Pub Date : 2012-08-31DOI: 10.5923/J.IJOE.20110101.01
Ahmed Nabih, Z. Rashed
In the present paper, we have deeply investigated the transmission efficiency degradation of electrooptic modulator devices in thermal irradiated hard environments over wide range of the operating parameters. It is well known that the radiation-induced electrooptic modulator defects can modify the initial doping concentrations, creating generation-recombination centres and introducing trapping of carriers. Additionally, rate of the lattice defects is thermally activated and reduces for increasing irradiation temperature as a result of annealing of the damage. Both the ambient temperature and the irradiation dose possess sever effects on the electro-optical characteristics and consequently the performance characteristics of electroptic modulator devices. As well as we have deeply developed the modelling basics of electrooptic modulator devices, which may be used to analyzed the modulator quantum efficiency, dark current, modulating voltage, modulating frequency, 3-dB bandwidth, transmitted signal bandwidth, modulator quality factor, modulator sensitivity, modulator sensitivity bandwidth product, switching voltage, modulator device performance index, operating switching time and speed response of these irradiated electrooptic modulator devices after different irradiation fluences.
{"title":"Speed Performance Degradation of Electrooptic Modulator Devices by Neutrons Irradiations at High temperature Effects","authors":"Ahmed Nabih, Z. Rashed","doi":"10.5923/J.IJOE.20110101.01","DOIUrl":"https://doi.org/10.5923/J.IJOE.20110101.01","url":null,"abstract":"In the present paper, we have deeply investigated the transmission efficiency degradation of electrooptic modulator devices in thermal irradiated hard environments over wide range of the operating parameters. It is well known that the radiation-induced electrooptic modulator defects can modify the initial doping concentrations, creating generation-recombination centres and introducing trapping of carriers. Additionally, rate of the lattice defects is thermally activated and reduces for increasing irradiation temperature as a result of annealing of the damage. Both the ambient temperature and the irradiation dose possess sever effects on the electro-optical characteristics and consequently the performance characteristics of electroptic modulator devices. As well as we have deeply developed the modelling basics of electrooptic modulator devices, which may be used to analyzed the modulator quantum efficiency, dark current, modulating voltage, modulating frequency, 3-dB bandwidth, transmitted signal bandwidth, modulator quality factor, modulator sensitivity, modulator sensitivity bandwidth product, switching voltage, modulator device performance index, operating switching time and speed response of these irradiated electrooptic modulator devices after different irradiation fluences.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"19 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88327383","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 : 2012-08-31DOI: 10.5923/J.IJOE.20120203.01
L. A. Faria, L. Nohra, N. Gomes, F. Alves
Nowadays, the detection in the infrared band (IR) has shown great importance in several areas such as skin illnesses detection, remote sensor and in different military devices. The responsible for such detection is, basically, photodetector arrays (FPA) sensitive to infrared radiation. This paper presents a modular and adaptative test-bed, based upon an arrangement of 24 electro and optical components divided in four major functional blocks, providing methodological procedures that allows an accurate design verification of infra-red photodetectors. The target metric that the system is con- ceived to provide is Responsivity. In essence, the developed system differs from the previous ones by its adaptability and its hardware modularity conception that allows an easy reconfiguration to test different kinds of photodetectors. Here we compare a theoretical calculation of responsivity with actual experimental measurements, allowing low temperature meas- urements between 16K and 100K, in wavelength from 0.7μm up to 12μm (0.8μm to 1.0μm in this work) and the possibility to set detectors with up to 10 I/O electric terminals. The operational validation of this test-bed is achieved with a studied Quantum Well Infrared Photodetectors (QWIP), exhibiting high compliance with the expected theoretical results.
