDM systems is critical when determining what techniques to use improve system performance. Selective-Mapping (SLM) scheme which does not require the transmission of side information and can reduce the PAPR in OFDM system is proposed. SLM is a distortion less technique that can reduce PAPR efficiently without increase in power requirement and incurring data rate loss. Simulation results show that the system can achieve significant reduction in PAPR and satisfactory bit error rate performance over AWGN channels.

Purpose-The purpose of this paper is to eliminate Part defects and enrich additive manufacturing of ceramics. Laser powder bed fusion (L-PBF) experiments were carried to investigate the effects of laser parameters and selective oxidation of Titanium (mixed with TiO 2) on the microstructure, surface quality and melting state of Titania. The causes of several L-PBF parts defects were thoroughly analyzed. Design/methodology/approach-Laser power and scanning speed were varied within a specific range (50-125 W and 170-200 mm/s, respectively). Furthermore, varying loads of Ti (1%, 3%, 5% and 15%) were mixed with TiO 2 , which was selectively oxidized with laser beam in the presence of oxygen environment. Findings-Part defects such as cracks, pores and uneven grains growth were widely reduced in TiO 2 L-PBF specimens. Increasing the laser power and decreasing the scanning speed shown significant improvements in the surface morphology of TiO 2 ceramics. The amount of Ti material was fully melted and simultaneously changed into TiO 2 by the application of the laser beam. The selective oxidation of Ti material also improved the melting condition, microstructure and surface quality of the specimens. Originality/value-TiO 2 ceramic specimens were produced through L-PBF process. Increasing the laser power and decreasing the scanning speed is an effective way to sufficiently melt the powders and reduce parts defects. Selective oxidation of Ti by a high power laser beam approach was used to improve the manufacturability of TiO 2 specimens.

- by Asif Ur Rehman
- •
- Ceramic Engineering, Laser Physics, Ceramic Technology, Laser

We report about the implementation of the liquid crystal on silicon (LCOS) microdisplay with 1920 by 1080 resolution and 720 Hz frame rate. The driving solution is FPGA-based. The input signal is converted from the ultrahigh-resolution HDMI 2.0 signal into HD frames, which follow with the specified 720 Hz frame rate. Alternatively the signal is generated directly on the FPGA with built-in pattern generator. The display is showing switching times below 1.5 ms for the selected working temperature. The bit depth of the addressed image achieves 8 bit within each frame. The microdisplay is used in the fringe projection-based 3D sensing system, implemented by Fraunhofer IOF.

- by Grigory Lazarev
- •
- Liquid Crystals Over Silicon (LCOS), Spatial Light Modulator, LCOS, Projectors
- by Vernon Cole
- •
- Engineering, Materials Engineering, Mechanical Engineering, Chemical Engineering

Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multicarrier modulation scheme, which divides the entire frequency selective fading channel into many orthogonal narrow band flat fading sub channels. Orthogonal Frequency Division Multiplexing (OFDM) is considered to be a promising technique against the multipath fading channel for wireless communications [1]. However, OFDM faces the Peak-to-Average Power Ratio (PAPR) problem that is a major drawback of multicarrier transmission system. We will be using Selected Mapping method (SLM) to reduce PAPR, improve BER while maintain high SNR. MATLAB® simulation is used to implement the proposed model.

- by IJSTE - International Journal of Science Technology and Engineering
- •
- BER, SLM, Qam, SNR
- by Umathurai Saravanakumar
- •
- Wireless Communications, OFDM, SLM, PTS

An autostereoscopic display system, which allowed multiple viewers simultaneously by use of head-tracking, was previously demonstrated for TV applications in the ATTEST project. However, the requirement for a dynamically addressable, movable backlight presented several problems for the illumination source. In this paper, the authors demonstrate how the use of a novel laser-based holographic projection system can be used to address these problems.

