Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.139530
L. Sharma, R. Sharma
https://doi.org/10.24425/opelre.2021.13953
https://doi.org/10.24425/opelre.2021.13953
{"title":"Design and analytical calculations of the width and arrangement of quantum well and barrier layers in GaN/AlGaN LED to enhance the performance","authors":"L. Sharma, R. Sharma","doi":"10.24425/opelre.2021.139530","DOIUrl":"https://doi.org/10.24425/opelre.2021.139530","url":null,"abstract":"https://doi.org/10.24425/opelre.2021.13953","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89318468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.139482
M. Grábner, P. Honzátko
Article history: Received 10 Sep. 2021 Received in revised form 22 Oct. 2021 Accepted 23 Oct. 2021 Available online 12 Nov. 2021 High power fibre lasers need to be cooled efficiently to avoid their thermal damage. Temperature distribution in fibre should be estimated during the fibre laser design process. The steady-state heat equation in a cylindrical geometry is solved to derive a practical formula for temperature radial distribution in multi-layered optical fibres with arbitrary number of the layers. The heat source is located in one or more cylindrical domains. The validity of the analytical formula is tested by comparison with static heat transfer simulations of typical application examples including octagonal double clad fibre, air-clad fibre, fibre with nonuniform, microstructured core. The accuracy sufficient for practical use is reported even for cases with not exactly cylindrical domains.
{"title":"Formula for temperature distribution in multi-layer optical fibres for high-power fibre lasers","authors":"M. Grábner, P. Honzátko","doi":"10.24425/opelre.2021.139482","DOIUrl":"https://doi.org/10.24425/opelre.2021.139482","url":null,"abstract":"Article history: Received 10 Sep. 2021 Received in revised form 22 Oct. 2021 Accepted 23 Oct. 2021 Available online 12 Nov. 2021 High power fibre lasers need to be cooled efficiently to avoid their thermal damage. Temperature distribution in fibre should be estimated during the fibre laser design process. The steady-state heat equation in a cylindrical geometry is solved to derive a practical formula for temperature radial distribution in multi-layered optical fibres with arbitrary number of the layers. The heat source is located in one or more cylindrical domains. The validity of the analytical formula is tested by comparison with static heat transfer simulations of typical application examples including octagonal double clad fibre, air-clad fibre, fibre with nonuniform, microstructured core. The accuracy sufficient for practical use is reported even for cases with not exactly cylindrical domains.","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87180072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.139753
S. Hussin, E. M. Shalaby
In this paper, the effect of an indoor visible light communication channel is studied. Moreover, the analysis of the received power distribution of the photodiode in the line of sight and the first reflection of the channel without line of sight with several parameters is simulated. Two different waveforms are explained in detail. Orthogonal frequency division multiplexing has been widely adopted in radio frequency and optical communication systems. One of the most important disadvantages of the orthogonal frequency division multiplexing signal is the high peak-to-average power ratio. Therefore, it is important to minimize the peak-to-average power ratio in the visible light communication systems more than in radio-frequency wireless applications. In the visible light communication systems, the high peak-to-average power ratio produces a high DC bias which reduces power efficiency of the system. A discrete Fourier transform spread orthogonal frequency division multiplexing is proposed to be used in wireless communication systems; its ability to minimize peak-to-average power ratio has been tested. The analysis of two different subcarrier allocation methods for the discrete Fourier transform-spread subcarriers, as well as the examination of two distinct subcarrier allocation strategies, distributed and localized mapping, are investigated and studied. The effects of an accurate new sub-band mapping for the localized discrete Fourier transform spread orthogonal frequency division multiplexing scheme are presented in this paper. The light-fidelity system performance of the orthogonal frequency division multiplexing and discrete Fourier transform spread orthogonal frequency division multiplexing with different sub-mapping techniques are simulated with Matlab™. A system performance size of bit error rate and peak-to-average power ratio are obtained, as well.
