Pub Date : 2002-08-07DOI: 10.1109/PAIA.2002.995079
E. El-Badawy, F. El-Halafawy, A.E.-N.A. Mohammed, M. Aly
In the present, paper, both self-trapping (paraxial propagation) and thermal effects (caustic zones and maximum axial temperature) in W-shaped refractive index fibers are parametrically investigated to minimize the thermal effects and to maximize the self-trapping. Ray optics is employed with a closed form solution for the ray trajectory. Conditions for maximum self-trapping are parametrically investigated. A figure of merit is designed and tested good performance.
{"title":"Optmization of self-trapping and thermal effects in W-shaped optical fibers","authors":"E. El-Badawy, F. El-Halafawy, A.E.-N.A. Mohammed, M. Aly","doi":"10.1109/PAIA.2002.995079","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995079","url":null,"abstract":"In the present, paper, both self-trapping (paraxial propagation) and thermal effects (caustic zones and maximum axial temperature) in W-shaped refractive index fibers are parametrically investigated to minimize the thermal effects and to maximize the self-trapping. Ray optics is employed with a closed form solution for the ray trajectory. Conditions for maximum self-trapping are parametrically investigated. A figure of merit is designed and tested good performance.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122442866","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995076
S. Abdallah, B. Saleh, A. Aboulsoud
There is a trend to replace thin film by electronic solid state image sensors in many applications due to their outstanding performance and abilities in new fields of image capture applications such as digital still photography, video communications, as video conferencing cameras, and video phone. In addition to digital radiography, as medical radiography in which X-ray films are replaced. The results were superior. There is no need for film processing. It gives better resolution and the image can be restored digitally. The imaging system includes some essential and common elements, such as an imaging lens, an image sensor, and a light source. The scope of this paper is to concentrate on two main types of image sensor elements, namely the CCD and the CMOS.
{"title":"A general overview of solid state imaging sensors types","authors":"S. Abdallah, B. Saleh, A. Aboulsoud","doi":"10.1109/PAIA.2002.995076","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995076","url":null,"abstract":"There is a trend to replace thin film by electronic solid state image sensors in many applications due to their outstanding performance and abilities in new fields of image capture applications such as digital still photography, video communications, as video conferencing cameras, and video phone. In addition to digital radiography, as medical radiography in which X-ray films are replaced. The results were superior. There is no need for film processing. It gives better resolution and the image can be restored digitally. The imaging system includes some essential and common elements, such as an imaging lens, an image sensor, and a light source. The scope of this paper is to concentrate on two main types of image sensor elements, namely the CCD and the CMOS.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114411040","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995077
F. El-Halafawy, A. Aboul-Enein, A.E.-N.A. Mohammed, M.M. El-Khamry
In the present paper, an integrated study of the nonlinear response of optical wide area networks has been carried out. The linear refractive index, the spectral losses, and the nonlinear refractive index coefficient of the germania doped silica [SiO/sub 2/(1-x)+GeO/sub 2/(x)] are considered. Also, the gain of the employed erbium-doped fiber amplifier is both thermally and spectrally dependent variable. Two propagation techniques are employed to investigate the transmitted bit rate: namely soliton and maximum time division techniques. High-order mode fibers are employed to achieve chromatic dispersion management where high bit rates are assured. The investigation of the nonlinear response is based on a very important criteria: namely the product of the bit rate and the repeater spacing. Such product is linearity and is positively correlated with a newly integrated figure of merit.
{"title":"Nonlinear integrated response of optical wide area networks (OWANs)","authors":"F. El-Halafawy, A. Aboul-Enein, A.E.-N.A. Mohammed, M.M. El-Khamry","doi":"10.1109/PAIA.2002.995077","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995077","url":null,"abstract":"In the present paper, an integrated study of the nonlinear response of optical wide area networks has been carried out. The linear refractive index, the spectral losses, and the nonlinear refractive index coefficient of the germania doped silica [SiO/sub 2/(1-x)+GeO/sub 2/(x)] are considered. Also, the gain of the employed erbium-doped fiber amplifier is both thermally and spectrally dependent variable. Two propagation techniques are employed to investigate the transmitted bit rate: namely soliton and maximum time division techniques. High-order mode fibers are employed to achieve chromatic dispersion management where high bit rates are assured. The investigation of the nonlinear response is based on a very important criteria: namely the product of the bit rate and the repeater spacing. Such product is linearity and is positively correlated with a newly integrated figure of merit.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134525893","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995083
D. Khalil, A. H. Morshed
In this work we present a locally developed MEMS-based technology for the assembly and characterization of optical MEMS components. For the assembly purpose, the processes required for the Si and glass micromachining (oxidation, photolithography and wet etching) are developed in the Laser lab at the faculty of Engineering, Ain Shams University. For the characterization purpose, an automated set-up for the spot size and misalignment loss measurements are developed.