{"title":"A high-performance Test-Bed Dedicated for Responsivity Measurements of Infrared Photodetectors in a Wide Band of Low Temperatures","authors":"L. A. Faria, L. Nohra, N. Gomes, F. Alves","doi":"10.5923/J.IJOE.20120203.01","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120203.01","url":null,"abstract":"Nowadays, the detection in the infrared band (IR) has shown great importance in several areas such as skin illnesses detection, remote sensor and in different military devices. The responsible for such detection is, basically, photodetector arrays (FPA) sensitive to infrared radiation. This paper presents a modular and adaptative test-bed, based upon an arrangement of 24 electro and optical components divided in four major functional blocks, providing methodological procedures that allows an accurate design verification of infra-red photodetectors. The target metric that the system is con- ceived to provide is Responsivity. In essence, the developed system differs from the previous ones by its adaptability and its hardware modularity conception that allows an easy reconfiguration to test different kinds of photodetectors. Here we compare a theoretical calculation of responsivity with actual experimental measurements, allowing low temperature meas- urements between 16K and 100K, in wavelength from 0.7μm up to 12μm (0.8μm to 1.0μm in this work) and the possibility to set detectors with up to 10 I/O electric terminals. The operational validation of this test-bed is achieved with a studied Quantum Well Infrared Photodetectors (QWIP), exhibiting high compliance with the expected theoretical results.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"9 1","pages":"12-17"},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87360494","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 : 2012-08-31DOI: 10.5923/J.IJOE.20120202.02
Y. Arafat, F. M. Mohammedy, M. Hassan
In this paper, various methods for characterization of semiconductor charge carrier lifetime are reviewed and an optical technique is described in detail. This technique is contactless, all-optical and based upon measurements of free carrier absorption transients by an infrared probe beam following electron-hole pair excitation by a pulsed laser beam. Main features are a direct probing of the excess carrier density coupled with a homogeneous carrier distribution within the sample, enabling precision studies of different recombination mechanisms. The method is capable of measuring the lifetime over a broad range of injections (10 13 -10 18 cm -3 ) probing the minority carrier lifetime, the high injection lifetime and Auger recombination, as well as the transition between these ranges. Performance and limitations of the technique, such as lateral resolution, are addressed while application of the technique for lifetime mapping and effects of surface recombination are also outlined. Results from detailed studies of the injection dependence yield good agreement with the Shockley-Read-Hall theory, whereas the coefficient for Auger recombination shows an apparent shift to a higher value, with respect to the traditionally accepted value, at carrier densities below 2×10 17 cm -3 . Data also indicate an increased value of the coefficient for bimolecular recombination from the generally accepted value. Measurement on an electron irradiated wafer and wafers of exceptionally high carrier lifetimes are also discussed within the framework of different recombination mechanisms.
本文综述了表征半导体载流子寿命的各种方法，并详细介绍了一种光学技术。该技术是一种非接触式的全光学技术，基于脉冲激光束激发电子-空穴对后红外探针束对自由载流子吸收瞬态的测量。主要特点是直接探测过量载流子密度，以及样品内均匀的载流子分布，从而能够精确研究不同的重组机制。该方法能够在宽注入范围内(10 13 -10 18 cm -3)测量寿命，探测少量载流子寿命、高注入寿命和俄歇复合，以及这些范围之间的过渡。讨论了该技术的性能和局限性，例如横向分辨率，同时概述了该技术在生命周期测绘和表面重组效果方面的应用。对注入依赖性的详细研究结果与Shockley-Read-Hall理论很好地吻合，而在载流子密度低于2×10 17 cm -3时，俄歇复合系数与传统接受的值相比，明显转向更高的值。数据还表明，双分子重组系数的值比普遍接受的值有所增加。在不同的复合机制框架下，还讨论了电子辐照晶圆和超长载流子寿命晶圆的测量。
{"title":"Optical and Other Measurement Techniques of Carrier Lifetime in Semiconductors","authors":"Y. Arafat, F. M. Mohammedy, M. Hassan","doi":"10.5923/J.IJOE.20120202.02","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120202.02","url":null,"abstract":"In this paper, various methods for characterization of semiconductor charge carrier lifetime are reviewed and an optical technique is described in detail. This technique is contactless, all-optical and based upon measurements of free carrier absorption transients by an infrared probe beam following electron-hole pair excitation by a pulsed laser beam. Main features are a direct probing of the excess carrier density coupled with a homogeneous carrier distribution within the sample, enabling precision studies of different recombination mechanisms. The method is capable of measuring the lifetime over a broad range of injections (10 13 -10 18 cm -3 ) probing the minority carrier lifetime, the high injection lifetime and Auger recombination, as well as the transition between these ranges. Performance and limitations of the technique, such as lateral resolution, are addressed while application of the technique for lifetime mapping and effects of surface recombination are also outlined. Results from detailed studies of the injection dependence yield good agreement with the Shockley-Read-Hall theory, whereas the coefficient for Auger recombination shows an apparent shift to a higher value, with respect to the traditionally accepted value, at carrier densities below 2×10 17 cm -3 . Data also indicate an increased value of the coefficient for bimolecular recombination from the generally accepted value. Measurement on an electron irradiated wafer and wafers of exceptionally high carrier lifetimes are also discussed within the framework of different recombination mechanisms.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"19 1","pages":"5-11"},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83521763","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 : 2012-08-31DOI: 10.5923/J.IJOE.20110101.02
S. Sahu, R. Pal, Shantanu Dhar
Non-linear material based all-optical switching mechanism is utilized here to implement the all-optical paral- lel subtraction scheme. Optical tree architectures here convert analog optical signal to the corresponding digital one. A two bit all-optical binary parallel subtractor has been proposed and which may be elevated to a higher bit parallel subtractor in course using all-optical half-subtractor and a full-subtractor. These are constructed by a composite slab of linear medium (LM) and non-linear medium (NLM) and it is the building block of our proposed subtructor circuit. These circuits are all-optical and fully parallel in nature. It can also gear up to the highest ability of optical performance in high-speed all-optical computing system.