{"title":"Performance analysis of DFT-S-OFDM waveform for Li-Fi systems","authors":"S. Hussin, E. M. Shalaby","doi":"10.24425/opelre.2021.139753","DOIUrl":"https://doi.org/10.24425/opelre.2021.139753","url":null,"abstract":"In this paper, the effect of an indoor visible light communication channel is studied. Moreover, the analysis of the received power distribution of the photodiode in the line of sight and the first reflection of the channel without line of sight with several parameters is simulated. Two different waveforms are explained in detail. Orthogonal frequency division multiplexing has been widely adopted in radio frequency and optical communication systems. One of the most important disadvantages of the orthogonal frequency division multiplexing signal is the high peak-to-average power ratio. Therefore, it is important to minimize the peak-to-average power ratio in the visible light communication systems more than in radio-frequency wireless applications. In the visible light communication systems, the high peak-to-average power ratio produces a high DC bias which reduces power efficiency of the system. A discrete Fourier transform spread orthogonal frequency division multiplexing is proposed to be used in wireless communication systems; its ability to minimize peak-to-average power ratio has been tested. The analysis of two different subcarrier allocation methods for the discrete Fourier transform-spread subcarriers, as well as the examination of two distinct subcarrier allocation strategies, distributed and localized mapping, are investigated and studied. The effects of an accurate new sub-band mapping for the localized discrete Fourier transform spread orthogonal frequency division multiplexing scheme are presented in this paper. The light-fidelity system performance of the orthogonal frequency division multiplexing and discrete Fourier transform spread orthogonal frequency division multiplexing with different sub-mapping techniques are simulated with Matlab™. A system performance size of bit error rate and peak-to-average power ratio are obtained, as well.","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82241168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.139756
A. Krzyzanowska, R. Szczygiel
Article history: Received 10 Sep. 2021 Received in revised form 30 Oct. 2021 Accepted 2 Nov. 2021 Available online 15 Dec. 2021 Hybrid pixel radiation detectors with a direct photon-to-charge conversion working in a single photon counting mode have gained increasing attention due to their high dynamic range and noiseless imaging. Since sensors of different materials can be attached to readout electronics, they enable work with a wide range of photon energies. The charge-sharing effect observed in segmented devices, such as hybrid pixel detectors, is a phenomenon that deteriorates both spatial resolution and detection efficiency. Algorithms that allow the detection of a photon irrespective of the charge-sharing effect are proposed to overcome these limitations. However, the spatial resolution of the detector can be further improved beyond the resolution determined by the pixel size if information about the charge proportions collected by neighbouring pixels is used to approximate the interaction position. In the article, an approach to achieve a subpixel resolution in a hybrid pixel detector working in the single photon counting mode is described. Requirements and limitations of digital inter-pixel algorithms which can be implemented on-chip are studied. In the simulations, the factors influencing the detector resolution are evaluated, including size of a charge cloud, number of virtual pixel subdivisions, and detector parameters.
{"title":"Simulation study on improving the spatial resolution of photon-counting hybrid pixel X-ray detectors","authors":"A. Krzyzanowska, R. Szczygiel","doi":"10.24425/opelre.2021.139756","DOIUrl":"https://doi.org/10.24425/opelre.2021.139756","url":null,"abstract":"Article history: Received 10 Sep. 2021 Received in revised form 30 Oct. 2021 Accepted 2 Nov. 2021 Available online 15 Dec. 2021 Hybrid pixel radiation detectors with a direct photon-to-charge conversion working in a single photon counting mode have gained increasing attention due to their high dynamic range and noiseless imaging. Since sensors of different materials can be attached to readout electronics, they enable work with a wide range of photon energies. The charge-sharing effect observed in segmented devices, such as hybrid pixel detectors, is a phenomenon that deteriorates both spatial resolution and detection efficiency. Algorithms that allow the detection of a photon irrespective of the charge-sharing effect are proposed to overcome these limitations. However, the spatial resolution of the detector can be further improved beyond the resolution determined by the pixel size if information about the charge proportions collected by neighbouring pixels is used to approximate the interaction position. In the article, an approach to achieve a subpixel resolution in a hybrid pixel detector working in the single photon counting mode is described. Requirements and limitations of digital inter-pixel algorithms which can be implemented on-chip are studied. In the simulations, the factors influencing the detector resolution are evaluated, including size of a charge cloud, number of virtual pixel subdivisions, and detector parameters.","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90638295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2020.134459
A. Rogalski, M. Kopytko, P. Martyniuk
Article history: Received 05 May 2020 Received in revised form 16 Jun. 2020 Accepted 08 Jul. 2020 Graphene applications in electronic and optoelectronic devices have been thoroughly and intensively studied since graphene discovery. Thanks to the exceptional electronic and optical properties of graphene and other two-dimensional (2D) materials, they can become promising candidates for infrared and terahertz photodetectors. Quantity of the published papers devoted to 2D materials as sensors is huge. However, authors of these papers address them mainly to researches involved in investigations of 2D materials. In the present paper this topic is treated comprehensively with including both theoretical estimations and many experimental data. At the beginning fundamental properties and performance of graphene-based, as well as alternative 2D materials have been shortly described. Next, the position of 2D material detectors is considered in confrontation with the present stage of infrared and terahertz detectors offered on global market. A new benchmark, so-called “Law 19”, used for prediction of background limited HgCdTe photodiodes operated at near room temperature, is introduced. This law is next treated as the reference for alternative 2D material technologies. The performance comparison concerns the detector responsivity, detectivity and response time. Place of 2D material-based detectors in the near future in a wide infrared detector family is predicted in the final conclusions.