{"title":"Assembly and characterization of optical MEMS (micro-electro-mechanical systems)","authors":"D. Khalil, A. H. Morshed","doi":"10.1109/PAIA.2002.995083","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995083","url":null,"abstract":"In this work we present a locally developed MEMS-based technology for the assembly and characterization of optical MEMS components. For the assembly purpose, the processes required for the Si and glass micromachining (oxidation, photolithography and wet etching) are developed in the Laser lab at the faculty of Engineering, Ain Shams University. For the characterization purpose, an automated set-up for the spot size and misalignment loss measurements are developed.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115108131","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995081
A. Sattar, I. Azzouz, Mahmoud Shafik, Y. Badr
Two different host glasses for Er/sup 3+/, namely, phosphate and borate glasses were prepared. Yb/sup 3+/ was added as a sensitizer to investigate its effect on the absorption, emission, gain cross sections as well as threshold pumping intensity for generation of laser radiation. Another sensitizer, Cr/sup 3+/, was added to Er/sup 3+/. The enhancement of absorption and emission of Er/sup 3+/ were investigated, in addition, the energy transfer efficiency from Cr/sup 3+/ to Er/sup 3+/ was determined from the emission of Cr/sup 3+/. The threshold, intensity for Er/sup 3+/ laser at 1543 nm is reduced to about 54 times using Yb/sup 3+/ as a sensitizer.
{"title":"Effect of sensitizers on the optical properties of Er/sup 3+/ ions in erbium glass lasers","authors":"A. Sattar, I. Azzouz, Mahmoud Shafik, Y. Badr","doi":"10.1109/PAIA.2002.995081","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995081","url":null,"abstract":"Two different host glasses for Er/sup 3+/, namely, phosphate and borate glasses were prepared. Yb/sup 3+/ was added as a sensitizer to investigate its effect on the absorption, emission, gain cross sections as well as threshold pumping intensity for generation of laser radiation. Another sensitizer, Cr/sup 3+/, was added to Er/sup 3+/. The enhancement of absorption and emission of Er/sup 3+/ were investigated, in addition, the energy transfer efficiency from Cr/sup 3+/ to Er/sup 3+/ was determined from the emission of Cr/sup 3+/. The threshold, intensity for Er/sup 3+/ laser at 1543 nm is reduced to about 54 times using Yb/sup 3+/ as a sensitizer.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128558138","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995080
H. Shalaby
A comparison between the performance of several optical code-division multiple-access (CDMA) correlation receivers is presented. The performance is measured in terms of an uncoded throughput capacity. It is defined as the maximum data rate (in nats/chip time) that can be achieved with arbitrary small error probability. Both on-off keying (OOK) and pulse-position modulation (PPM) CDMA schemes are considered. Signature code correlations bounded by either one or two are employed. Our results reveal that the throughput capacity of the optical PPM-CDMA systems can be increased by increasing the code-correlation constraint from one to two. That of OOK-CDMA systems, however, cannot be increased. Further, the throughput capacity of PPM-CDMA systems with code-correlation constraint of two is greater than that of OOK-CDMA systems with code-correlation constraint of one or two. In fact, this improvement in the throughput of PPM-CDMA systems over that of OOK-CDMA approaches a limiting factor of 10 as the pulse-position multiplicity increases to infinity.
{"title":"Uncoded throughput capacities of optical CDMA communication channels","authors":"H. Shalaby","doi":"10.1109/PAIA.2002.995080","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995080","url":null,"abstract":"A comparison between the performance of several optical code-division multiple-access (CDMA) correlation receivers is presented. The performance is measured in terms of an uncoded throughput capacity. It is defined as the maximum data rate (in nats/chip time) that can be achieved with arbitrary small error probability. Both on-off keying (OOK) and pulse-position modulation (PPM) CDMA schemes are considered. Signature code correlations bounded by either one or two are employed. Our results reveal that the throughput capacity of the optical PPM-CDMA systems can be increased by increasing the code-correlation constraint from one to two. That of OOK-CDMA systems, however, cannot be increased. Further, the throughput capacity of PPM-CDMA systems with code-correlation constraint of two is greater than that of OOK-CDMA systems with code-correlation constraint of one or two. In fact, this improvement in the throughput of PPM-CDMA systems over that of OOK-CDMA approaches a limiting factor of 10 as the pulse-position multiplicity increases to infinity.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127787194","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995078
A. Sallam, I.M. Kourah, S.A. Ziton, A. El-sayed, E.I. Badawy
With the emergence of bandwidth extensive communication demands, optical fiber communications arises as a suitable (and natural) solution. But with the wide bandwidth of the optical fibers, signal processing speed should exceed today's maximum electronic rates by about four orders of magnitude to be well utilized. In this paper, we describe a solution for the problem which is an all-optical discrete-time linear-time-invariant signal processor that can be reconfigured by an electronic microprocessor that gives it the flexibility and high speed. We first describe the basic idea and components of the processor, then we show its importance in optical communications such as in OCDM, OTDM, frequency-domain filtering within the same wavelength and dispersion equalization.