{"title":"Nonlinear Material Based All-Optical Parallel Subtraction Scheme: an Implementation","authors":"S. Sahu, R. Pal, Shantanu Dhar","doi":"10.5923/J.IJOE.20110101.02","DOIUrl":"https://doi.org/10.5923/J.IJOE.20110101.02","url":null,"abstract":"Non-linear material based all-optical switching mechanism is utilized here to implement the all-optical paral- lel subtraction scheme. Optical tree architectures here convert analog optical signal to the corresponding digital one. A two bit all-optical binary parallel subtractor has been proposed and which may be elevated to a higher bit parallel subtractor in course using all-optical half-subtractor and a full-subtractor. These are constructed by a composite slab of linear medium (LM) and non-linear medium (NLM) and it is the building block of our proposed subtructor circuit. These circuits are all-optical and fully parallel in nature. It can also gear up to the highest ability of optical performance in high-speed all-optical computing system.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"199 1","pages":"7-11"},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76162723","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 : 2012-08-31DOI: 10.5923/J.IJOE.20120202.01
K. Nagamani, V. Reddy, Y. Lingappa, K. Reddy, R. Miles
In recent years, zinc cadmium sulphide (ZnxCd1-xS) alloy compounds have paid much attention in the fields of opto-electronics, particularly in photovoltaic devices because of its tunable energy gap and the lattice parameters. The energy band gap of ZnxCd1-xS is controlled by the change of Zn-composition in order to suit the material properties with that of absorber material in solar cells. In this paper, we report on the effect of Zn-composition on physical properties of ZnxCd1-xS thin films deposited on corning glass substrates by solution growth method. The layers were prepared for different 'x' values that vary in the range, 0 - 1.0 at. %. The as-grown layers were characterized using EDAX, XRD, SEM, and UV-Vis-NIR spectrophotometers. All the layers showed a strong (002) plane as the preferred orientation that exhibited the hexagonal crystal structure. The composition of the layers agrees approximately with that of the elements in the solution. The films showed an average optical transmittance of 72 % at a zinc composition of 0.75 with a band gap of 3.88 eV.
