Iet Optoelectronics最新文献

{"title":"Theoretical analysis of the electrical characteristics of lead-free formamidinium tin iodide solar cell","authors":"Elizabeth K. Katunge,&nbsp;George G. Njema,&nbsp;Joshua K. Kibet","doi":"10.1049/ote2.12104","DOIUrl":"https://doi.org/10.1049/ote2.12104","url":null,"abstract":"<p>Green energy transition and climate change have gathered significant momentum in the world because of the rising population and increased clean energy demands. For this reason, renewable energy alternatives such as inexhaustible photo energy from the sun appear to be the ultimate solution to the world's energy needs. Formamidinium tin tri-iodide (HC(NH₂)₂SnI₃)-based perovskites are found to be more efficient and stable than their methylammonium tin tri-iodide (MASnI₃) counterparts because of its wider bandgap and better temperature stability. A device simulation of FASnI₃-based solar cell is numerically performed using solar cell capacitance simulator (SCAPS-1D). The focus is to investigate the effect of changing working temperature, metal back contact, absorber thickness, defect density, and doping concentration on the performance of the proposed solar cell device. The optimised solar cell parameters of the proposed solar cell were: short-circuit current density (Jsc) of 28.45 mAcm⁻², open-circuit voltage (Voc) of 1.0042 V, fill factor of 63.73%, and power conversion efficiency of 18.21% at 300 K, thus, paving the way for novel perovskite solar cells which are environmentally benign because they are lead-free, have better absorption efficiency, and can be injected into the production work flow for commercial applications.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 5","pages":"220-236"},"PeriodicalIF":1.6,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50133286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electro-optical spiking neural networks using an enhanced optical axon with pulse amplitude modulation and automatic gain controller","authors":"George-Iulian Uleru,&nbsp;Mircea Hulea,&nbsp;Othman Isam Younus,&nbsp;Zabih Ghassemlooy,&nbsp;Sujan Rajbhandari","doi":"10.1049/ote2.12101","DOIUrl":"10.1049/ote2.12101","url":null,"abstract":"<p>Visible light communication can be leveraged to establish a wireless link between neurons in spiking networks even when neural areas are in relative motions. In electro-optical spiking neural networks (SNN), parallel transmission is often achieved through wavelength division multiplexing (WDM). However, WDM can be prohibitive in certain applications due to the need for multiple narrow-band transmitters and receivers with optical bandpass filters. Instead of WDM, an alternative approach of using non-orthogonal multiple access is explored (NOMA) with a pulse amplitude modulation (PAM) scheme in optical axons to enable parallel neural paths in an SNN. To evaluate NOMA with PAM, the authors implement an electro-optical SNN that controls the force of two anthropomorphic fingers actuated by the shape memory alloy-based actuators. An optical reference channel is used to dynamically adjust the optical receiver's gain to improve the receiver's decoding performance. Experimental results demonstrate that the electro-optical SNN can maintain control over the fingers and hold an object under varying channel conditions. Hence, the proposed system offers robustness against dynamic optical channels induced by the relative motion of neurons.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"175-183"},"PeriodicalIF":1.6,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42958994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guest Editorial: Selected papers from the 8th Biennial Colloquium & 6th International Workshop on Optical Wireless Communications","authors":"Mónica Jorge Carvalho de Figueiredo,&nbsp;Stanislav Zvanovec,&nbsp;Rafael Pérez-Jiménez,&nbsp;Luis Filipe Mesquita Nero Moreira Alves","doi":"10.1049/ote2.12103","DOIUrl":"https://doi.org/10.1049/ote2.12103","url":null,"abstract":"&lt;p&gt;Since 2011, optical wireless communication (OWC) technologies have gained momentum. OWC has been supported by an active research community, and entrepreneurs who have shown the merits of these technologies by showcasing real-time demonstrators and commercial OWC solutions. These technologies include visible light communications (VLC), underwater VLC, Li-Fi, optical camera communications (OCC), visible light positioning, visible light sensing and free space optics, among others. They have been shown to be an efficient means to satisfy the demanding requirements of backhaul and access network levels, and also to provide a means for accurate indoor positioning and sensing, or enable wireless communication in non-RF friendly environments. As a result, it is envisaged to become an indispensable part of 6G and will complement other communication methods to benefit our daily lives. This Special Issue contains a group of 10 selected papers accepted at the 8th Colloquium &amp; 6th International Workshop on Optical Wireless Communications, co-located with the International Symposium on Communication Systems, Networks &amp; Digital Signal Processing (CSNDSP 2022). This Special Issue has provided the best paper authors' the opportunity to extend their work beyond what was presented at this event, enabling new results and development to further advance the respective fields.&lt;/p&gt;&lt;p&gt;Accepted papers can be clustered into three main categories, namely theoretical, applications and performance oriented. The papers lying in the first category exhibit novelties in modelling of optical wireless channel, non-linear effects and synchronisation issues. The papers in this category are of Combeau et al., Vieira et al., and Rodrigues et al. The second category of papers presents different approaches to using OWC concepts in short and medium range applications. These papers are of Younus et al., Rêgo et al., and Uleru et al. The last category proposes new techniques to evaluate performance in systems employing OWC concepts, such as screen to the camera, light-emitting diode (LED) to multispectral camera, LED matrix arrays or reconfigurable intelligent surface (RIS) based OWC. These papers are of Yokar et al., Moreno et al., Mohammadi et al., and Salehiyan et al. A brief presentation of each of the paper in this Special Issue follows.