Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446942
K. Chuah, Khoonchew Chuah, S. Harun, H. Ahmad
The profile and etch depth of silica waveguide channel are inspected and measured with microscope and surface profiler respectively. Hexafluoroethane (C2F6) and tetrafluoromethane (CF4) plasma etching conditions were investigated for planar lightwave circuit (PLC) requirement. From the microscope images, suspected insufficient height of waveguide channel and chromium mask etch-off problem occurred after ICP etching by using CF4etch gas. By changing the fluorocarbon etch gas from CF4 to C2F6, chromium mask remained after etching process and found that there are some improvement of waveguide channel profile and selective etch for the etch results. The aim of 8 micron waveguide channel height is achieved by using C2F6 gas in ICP etching. This is agreed with process knowledge that fluorocarbon etch gas C2F6 is better than CF4 and suit the need for planar lightwave circuit silica etching process.
{"title":"Inductively coupled plasma of fluorocarbon plasma glass etching process on planar lightwave circuit device fabrication","authors":"K. Chuah, Khoonchew Chuah, S. Harun, H. Ahmad","doi":"10.1109/ICTONMW.2007.4446942","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446942","url":null,"abstract":"The profile and etch depth of silica waveguide channel are inspected and measured with microscope and surface profiler respectively. Hexafluoroethane (C<sub>2</sub>F<sub>6</sub>) and tetrafluoromethane (CF<sub>4</sub>) plasma etching conditions were investigated for planar lightwave circuit (PLC) requirement. From the microscope images, suspected insufficient height of waveguide channel and chromium mask etch-off problem occurred after ICP etching by using CF<sub>4</sub>etch gas. By changing the fluorocarbon etch gas from CF<sub>4</sub> to C<sub>2</sub>F<sub>6</sub>, chromium mask remained after etching process and found that there are some improvement of waveguide channel profile and selective etch for the etch results. The aim of 8 micron waveguide channel height is achieved by using C<sub>2</sub>F<sub>6</sub> gas in ICP etching. This is agreed with process knowledge that fluorocarbon etch gas C<sub>2</sub>F<sub>6</sub> is better than CF<sub>4</sub> and suit the need for planar lightwave circuit silica etching process.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115187107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446973
G. Beziuk, A. Grobelny, E. Plinski, J. Witkowski
Terahertz sources and characterisation of the THz radiation are briefly reviewed. Technique of the THz photomixing is described.
本文简要介绍了太赫兹源和太赫兹辐射的特性。介绍了太赫兹光混合技术。
{"title":"THz optical mixer","authors":"G. Beziuk, A. Grobelny, E. Plinski, J. Witkowski","doi":"10.1109/ICTONMW.2007.4446973","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446973","url":null,"abstract":"Terahertz sources and characterisation of the THz radiation are briefly reviewed. Technique of the THz photomixing is described.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129860848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446945
M. Najjar, H. Rezig, A. Bouallègue
In this paper we describe the technical issues of access and metro networks based on wavelength division multiplexing (WDM) technologies, some studies are done to precise the effect of different parameters over the quality of transmission by measuring the bit error ratio (BER). A WDM star access network with colorless optical network units (ONUs) is a known model of access network. For realizing the colorless ONU, two approaches are introduced; optical carrier supply and spectrum slicing. In addition, a WDM metro ring network with scalable optical add/drop multiplexers (OADMs), namely the tapped-type OADM, is proposed to effectively accommodate the large amount of traffic issued from access networks. Prototype is studied and analyzed to verify the efficiency of WDM technologies in such access networks.
{"title":"Design and characterization of WDM ring access network","authors":"M. Najjar, H. Rezig, A. Bouallègue","doi":"10.1109/ICTONMW.2007.4446945","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446945","url":null,"abstract":"In this paper we describe the technical issues of access and metro networks based on wavelength division multiplexing (WDM) technologies, some studies are done to precise the effect of different parameters over the quality of transmission by measuring the bit error ratio (BER). A WDM star access network with colorless optical network units (ONUs) is a known model of access network. For realizing the colorless ONU, two approaches are introduced; optical carrier supply and spectrum slicing. In addition, a WDM metro ring network with scalable optical add/drop multiplexers (OADMs), namely the tapped-type OADM, is proposed to effectively accommodate the large amount of traffic issued from access networks. Prototype is studied and analyzed to verify the efficiency of WDM technologies in such access networks.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122207676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446943
A. Ananenkov, A. Konovaltsev, A. Kukhorev, V. Nujdin, V. Rastorguev, P. Sokolov
In the report features of formation of radar images (RI) and optical images (OI) in the mobile test complex of radio vision systems (RVS) of the car are presented. The radio vision system of the car (CRVS) of the MM-wavelength with frequency modulation is considered. Features of formation and processing of the radar-tracking image (RI) in CRVS are discussed, in particular: the sizes of the image, system of coordinates, primary and secondary processing of RI, requirements till speeds of transfer of figures, real time of processing, a subsystem of display of RI and synchronization. The structure of the mobile test complex of CRVS is described. This complex consists of: CRVS, a video-camera, the module of formation, record and display of RI and of optical images (OI), the module of control of a complex, the power supply unit. Features of formation and display OI are considered, in particular: the coordination of scale and a foreshortening of images, maintenance of time synchronization at display and records of OI, and questions of synchronous fusion of RI and OI also.