{"title":"Physical Properties of Zn x Cd 1-x S Nanocrytalline Layers Synthesized by Solution Growth Method","authors":"K. Nagamani, V. Reddy, Y. Lingappa, K. Reddy, R. Miles","doi":"10.5923/J.IJOE.20120202.01","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120202.01","url":null,"abstract":"In recent years, zinc cadmium sulphide (ZnxCd1-xS) alloy compounds have paid much attention in the fields of opto-electronics, particularly in photovoltaic devices because of its tunable energy gap and the lattice parameters. The energy band gap of ZnxCd1-xS is controlled by the change of Zn-composition in order to suit the material properties with that of absorber material in solar cells. In this paper, we report on the effect of Zn-composition on physical properties of ZnxCd1-xS thin films deposited on corning glass substrates by solution growth method. The layers were prepared for different 'x' values that vary in the range, 0 - 1.0 at. %. The as-grown layers were characterized using EDAX, XRD, SEM, and UV-Vis-NIR spectrophotometers. All the layers showed a strong (002) plane as the preferred orientation that exhibited the hexagonal crystal structure. The composition of the layers agrees approximately with that of the elements in the solution. The films showed an average optical transmittance of 72 % at a zinc composition of 0.75 with a band gap of 3.88 eV.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"24 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80807058","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 : 2012-08-09DOI: 10.5923/J.IJOE.20120204.01
T. Lotz, W. Sauer-Greff, R. Urbansky
Achieving high spectral efficiency in optical transmissions has recently attracted much attention, aiming to satisfy the ever increasing demand for high data rates in optical fiber communications. Therefore, strong Forward Error Correction (FEC) coding in combination with multilevel modulation schemes is mandatory to approach the channel capacity of the transmission link. In this paper we give design rules on the joint optimization of coding and signal constellations under practical considerations. We give trade-offs between spectral efficiency and hardware complexity, by comparing coding schemes using capacity achieving constellations with bit-interleaved coded modulation and iterative decoding (BICM-ID) against applying conventional square quadrature amplitude modulation (QAM) constellations but employing powerful low complexity low-density parity-check (LDPC) codes. Both schemes are suitable for optical single carrier (SC) and optical orthogonal frequency-division multiplexing (OFDM) transmission systems, where we consider the latter one in this paper, due to well-studied equalization techniques in wireless communications. We numerically study the performance of different coded modulation formats in optical OFDM transmission, showing that for a fiber optical transmission link of 960 km reach the net spectral efficiency can be increased by ≈0.4 bit/s/Hz to 8.61 bit/s/Hz at a post FEC BER of <10-15 by using coded optimized constellations instead of coded 64-QAM.In this paper we propose a high spectral efficient coded modulation scheme for implementation in future optical communication systems operating at data rates beyond 400 Gb/s. In detail, we adapt the “Turbo Principle” to BICM-ID[8] and combine it with a high-rate outer algebraic code to obtain a post-FEC BER <10-15, which is a typical demand in optical transponders. Furthermore we give simple design principles for the design of BICM-ID based on the extrinsic information transfer (EXIT) chart analysis[9]. The optical channel is considered to be weakly-nonlinear. Therefore the proposed techniques are also applicable for single-carrier transmission; however we consider OFDM since it appears to be more appropriate for the high order modulation formats and efficient equalization algorithms that are well established in wireless communications.
为了满足日益增长的光纤通信对高数据速率的需求，在光传输中实现高频谱效率是近年来备受关注的问题。因此，强前向纠错(FEC)编码与多电平调制方案相结合是必要的，以接近传输链路的信道容量。本文从实际考虑出发，给出了编码与信号星座联合优化的设计原则。我们给出了频谱效率和硬件复杂性之间的权衡，通过比较使用比特交错编码调制和迭代解码(BICM-ID)的容量实现星座的编码方案与使用传统的方形正交调幅(QAM)星座但使用强大的低复杂度低密度奇偶校验(LDPC)代码的编码方案。这两种方案都适用于光单载波(SC)和光正交频分复用(OFDM)传输系统，由于无线通信中的均衡技术得到了充分的研究，本文将考虑后一种方案。数值研究了不同编码调制格式在光OFDM传输中的性能，结果表明，在960 km的光纤传输链路上，在FEC后误码率<10-15的情况下，采用编码优化星座代替编码64-QAM，净频谱效率可提高约0.4 bit/s/Hz至8.61 bit/s/Hz。在本文中，我们提出了一个高频谱效率的编码调制方案，以实现未来的光通信系统在数据速率超过400gb /s。具体而言，我们将“Turbo原理”应用于BICM-ID[8]，并将其与高速率外代数码相结合，获得fec后的BER <10-15，这是光转发器的典型需求。此外，我们给出了基于外在信息传递(extrinsic information transfer, EXIT)图分析的BICM-ID设计的简单设计原则[9]。光通道被认为是弱非线性的。因此，所提出的技术也适用于单载波传输;然而，我们考虑OFDM，因为它似乎更适合无线通信中建立的高阶调制格式和有效的均衡算法。