- by Edward Buckley
- •
- Visual Display Design, Laser, Optical Communication, Autostereoscopic displays

Bangladesh is an agricultural country. Lands are intensively used for crop production with little or no fallow period. The most serious threat to sustainable agriculture is the depletion of soil organic matter which results in low productivity. Intensive agriculture affects soil fertility negatively mainly because of loss in soil organic matter. Sustainable practices like use of organic amendments is a useful tool to maintain or increase organic matter content in agricultural soils which contributes in preserving and improving soil fertility. Maintaining organic matter in the soil is the best choice for sustainable crop production to ensure food security of the burgeoning populations.

- by DR MD ALTAF HOSSAIN
- •
- SLM
- by Abbadi Reda
- •
- Soil Science, Agronomy, CPA, Agriculture
- by Edward Buckley
- •
- Optical Communication, LCOS, Eye Safety, SLM

Background: In the oral and maxillofacial surgery, fixation plates are commonly used for the stabilization of bone fragments. Additive manufacturing has enabled us to design and create personalized fixation devices that would ideally fit any given fracture. Aim: The aim of the present preliminary study was to assess the susceptibility of 3D-printed titanium fixation plates to biofilm formation. Methods: Plates were manufactured using selective laser melting (SLM) from Ti-6Al-4 V. Reference strains of Streptococcus mutans, Staphyloccocus epidermidis, Staphylococcus aureus, Lactobacillus rhamnosus, and Candida albicans, were tested to evaluate the material's susceptibility to biofilm formation over 48 hours. Biofilm formations were quantified by a colorimetric method and colony-forming units (CFU) quantification. Scanning electron microscopy (SEM) visualized the structure of the biofilm.

- by Lukas Palka
- •
- Microbiology, Oral Plaque Biofilms, Titanium, Additive Manufacturing

The reconfiguration time of a holographic beam-shaping device using a liquid crystal spatial light modulator (SLM) has been drastically decreased by five orders of magnitude to reach the microsecond range (~5 mu\mu mus). The method involves an acousto-optic modulator (AOM) placed in front of the SLM which points the laser beam towards different pre-addressed regions of the liquid crystal plate. Because the addressing signal is not changed, the reconfiguration time is mainly governed by the AOM response time. Moreover, this method allows us to clean up the transient regime by suppressing the bleed effect usually observed in the standard SLM reconfiguration.

- by Michael Mestre
- •
- Optical Communication, Spatial Light Modulator, LCOS, SLM
- by Leila Sahraoui
- •
- Computer Science, Distributed Computing, MIMO-OFDM systems, PTSD

In order to reduce error propagation effect of the self-synchronized scrambler-based selected mapping (SS-SLM), a partially self-synchronized scrambler-based selected mapping (PSS-SLM) was proposed in [5]—only most significant bits (MSBs) of QAM symbols are scrambled to reduce PAPR of OFDM signal. However, in the case when QPSK modulation is used, the PSS-SLM becomes equivalent to the original SS-SLM and thus cannot reduce error propagation effect of SS-SLM. In this paper, we propose a simple modification in the PSS-SLM for supporting QPSK modulation: it only scrambles data bits for the first half of QPSK symbols in each OFDM symbol. It will be shown through computer simulation that when QPSK modulation is used, the proposed scheme can reduce error propagation effect while keeping a similar PAPR reduction capability to the SS-SLM. I. INTRODUCTION The orthogonal frequency division multiplexing (OFDM) system is widely used in broadband wireless communication because of its robustness in a frequency selective fading environment. However, the OFDM signal, in which many carrier signals are combined in the time domain, is disadvantageous in that the peak-to-average power ratio (PAPR) becomes relatively large. In order to overcome this drawback, PAPR reduction techniques have been actively studied [1-5]. Among these PAPR reduction techniques, we consider selected mapping (SLM)-based schemes: SLM selects and transmits a signal having the smallest PAPR among candidate signals for the same information; it is simple in implementation and there is no distortion in the transmitted signal. When SLM is used, the receiver should be informed of the actually transmitted signal among the candidate signals. This information is referred to as side information (SI) of the SLM scheme. If this additional information is directly transmitted on a specific sub-carrier, the frequency efficiency of the OFDM system decreases. As a method to use SLM without explicit side information, [4] proposed a self-synchronized scrambler based SLM (SS-SLM) scheme employing a self-synchronized scrambler for generating candidate signals: the original data can be recovered without SI due to the feedback structure of the self-synchronized scrambler. However, error propagation in the receiver's descrambler causes an increased bit error rate (BER). In order to reduce such error propagation, [5] proposed a partially self-synchronized scrambler based SLM (PSS-SLM)—it scrambles only data bits being allocated to the most significant bits (MSBs) of in-phase and quadrature-phase components of each QAM symbol. However, in the case of QPSK modulation where all bits have the same significance, PSS-SLM becomes equivalent to the original SS-SLM which scrambles all data bits; therefore, PSS-SLM suffers from the error propagation phenomenon as SS-SLM does. In this paper, we propose a simple modification in the PSS-SLM for supporting QPSK modulation. Instead of separating data bits into MSBs and other bits in symbol mapping, the proposed scheme divides QPSK symbols in each OFDM symbol into two halves—the first half is scrambled and the other is not.