{"title":"Features of formation of radar-tracking and optical images in a mobile test complex of radiovision systems of the car","authors":"A. Ananenkov, A. Konovaltsev, A. Kukhorev, V. Nujdin, V. Rastorguev, P. Sokolov","doi":"10.1109/ICTONMW.2007.4446943","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446943","url":null,"abstract":"In the report features of formation of radar images (RI) and optical images (OI) in the mobile test complex of radio vision systems (RVS) of the car are presented. The radio vision system of the car (CRVS) of the MM-wavelength with frequency modulation is considered. Features of formation and processing of the radar-tracking image (RI) in CRVS are discussed, in particular: the sizes of the image, system of coordinates, primary and secondary processing of RI, requirements till speeds of transfer of figures, real time of processing, a subsystem of display of RI and synchronization. The structure of the mobile test complex of CRVS is described. This complex consists of: CRVS, a video-camera, the module of formation, record and display of RI and of optical images (OI), the module of control of a complex, the power supply unit. Features of formation and display OI are considered, in particular: the coordination of scale and a foreshortening of images, maintenance of time synchronization at display and records of OI, and questions of synchronous fusion of RI and OI also.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122814157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446931
Y. Khlifi, N. Boudriga
Optical label switching (OLS) has been proposed as a promising technology for providing resource provisioning and quality of service (QoS) support. Since TCP is (and may remain) the most popular protocol in the Internet, TCP implementation became a major issue in OLS network engineering. To take full advantage of OLS networks and integrate some TCP functions in the optical domain, the implementation of TCP over OLS is addressed to provide QoS control, resources provisioning and, finer granularity analysis. In this paper, we introduce a novel technique for packet retransmission based on the real-time management of TCP parameters, network resources, and traffic requirements. The technique handles activities such as signaling, switching, and contention resolution. Our approach is scalable packet retransmission and is based on buffering technique and contention resolution. It also provides a formal model to support QoS provision. Finally, simulation activity is performed in order to validate the proposed approach.
光标签交换(OLS)被认为是一种很有前途的技术，可以提供资源分配和服务质量(QoS)支持。由于TCP是(并且可能仍然是)Internet中最流行的协议，因此TCP的实现成为OLS网络工程中的一个主要问题。为了充分利用OLS网络的优势，并在光域中集成一些TCP功能，提出了TCP over OLS的实现，以提供QoS控制、资源配置和更细粒度的分析。本文介绍了一种基于TCP参数、网络资源和流量需求实时管理的数据包重传新技术。该技术处理信令、交换和争用解决等活动。我们的方法是可扩展的数据包重传，并基于缓冲技术和争用解决。它还提供了一个支持QoS提供的正式模型。最后，为了验证所提出的方法，进行了仿真活动。
{"title":"TCP over OLS networks: Real-time TCP management scheme for QoS provision","authors":"Y. Khlifi, N. Boudriga","doi":"10.1109/ICTONMW.2007.4446931","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446931","url":null,"abstract":"Optical label switching (OLS) has been proposed as a promising technology for providing resource provisioning and quality of service (QoS) support. Since TCP is (and may remain) the most popular protocol in the Internet, TCP implementation became a major issue in OLS network engineering. To take full advantage of OLS networks and integrate some TCP functions in the optical domain, the implementation of TCP over OLS is addressed to provide QoS control, resources provisioning and, finer granularity analysis. In this paper, we introduce a novel technique for packet retransmission based on the real-time management of TCP parameters, network resources, and traffic requirements. The technique handles activities such as signaling, switching, and contention resolution. Our approach is scalable packet retransmission and is based on buffering technique and contention resolution. It also provides a formal model to support QoS provision. Finally, simulation activity is performed in order to validate the proposed approach.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132934567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446968
O. Guellati, A. Fonseca, W. Bounour, M. Guerioune, Z. Mekhalif, J. Delhalle, A. Benaldija, J. Nagy
Carbon nanotubes "CNTs" have been the focus of numerous investigations because of their unique and superior properties that are a consequence of their particular structure. Their synthesis has been receiving much attention for a wide variety of applications. Though, scientists are researching more economic ways to produce these structures with high quality and purity, our aim in this research is to investigate and optimize the results of the CNTs growth process using CCVD technique. Due to its simplicity and low cost, this technique is perfectly suited for the production of nanomaterials for future industrial applications. MWNTs CCVD synthesis was carried out at 700degC in 5 to 120 minutes reaction. It is essentially based on 2 steps process: a catalyst impregnation preparation step followed by CCVD procedure using ethylene decomposition over Fe-Co/MgO support. During this synthesis, impurities were also produced. Thus, subsequent chemical purification steps were required to separate the tubes. Finally, characterization of crude and purified products was performed by TEM, SEM and FESEM focusing on composition, form and purity obtained.