{"title":"Spectral Efficient Coding Schemes in Optical Communications","authors":"T. Lotz, W. Sauer-Greff, R. Urbansky","doi":"10.5923/J.IJOE.20120204.01","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120204.01","url":null,"abstract":"Achieving high spectral efficiency in optical transmissions has recently attracted much attention, aiming to satisfy the ever increasing demand for high data rates in optical fiber communications. Therefore, strong Forward Error Correction (FEC) coding in combination with multilevel modulation schemes is mandatory to approach the channel capacity of the transmission link. In this paper we give design rules on the joint optimization of coding and signal constellations under practical considerations. We give trade-offs between spectral efficiency and hardware complexity, by comparing coding schemes using capacity achieving constellations with bit-interleaved coded modulation and iterative decoding (BICM-ID) against applying conventional square quadrature amplitude modulation (QAM) constellations but employing powerful low complexity low-density parity-check (LDPC) codes. Both schemes are suitable for optical single carrier (SC) and optical orthogonal frequency-division multiplexing (OFDM) transmission systems, where we consider the latter one in this paper, due to well-studied equalization techniques in wireless communications. We numerically study the performance of different coded modulation formats in optical OFDM transmission, showing that for a fiber optical transmission link of 960 km reach the net spectral efficiency can be increased by ≈0.4 bit/s/Hz to 8.61 bit/s/Hz at a post FEC BER of <10-15 by using coded optimized constellations instead of coded 64-QAM.In this paper we propose a high spectral efficient coded modulation scheme for implementation in future optical communication systems operating at data rates beyond 400 Gb/s. In detail, we adapt the “Turbo Principle” to BICM-ID[8] and combine it with a high-rate outer algebraic code to obtain a post-FEC BER <10-15, which is a typical demand in optical transponders. Furthermore we give simple design principles for the design of BICM-ID based on the extrinsic information transfer (EXIT) chart analysis[9]. The optical channel is considered to be weakly-nonlinear. Therefore the proposed techniques are also applicable for single-carrier transmission; however we consider OFDM since it appears to be more appropriate for the high order modulation formats and efficient equalization algorithms that are well established in wireless communications.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"33 1","pages":"18-25"},"PeriodicalIF":0.0,"publicationDate":"2012-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82886323","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 : 2012-02-01DOI: 10.5923/J.IJOE.20120201.02
P. Kishore, D. Dinakar, M. S. Shankar, K. Srimannarayana, P. V. Rao, D. Sengupta
A non-contact vibration sensor is demonstrated using bifurcated bundle fiber based on the principle of extrinsic reflective intensity modulation for monitoring the health condition of the diesel engine. An IR-source is used along with glass fibers to avoid the effect of stray light in sensing. The encapsulation of the sensor enables easy alignment, flexible handling and usage in harsh environments. The sensor is capable of measuring the frequencies up to 650Hz with vibration amplitude resolution of 10µm, enough to monitor the vibrations generated in heavy machines like diesel engine.
{"title":"Non-Contact Vibration Sensor Using Bifurcated Bundle Fiber for Real Time Monitoring of Diesel Engine","authors":"P. Kishore, D. Dinakar, M. S. Shankar, K. Srimannarayana, P. V. Rao, D. Sengupta","doi":"10.5923/J.IJOE.20120201.02","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120201.02","url":null,"abstract":"A non-contact vibration sensor is demonstrated using bifurcated bundle fiber based on the principle of extrinsic reflective intensity modulation for monitoring the health condition of the diesel engine. An IR-source is used along with glass fibers to avoid the effect of stray light in sensing. The encapsulation of the sensor enables easy alignment, flexible handling and usage in harsh environments. The sensor is capable of measuring the frequencies up to 650Hz with vibration amplitude resolution of 10µm, enough to monitor the vibrations generated in heavy machines like diesel engine.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"484 1","pages":"4-9"},"PeriodicalIF":0.0,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86767219","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 : 2012-02-01DOI: 10.5923/J.IJOE.20120201.04
M. Nahas
In this paper, we present 50 GHz spaced 25 × 40 Gbit/s WDM transmission over 560 km using SMF-based Large Effective Area Fiber (LEAF) in a recirculating loop. The paper uses band-limited RZ signals carrying 2 31 -1 PRBS data, and shows that transmission distance of 560 km can be achieved with BER ≤ 10 -9 using 1 mW peak power and 4 ps pulse-width for each data signal. To attain this, optical filters with sharp transmission characteristics are used in both transmitter and receiver. The results demonstrated in this paper are based on simulation, and the author believes that the propagation distance reached in the paper is the longest distance achieved for such system