&lt;/p&gt;&lt;p&gt;In paper 1, Combeau et al. propose a method for the optical characterisation of materials to enable realistic channel simulation based on Monte-Carlo Ray-Tracing algorithms. They conduct some experimental measurements in environments containing the materials sought and then apply an optimisation algorithm which searches for the parameters of the material reflection models. Therefore minimising the difference between the optical measurement and the simulation. Results show that the proposed method produces a correct estimate of the Bidirectional Reflectance Distribution Function albedos, provided that the models correspond well to the r","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"87-90"},"PeriodicalIF":1.6,"publicationDate":"2023-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50129415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation technique for screen-to-camera-based optical camera communications","authors":"Vaigai Nayaki Yokar,&nbsp;Hoa Le-Minh,&nbsp;Zabih Ghassemlooy,&nbsp;Wai Lok Woo","doi":"10.1049/ote2.12102","DOIUrl":"10.1049/ote2.12102","url":null,"abstract":"<p>The increasing development and utilisation of optical camera communications offer an excellent opportunity for the implementation of the smartphone-to-smartphone-based visible light communications (S2SVLC) system. In this study, the authors experimentally demonstrate that the S2SVLC system can support high-quality multimedia transmissions by the investigation of the mean square error estimation, peak signal-to-noise (PSNR) degradation, bit error rate (BER), and data rate achieved. The experimental analysis has been carried out for different typical practical background illuminations (i.e., normal illumination and dark condition), distances, tilting, and rotation angles. The PSNR and BER are determined for different frame sizes in the S2SVLC system to provide an insight of system performance. Those results indicate that the data transmission at different conditions significantly impacts the system's performance.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"184-193"},"PeriodicalIF":1.6,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48840843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frame recovery using multiple images in rolling shutter based systems","authors":"Miguel Rêgo,&nbsp;Joaquin Perez,&nbsp;Pedro Fonseca,&nbsp;Luís Nero Alves","doi":"10.1049/ote2.12100","DOIUrl":"10.1049/ote2.12100","url":null,"abstract":"<p>An algorithm for recovering transmitted static identifiers (IDs) in rolling shutter based Optical Camera Communication systems is proposed by the authors, considering a system comprised of a camera and a circular light source. The goal is to allow the correct decoding when the ID frame is only partially detected in the image. A baseline algorithm as reference for the frame recovery success rate (FRSR) and a reconstruction algorithm based on the idea of capturing multiple frame fragments and reassembling them is proposed in order to recover the transmitted ID not entirely seen on a single image. It was proven, by simulation, that the maximum distance at which the IDs recovery can be guaranteed is increased by 2.5 fold with the proposed algorithm, for 6-bit, 8-bit and 10-bit codewords. An experimental validation algorithm was also proposed, using image processing techniques to extract the bitstreams and test the ID recovery process. The proposed algorithm improves the FRSR for a given distance, even in the presence of considerable bit errors in the bitstreams extracted from the images.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"162-174"},"PeriodicalIF":1.6,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12100","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46632629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An optical digital-to-analog converter with a built-in intensity converter consisting of silicon waveguide","authors":"Yohei Aikawa,&nbsp;Hiroyuki Uenohara","doi":"10.1049/ote2.12099","DOIUrl":"10.1049/ote2.12099","url":null,"abstract":"<p>Optical digital-to-analog converters (DACs) are key to overcoming the enormous power consumption caused by the slowdown of Moore's Law. In previous work, an optical DAC consisting of a signal generator and an intensity converter was presented. The generating component was integrated into the device, but a higher level of device integration is desirable. An optical DAC device with a built-in intensity converter for a 2-bit binary phase-shift keying (BPSK) signal is demonstrated. The integrated device consists of two delay line interferometers (DLIs) with silicon waveguides. The first is used to generate a quadrature PSK (QPSK) signal from two BPSK signals, and the second is used to convert the QPSK constellation into light intensities. Experimental results show that the 2-bit digital codes 00, 01, 10, and 11 can be successfully converted into four different light intensities depending on their pattern at 10 Gbps.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 5","pages":"214-219"},"PeriodicalIF":1.6,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12099","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43268937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Material characterisation for optical wireless communication combining measurement and Monte Carlo simulations","authors":"Pierre Combeau,&nbsp;Lilian Aveneau,&nbsp;Pierre Thuillier Le Gac,&nbsp;Ruqin Xiao","doi":"10.1049/ote2.12098","DOIUrl":"10.1049/ote2.12098","url":null,"abstract":"<p>A method is proposed for optical characterisation of materials, which is a very important input for realistic channel simulation based on Monte-Carlo Ray-Tracing algorithms. This original approach consists first of all in carrying out some measurements of the optical power received after propagation in the environment containing the materials sought, using a simple and low-cost experimental setup. In a second step, this approach is based on an optimization algorithm. It takes as input the optical power measurements made, associated with the parameters of the measurement environment, such as the positions or properties of the sensors. This algorithm searches for the parameters of the material reflection models, minimising the difference between the optical measurement and the simulation. Two cost functions are studied to perform this search and showed that the correlation measure is the more robust one. To avoid uncertainties in the real input data, this approach is discussed using only a virtual configuration with well-controlled input data and thus a virtual measurement obtained by simulation. The results show that this method produces a correct estimate of the Bidirectional Reflectance Distribution Function (BRDF) albedos, provided that the chosen BRDF models correspond well to the reflection behaviour of the materials, and that the materials have a significant influence on the measured optical power.