{"title":"Carbon nanotube catalytic deposition synthesis","authors":"O. Guellati, A. Fonseca, W. Bounour, M. Guerioune, Z. Mekhalif, J. Delhalle, A. Benaldija, J. Nagy","doi":"10.1109/ICTONMW.2007.4446968","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446968","url":null,"abstract":"Carbon nanotubes \"CNTs\" have been the focus of numerous investigations because of their unique and superior properties that are a consequence of their particular structure. Their synthesis has been receiving much attention for a wide variety of applications. Though, scientists are researching more economic ways to produce these structures with high quality and purity, our aim in this research is to investigate and optimize the results of the CNTs growth process using CCVD technique. Due to its simplicity and low cost, this technique is perfectly suited for the production of nanomaterials for future industrial applications. MWNTs CCVD synthesis was carried out at 700degC in 5 to 120 minutes reaction. It is essentially based on 2 steps process: a catalyst impregnation preparation step followed by CCVD procedure using ethylene decomposition over Fe-Co/MgO support. During this synthesis, impurities were also produced. Thus, subsequent chemical purification steps were required to separate the tubes. Finally, characterization of crude and purified products was performed by TEM, SEM and FESEM focusing on composition, form and purity obtained.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131645858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446946
M. M. Karkhanehchi, H. Sariri
We investigate the effect of ASE on the gain modulation, referred to also as overmodulation. The gain modulation is the low-frequency ( kHz) amplitude modulation of the EDFA pump and the communication signal used for propagating line monitoring information. We develop the model of Novak and Moesle (2002), by including amplified spontaneous emission (ASE), that they neglected it. The derivation of an analytical model for EDFA overmodulation response has been presented. This model provide analytical expressions for the pump and input signal overmodulation responses, respectively. These expressions describe the output signal modulation index amplitude and phase, assuming small sinusoidal steady-state oscillations of the mean pump or input signal power. In this paper we show that ASE have some effect on predictions in the high gain/low saturation regime.
{"title":"Effect of ASE on the gain modulation in EDFAs","authors":"M. M. Karkhanehchi, H. Sariri","doi":"10.1109/ICTONMW.2007.4446946","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446946","url":null,"abstract":"We investigate the effect of ASE on the gain modulation, referred to also as overmodulation. The gain modulation is the low-frequency ( kHz) amplitude modulation of the EDFA pump and the communication signal used for propagating line monitoring information. We develop the model of Novak and Moesle (2002), by including amplified spontaneous emission (ASE), that they neglected it. The derivation of an analytical model for EDFA overmodulation response has been presented. This model provide analytical expressions for the pump and input signal overmodulation responses, respectively. These expressions describe the output signal modulation index amplitude and phase, assuming small sinusoidal steady-state oscillations of the mean pump or input signal power. In this paper we show that ASE have some effect on predictions in the high gain/low saturation regime.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123481536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446907
A. Toguyéni, O. Korbaa
These ten last years, the emergences of new applications through Internet such as multimedia applications (VoIP, video broadcasting ...) or networked control application, users need more and more quality of service (QoS) when using Internet. However, the requested QoS is not the same depending on the application. Some of them request a lot of bandwidth like video broadcasting others need short guaranteed delays. Several new models to manage internet traffic have been proposed. Most of them focus on specific QoS criteria that they want to optimize. This paper focus on approaches based on MPLS that are more adapted to the configuration of ISP networks. The paper first introduces the different mechanisms that can be used to improve the QoS of a network such as the models of traffic classification (IntServ or DiffServ) or multipath routing. It also justifies the choice of MPLS technology versus a simple use of IP. After that, the paper presents main MPLS approaches such as MATE, LDM or LBWDP that try to guaranty a certain quality with respect to specific criteria. In the last part, it presents new models such as PEMS that try to adapt the offered quality depending on the class of the routed traffic.