{"title":"50 GHz Spaced 25 × 40 Gbit/s WDM Transmission Over 560 km Using SMF-Based Large Effective Area Fiber (LEAF)","authors":"M. Nahas","doi":"10.5923/J.IJOE.20120201.04","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120201.04","url":null,"abstract":"In this paper, we present 50 GHz spaced 25 × 40 Gbit/s WDM transmission over 560 km using SMF-based Large Effective Area Fiber (LEAF) in a recirculating loop. The paper uses band-limited RZ signals carrying 2 31 -1 PRBS data, and shows that transmission distance of 560 km can be achieved with BER ≤ 10 -9 using 1 mW peak power and 4 ps pulse-width for each data signal. To attain this, optical filters with sharp transmission characteristics are used in both transmitter and receiver. The results demonstrated in this paper are based on simulation, and the author believes that the propagation distance reached in the paper is the longest distance achieved for such system","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"33 6 1","pages":"17-20"},"PeriodicalIF":0.0,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82774132","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 : 2012-02-01DOI: 10.5923/J.IJOE.20120201.03
I. Iliev, S. Gocheva-Ilieva, K. Temelkov, N. Vuchkov, N. Sabotinov
The subject of investigation is a SrBr2 laser generating at a wavelength λ = 6.45 µm. This type of laser gen- eration is finding ever wider application in medicine when working with soft and bone tissue providing rapid subsequent recovery. Of all laser sources generating at this wavelength, the new SrBr2 laser is gaining ever more ground due to its ad- vantages and is therefore of commercial interest. With the goal of developing new, higher-powered SrBr2 lasers, in this paper, the so-called phenomenological modeling has been used for the first time for this type of laser. An estimation of the degree of influence of 7 independent input laser quantities on laser output power has been performed using factor and regression analysis. A methodology has been developed with the help of which a series of new SrBr2 lasers with higher output power than existing ones has been predicted. Problems related to the planning of the experiment have been partially solved - car- rying out of filtering and extremal experiment.
{"title":"Multivariate Statistical Analysis in Planning Experiments for a New Strontium Bromide Vapour Laser","authors":"I. Iliev, S. Gocheva-Ilieva, K. Temelkov, N. Vuchkov, N. Sabotinov","doi":"10.5923/J.IJOE.20120201.03","DOIUrl":"https://doi.org/10.5923/J.IJOE.20120201.03","url":null,"abstract":"The subject of investigation is a SrBr2 laser generating at a wavelength λ = 6.45 µm. This type of laser gen- eration is finding ever wider application in medicine when working with soft and bone tissue providing rapid subsequent recovery. Of all laser sources generating at this wavelength, the new SrBr2 laser is gaining ever more ground due to its ad- vantages and is therefore of commercial interest. With the goal of developing new, higher-powered SrBr2 lasers, in this paper, the so-called phenomenological modeling has been used for the first time for this type of laser. An estimation of the degree of influence of 7 independent input laser quantities on laser output power has been performed using factor and regression analysis. A methodology has been developed with the help of which a series of new SrBr2 lasers with higher output power than existing ones has been predicted. Problems related to the planning of the experiment have been partially solved - car- rying out of filtering and extremal experiment.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"68 1","pages":"10-16"},"PeriodicalIF":0.0,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79505419","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 : 2012-02-01DOI: 10.5923/j.ijoe.20120201.01
M. Hamada, E. Gomaa, N. A. El-Shishtawi
The optical and mechanical properties of 10% by weight for PVA (Polyvinyl alcohol) in presence of different CoCl2 concentrations in absence and presence of 44 % by weight ethanol - water solvents were estimated at 298.15 K. The evaluated optical parameters like molar refraction (RM),specific refractivity(e) and molecular polarizability (α) were com- pared and discussed with that of mechanical tension parameters like elastic modulus and Shear modulus.
{"title":"Optomechanical Properties of 10% PVA (Polyvinylalcohol) in Presence of CoCl 2 and 44% Ethanol Water Compositions","authors":"M. Hamada, E. Gomaa, N. A. El-Shishtawi","doi":"10.5923/j.ijoe.20120201.01","DOIUrl":"https://doi.org/10.5923/j.ijoe.20120201.01","url":null,"abstract":"The optical and mechanical properties of 10% by weight for PVA (Polyvinyl alcohol) in presence of different CoCl2 concentrations in absence and presence of 44 % by weight ethanol - water solvents were estimated at 298.15 K. The evaluated optical parameters like molar refraction (RM),specific refractivity(e) and molecular polarizability (α) were com- pared and discussed with that of mechanical tension parameters like elastic modulus and Shear modulus.","PeriodicalId":14375,"journal":{"name":"International Journal of Online Engineering","volume":"71 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82464382","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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