To reduce the occurrence of high peak-to-average power ratio (PAPR), this paper introduces prolate-binary sequences, and their application in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM). Through computer simulation, it is shown that the proposed prolate-binary sequences offer combined improved PAPR reduction performance, and reduced computational complexity compared with Riemann-binary sequences.

- by Saheed Adegbite and +1
- •
- Computational Complexity, Orthogonal Frequency Division Multiplexing (OFDM), Long Term Evolution (LTE), Ofdm Systems

This paper addresses the issue of high computational complexity associated with side information (SI) estimation in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM) to reduce peak-to-average power ratio (PAPR). The proposed method is based on a slightly modified SLM approach that enables the use of a low complexity binary detection criterion for SI estimation, without the need for SI transmission. Simulations show that the combined PAPR reduction and BER performance of the proposed method is similar to both pilot-assisted Maximum-Likelihood (PAML) SI estimation scheme and standard SLM that presumes perfect knowledge of SI. In addition, relative to the PAML scheme, the proposed method offers significantly reduced computational complexity.

- by Mr. Aditya Kumar (Assistant professor)
- •
- BER, SLM, Computer Applications, PAPR

Using of welding technologies to produce metal volume objects allows considerable lowering of their manufacturing cost at simultaneous increase in productivity, compared to SLS-and SLM-processes. The most perspective welding technology of additive manufacturing of three-dimensional objects is plasma-arc technology with application of wires or powders. It allows creating at comparatively low heat input quality volumetric products with wall thickness from 3 to 50 mm from alloys based on Fe, Ni, Co, Cu, Ti, Al, as well as composite materials, containing refractory components.

- by Korzhyk Volodymyr
- •
- Mechanical Engineering, Robotics, Materials Science, Welding Engineering

Existing for almost four decades, liquid crystal on Silicon (LCOS) technology is rapidly growing into photonic applications. We review the basics of the technology, from the wafer to the driving solutions, the progress over the last decade and the future outlook. Furthermore we review the most exciting industrial and scientific applications of the LCOS technology.

This paper presents a qualitative, real-time backlighting positioning sensor for the alignment of an optical beam to a minutely deviated diffraction order axis to increase the power coupling efficiency into a multimode fiber in selective launches. Results show that the technique facilitates the alignment of the lenses to the first diffraction order axis and improves the power coupling efficiency into a multimode fiber.

... After modulating the phase, the beam is passed through a lens (f = 250 mm) which performs the Fourier transform. ... 9. D. Palima and V. Daria, "Holographic projection of arbitrary light patterns with a suppressed zeroorder... more

- by Giovanni Tapang
- •
- Optics, Optical Communication, Local Area Networks, Spatial Light Modulator