{"title":"Quality of service of internet service provider networks: State of the art and new trends","authors":"A. Toguyéni, O. Korbaa","doi":"10.1109/ICTONMW.2007.4446907","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446907","url":null,"abstract":"These ten last years, the emergences of new applications through Internet such as multimedia applications (VoIP, video broadcasting ...) or networked control application, users need more and more quality of service (QoS) when using Internet. However, the requested QoS is not the same depending on the application. Some of them request a lot of bandwidth like video broadcasting others need short guaranteed delays. Several new models to manage internet traffic have been proposed. Most of them focus on specific QoS criteria that they want to optimize. This paper focus on approaches based on MPLS that are more adapted to the configuration of ISP networks. The paper first introduces the different mechanisms that can be used to improve the QoS of a network such as the models of traffic classification (IntServ or DiffServ) or multipath routing. It also justifies the choice of MPLS technology versus a simple use of IP. After that, the paper presents main MPLS approaches such as MATE, LDM or LBWDP that try to guaranty a certain quality with respect to specific criteria. In the last part, it presents new models such as PEMS that try to adapt the offered quality depending on the class of the routed traffic.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114383027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446974
G. Budzyń, G. Dudzik, J. Rzepka
Techniques of frequency stabilization of the single mode 780 nm VCSEL laser with the use of an external 85Rb rubidium cell are presented. There is presented a comparison of different active and passive stabilization methods. The best method, using Zeeman splitting phenomenon and an optical switch with SSFLC cell, allowed to achieve stability level of 3ldr10-8 which responds to frequency variations of only 10 MHz. The stabilized VCSEL laser could be used as the source of radiation in an optical communication and in a laser interferometry. The same technique with different cells (for example cesium cell) could be used for stabilization of another wavelength of laser radiation used in optical networks.
{"title":"Frequency stabilization of a single mode 780nm VCSEL lasers with the use of a rubidium cell","authors":"G. Budzyń, G. Dudzik, J. Rzepka","doi":"10.1109/ICTONMW.2007.4446974","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446974","url":null,"abstract":"Techniques of frequency stabilization of the single mode 780 nm VCSEL laser with the use of an external 85Rb rubidium cell are presented. There is presented a comparison of different active and passive stabilization methods. The best method, using Zeeman splitting phenomenon and an optical switch with SSFLC cell, allowed to achieve stability level of 3ldr10-8 which responds to frequency variations of only 10 MHz. The stabilized VCSEL laser could be used as the source of radiation in an optical communication and in a laser interferometry. The same technique with different cells (for example cesium cell) could be used for stabilization of another wavelength of laser radiation used in optical networks.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126627225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-01DOI: 10.1109/ICTONMW.2007.4446972
A. Missaoui, L. Beji, M. Gaidi, A. Bouazizi
We present the optical properties of sulphide cadmium (CdS) deposited, by vacuum evaporation technique, on porous p-type GaAs substrates with different porosities and compared to that deposited on glass and nominal p-type GaAs substrates. The CdS layer deposited on glass substrate exhibit average transmittance about 62% in the visible region and very sharp absorption edge at 495 nm. The room temperature band gap energy calculated from the transmittance spectra is about 2.5 eV. The surface roughness (rms) has been determined by atomic force microscopy (AFM). The photoluminescence (PL) and reflectance spectroscopy of the samples before and after deposition of CdS were measured to study the effect of the porosity on the luminescence properties of CdS/porous GaAs heterostructures.
{"title":"Study of band-edge emission in CdS layers grown on |p-type porous GaAs substrates","authors":"A. Missaoui, L. Beji, M. Gaidi, A. Bouazizi","doi":"10.1109/ICTONMW.2007.4446972","DOIUrl":"https://doi.org/10.1109/ICTONMW.2007.4446972","url":null,"abstract":"We present the optical properties of sulphide cadmium (CdS) deposited, by vacuum evaporation technique, on porous p-type GaAs substrates with different porosities and compared to that deposited on glass and nominal p-type GaAs substrates. The CdS layer deposited on glass substrate exhibit average transmittance about 62% in the visible region and very sharp absorption edge at 495 nm. The room temperature band gap energy calculated from the transmittance spectra is about 2.5 eV. The surface roughness (rms) has been determined by atomic force microscopy (AFM). The photoluminescence (PL) and reflectance spectroscopy of the samples before and after deposition of CdS were measured to study the effect of the porosity on the luminescence properties of CdS/porous GaAs heterostructures.","PeriodicalId":366170,"journal":{"name":"2007 ICTON Mediterranean Winter Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127955790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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