{"title":"All optical LTI systems","authors":"A. Sallam, I.M. Kourah, S.A. Ziton, A. El-sayed, E.I. Badawy","doi":"10.1109/PAIA.2002.995078","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995078","url":null,"abstract":"With the emergence of bandwidth extensive communication demands, optical fiber communications arises as a suitable (and natural) solution. But with the wide bandwidth of the optical fibers, signal processing speed should exceed today's maximum electronic rates by about four orders of magnitude to be well utilized. In this paper, we describe a solution for the problem which is an all-optical discrete-time linear-time-invariant signal processor that can be reconfigured by an electronic microprocessor that gives it the flexibility and high speed. We first describe the basic idea and components of the processor, then we show its importance in optical communications such as in OCDM, OTDM, frequency-domain filtering within the same wavelength and dispersion equalization.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133392070","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995085
G. E. Khalil, G. A. Fattah, Mahmoud Shafik, Y. Badr
Room temperature CW laser performance of 1% and 1.1% Nd:YAG with low power laser diode end-pumping has been studied. The results from Nd:YAG have been compared with the Nd:YLF at similar experimental conditions. The slope efficiency at 1064 nm was determined to be 14.7% for 1% Nd:YAG and 17.4% For 1.1% Nd:YAG laser crystal. For 1% Nd:YLF polarized laser at 1047 nm the efficiency was 6.2%. Laser output power dependencies on the pump power and the pump wavelengths of these diode-pumped solid state lasers were investigated.
{"title":"Comparison of CW laser performance of Nd:YAG and Nd:YLF under laser diode pumping","authors":"G. E. Khalil, G. A. Fattah, Mahmoud Shafik, Y. Badr","doi":"10.1109/PAIA.2002.995085","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995085","url":null,"abstract":"Room temperature CW laser performance of 1% and 1.1% Nd:YAG with low power laser diode end-pumping has been studied. The results from Nd:YAG have been compared with the Nd:YLF at similar experimental conditions. The slope efficiency at 1064 nm was determined to be 14.7% for 1% Nd:YAG and 17.4% For 1.1% Nd:YAG laser crystal. For 1% Nd:YLF polarized laser at 1047 nm the efficiency was 6.2%. Laser output power dependencies on the pump power and the pump wavelengths of these diode-pumped solid state lasers were investigated.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115183708","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995082
Y. Badr, N. Faharoff, M. Salah, E. Mohammed, N. Fathy
We built a pump probe technique set up to study the electron phonon coupling constant, and we determine its value to be = 0.707 /spl times/ 10/sup 12/ s/sup -1/.
{"title":"Pump probe technique","authors":"Y. Badr, N. Faharoff, M. Salah, E. Mohammed, N. Fathy","doi":"10.1109/PAIA.2002.995082","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995082","url":null,"abstract":"We built a pump probe technique set up to study the electron phonon coupling constant, and we determine its value to be = 0.707 /spl times/ 10/sup 12/ s/sup -1/.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134281627","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 : 2002-08-07DOI: 10.1109/PAIA.2002.995084
H. Maaty, A. Bashir, B. Saadany, D. Khalil
In this work, we study the effect of the shutter thickness on the optical attenuation in an optomechanical variable optical attenuator. Both experimental and simulation results show a maximum in the received optical field with the shutter displacement, which increases at large shutter thickness. This behaviour has not been reported or analysed before.
{"title":"Modelling and characterisation of a VOA with different shutter thickness","authors":"H. Maaty, A. Bashir, B. Saadany, D. Khalil","doi":"10.1109/PAIA.2002.995084","DOIUrl":"https://doi.org/10.1109/PAIA.2002.995084","url":null,"abstract":"In this work, we study the effect of the shutter thickness on the optical attenuation in an optomechanical variable optical attenuator. Both experimental and simulation results show a maximum in the received optical field with the shutter displacement, which increases at large shutter thickness. This behaviour has not been reported or analysed before.","PeriodicalId":287031,"journal":{"name":"Third Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes (Cat. No.02EX509)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126862828","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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