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"149-161"},"PeriodicalIF":1.6,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45729357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-linear modelling and distortion compensation in optical Fast-orthogonal frequency division multiplexing systems","authors":"Luis Carlos Vieira,&nbsp;Waseem Ozan,&nbsp;John Mitchell,&nbsp;Izzat Darwazeh","doi":"10.1049/ote2.12097","DOIUrl":"10.1049/ote2.12097","url":null,"abstract":"<p>Fast-OFDM-based intensity-modulation and direct-detection (IM/DD) has been proposed for deployment of cost-efficient optical access networks, due to its implementation simplicity and high spectral efficiency. In this article, the accuracy of the generalised memory polynomial (GMP) for the non-linear modelling of optical Fast-OFDM links is studied, including memory effects and considering different model parameters. After model validation using measured data of a 10 km single mode fibre link, the GMP is used for performance investigations of a distortion compensation approach to optical Fast-OFDM, for up to 16PAM modulation formats and different number of Fast-OFDM subcarriers. This study firstly reports the performance results of optical 16PAM-Fast-OFDM systems using either 2PAM- or 4PAM-based training signals for digital post-distortion and FFT-based channel estimation, and firstly investigates the influence of the zero padding (ZP) length on the performance of optical Fast-OFDM. Excellent performance improvements are achieved using the proposed distortion compensation scheme, relative to conventional system implementation.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"139-148"},"PeriodicalIF":1.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12097","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46380433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A unilateral 3D indoor positioning system employing optical camera communications","authors":"Othman Isam Younus,&nbsp;Neha Chaudhary,&nbsp;Zabih Ghassemlooy,&nbsp;Luis Nero Alves,&nbsp;Stanislav Zvanovec,&nbsp;Dimitrios Pattas,&nbsp;Vasilis K. Papanikolaou","doi":"10.1049/ote2.12094","DOIUrl":"10.1049/ote2.12094","url":null,"abstract":"<p>This article investigates the use of a visible light positioning system in an indoor environment to provide a three dimensional (3D) high-accuracy solution. The proposed system leveraged the use of a single light-emitting diode and an image sensor at the transmitter and the receiver (Rx) respectively. The proposed system can retrieve the 3D coordinate of the Rx using a combination of the angle of arrival and received signal strength (RSS). To mitigate the error induced by the lens at the Rx, a novel method is proposed and experimentally tested. The authors show that, the proposed method outperforms previously reported RSS under all circumstances and it is immune to varying exposure times within the standard range of 250 µs to 4 ms. The authors experimentally demonstrate that the proposed algorithm can achieve a 3D root mean squared error of 7.56 cm.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"110-119"},"PeriodicalIF":1.6,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12094","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49452882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multispectral Optical camera communication links based on spectral signature multiplexing","authors":"Daniel Moreno,&nbsp;Victor Guerra,&nbsp;Julio Rufo,&nbsp;Jose Rabadan,&nbsp;Rafael Perez-Jimenez","doi":"10.1049/ote2.12090","DOIUrl":"https://doi.org/10.1049/ote2.12090","url":null,"abstract":"<p>Optical camera communication is foreseen to have an essential role in future systems requiring wireless communication capability. In this regard, high-spectral-resolution cameras, such as multispectral (MS) cameras, present specific characteristics that can be exploited to provide new features to optical camera communication links. Using the MS cameras' features to take advantage of the light-emitting diode (LED) behaviour in a novel communication scheme is focussed. Notably, LED spectral response curves are different when their temperature changes. Therefore, these differences can be detected based on the MS cameras' spectral resolution. Thus, more than one communication channel can be attained using the same LED device since the camera can distinguish the different LED spectral signatures. This new approach is analysed in this work, including some equalisation techniques applied to the channel matrix in the receiver to improve the extraction of the transmitted signal reducing the inter-channel interference. For the specific MS camera employed in the experiments, up to two distinct channels could be obtained with the same transmitter at different temperatures, getting a bit error rate below the forward error correction limit. However, obtaining satisfactory results is highly dependent on the variation that temperature causes in the spectral signatures of the LEDs, so further experiments are recommended in future work with different devices.</p>","PeriodicalId":13408,"journal":{"name":"Iet Optoelectronics","volume":"17 4","pages":"91-100"},"PeriodicalIF":1.6,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ote2.12090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50125223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}