{"title":"2D material infrared and terahertz detectors: status and outlook","authors":"A. Rogalski, M. Kopytko, P. Martyniuk","doi":"10.24425/opelre.2020.134459","DOIUrl":"https://doi.org/10.24425/opelre.2020.134459","url":null,"abstract":"Article history: Received 05 May 2020 Received in revised form 16 Jun. 2020 Accepted 08 Jul. 2020 Graphene applications in electronic and optoelectronic devices have been thoroughly and intensively studied since graphene discovery. Thanks to the exceptional electronic and optical properties of graphene and other two-dimensional (2D) materials, they can become promising candidates for infrared and terahertz photodetectors. Quantity of the published papers devoted to 2D materials as sensors is huge. However, authors of these papers address them mainly to researches involved in investigations of 2D materials. In the present paper this topic is treated comprehensively with including both theoretical estimations and many experimental data. At the beginning fundamental properties and performance of graphene-based, as well as alternative 2D materials have been shortly described. Next, the position of 2D material detectors is considered in confrontation with the present stage of infrared and terahertz detectors offered on global market. A new benchmark, so-called “Law 19”, used for prediction of background limited HgCdTe photodiodes operated at near room temperature, is introduced. This law is next treated as the reference for alternative 2D material technologies. The performance comparison concerns the detector responsivity, detectivity and response time. Place of 2D material-based detectors in the near future in a wide infrared detector family is predicted in the final conclusions.","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72366782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.135824
G. Bieszczad, S. Gogler, J. Świderski
Article history: Received 23 Nov. 2020 Received in revised form 2 Jan. 2021 Accepted 7 Jan. 2021 Thermal-imaging systems respond to infrared radiation that is naturally emitted by objects. Various multispectral and hyperspectral devices are available for measuring radiation in discrete sub-bands and thus enable a detection of differences in a spectral emissivity or transmission. For example, such devices can be used to detect hazardous gases. However, their operation principle is based on the fact that radiation is considered a scalar property. Consequently, all the radiation vector properties, such as polarization, are neglected. Analysing radiation in terms of the polarization state and the spatial distribution of thereof across a scene can provide additional information regarding the imaged objects. Various methods can be used to extract polarimetric information from an observed scene. We briefly review architectures of polarimetric imagers used in different wavebands. First, the state-of-the-art polarimeters are presented, and, then, a classification of polarimetricmeasurement devices is described in detail. Additionally, the data processing in Stokes polarimeters is given. Emphasis is laid on the methods for obtaining the Stokes parameters. Some predictions in terms of LWIR polarimeters are presented in the conclusion.
{"title":"Review of design and signal processing of polarimetric imaging cameras","authors":"G. Bieszczad, S. Gogler, J. Świderski","doi":"10.24425/opelre.2021.135824","DOIUrl":"https://doi.org/10.24425/opelre.2021.135824","url":null,"abstract":"Article history: Received 23 Nov. 2020 Received in revised form 2 Jan. 2021 Accepted 7 Jan. 2021 Thermal-imaging systems respond to infrared radiation that is naturally emitted by objects. Various multispectral and hyperspectral devices are available for measuring radiation in discrete sub-bands and thus enable a detection of differences in a spectral emissivity or transmission. For example, such devices can be used to detect hazardous gases. However, their operation principle is based on the fact that radiation is considered a scalar property. Consequently, all the radiation vector properties, such as polarization, are neglected. Analysing radiation in terms of the polarization state and the spatial distribution of thereof across a scene can provide additional information regarding the imaged objects. Various methods can be used to extract polarimetric information from an observed scene. We briefly review architectures of polarimetric imagers used in different wavebands. First, the state-of-the-art polarimeters are presented, and, then, a classification of polarimetricmeasurement devices is described in detail. Additionally, the data processing in Stokes polarimeters is given. Emphasis is laid on the methods for obtaining the Stokes parameters. Some predictions in terms of LWIR polarimeters are presented in the conclusion.","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81944632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2020.132499
{"title":"Numerical procedures and their practical application in PV module analyses. Part III: parameters of atmospheric transparency – determining and correlations","authors":"","doi":"10.24425/opelre.2020.132499","DOIUrl":"https://doi.org/10.24425/opelre.2020.132499","url":null,"abstract":"","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84036269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2021.139755
{"title":"Symmetrical and asymmetrical imino-naphthalimides in perovskite solar cells","authors":"","doi":"10.24425/opelre.2021.139755","DOIUrl":"https://doi.org/10.24425/opelre.2021.139755","url":null,"abstract":"","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89235476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.24425/opelre.2022.141542
{"title":"Design of external microtextures for efficient light outcoupling in OLEDs with different preferential orientation of emission dipoles","authors":"","doi":"10.24425/opelre.2022.141542","DOIUrl":"https://doi.org/10.24425/opelre.2022.141542","url":null,"abstract":"","PeriodicalId":54670,"journal":{"name":"Opto-Electronics Review","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80286391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：