Pub Date : 1995-05-01DOI: 10.1109/ARFTG.1995.327118
Y. Tkachenko, J. Bao, C. Wei, J.C.M. Hwang
Drain-gate breakdown of GaAs metal-semiconductor-field-effect transistors (MESFETs) was analyzed using high frequency waveform probing. Peak dmin-gate voltage was theoretically and experhentally found to be a determining breakdown factor. The impact ionization induced conduction component of the gate and drain current of pinched-off MESFET at RF was found to correspond to the dc breakdown currents. The transit time of 30 ps was obtained for the impact ionization generated electrons to travel from gate to drain. This yields the hot electron drift velocity of 4.3 X 106 cm/s which is in good agreement with the published data.
利用高频波形探测分析了砷化镓金属半导体场效应晶体管(mesfet)的漏极击穿。从理论上和技术上发现峰值门电压是一个决定性的击穿因素。在射频处，掐断MESFET的栅极和漏极电流的冲击电离诱导导通分量与直流击穿电流相对应。碰撞电离产生的电子从栅极到漏极的传递时间为30 ps。得到的热电子漂移速度为4.3 X 106 cm/s，与已发表的数据吻合较好。
{"title":"Waveform analysis of GaAs FET breakdown","authors":"Y. Tkachenko, J. Bao, C. Wei, J.C.M. Hwang","doi":"10.1109/ARFTG.1995.327118","DOIUrl":"https://doi.org/10.1109/ARFTG.1995.327118","url":null,"abstract":"Drain-gate breakdown of GaAs metal-semiconductor-field-effect transistors (MESFETs) was analyzed using high frequency waveform probing. Peak dmin-gate voltage was theoretically and experhentally found to be a determining breakdown factor. The impact ionization induced conduction component of the gate and drain current of pinched-off MESFET at RF was found to correspond to the dc breakdown currents. The transit time of 30 ps was obtained for the impact ionization generated electrons to travel from gate to drain. This yields the hot electron drift velocity of 4.3 X 106 cm/s which is in good agreement with the published data.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124452588","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636757
B.C. Gopal, F. Cho
It is well known that semiconductor optical amplifier (SOA) material is an ideal nonlinear material, which has not only a very high nonlinearity but also the signal gain. Using the gainsaturated SOA as a nonlinear interaction medium, all optical wavelength conversion at 20 Gb/s and all optical TDM demultiplexing at even higher bit rates have also been demonstrated. In this work we study the performance of using the SOA as an nonlinear interaction element for all optical wavelength conversion and switching/demultiplexing with a multiple of π phase-shift. We also demonstrate the idea of an all optical NOR (NAND for negative logic) gate based on a similar principle.
{"title":"Performance of all optical wavelength conversion, logic operation and switching using semiconductor optical amplifiers","authors":"B.C. Gopal, F. Cho","doi":"10.1109/SARNOF.1995.636757","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636757","url":null,"abstract":"It is well known that semiconductor optical amplifier (SOA) material is an ideal nonlinear material, which has not only a very high nonlinearity but also the signal gain. Using the gainsaturated SOA as a nonlinear interaction medium, all optical wavelength conversion at 20 Gb/s and all optical TDM demultiplexing at even higher bit rates have also been demonstrated. In this work we study the performance of using the SOA as an nonlinear interaction element for all optical wavelength conversion and switching/demultiplexing with a multiple of π phase-shift. We also demonstrate the idea of an all optical NOR (NAND for negative logic) gate based on a similar principle.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125072958","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636781
J. Catchmark, L. E. Rogers, R. Morgan, M. Asom, G. Guth, D. Christodoulides
We report the occurrence of higher-order transverse modes lasing in the individual elements of a two dimensional VCSEL array. Each of these modes couples coherently to form very distinct supermodes. In addition, very interesting polarization properties are observed. The TEM 0,1 mode is horizontally polarized along the [Oll] crystalline axis while all other modes are dominantly vertically polarized along the [011] axis.
{"title":"Optical characteristics of multi-transverse mode two dimensional vertical cavity top surface emitting laser arrays","authors":"J. Catchmark, L. E. Rogers, R. Morgan, M. Asom, G. Guth, D. Christodoulides","doi":"10.1109/SARNOF.1995.636781","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636781","url":null,"abstract":"We report the occurrence of higher-order transverse modes lasing in the individual elements of a two dimensional VCSEL array. Each of these modes couples coherently to form very distinct supermodes. In addition, very interesting polarization properties are observed. The TEM 0,1 mode is horizontally polarized along the [Oll] crystalline axis while all other modes are dominantly vertically polarized along the [011] axis.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129036035","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636612
V. Chan
It is argued that the drive towards a ubiquitous globally connected information network has begun. This exciting development for the 1990's has been stimulated by advancements of communications and networking technologies in many fkonts, including fiber, wireless, satellite communication and computer technologies. Ultimately all these disparate systems must be interconnected into a seamless web of interoperable communication and information networks, data bases, severs etc., that will eventually link businesses, schools, industxies and homes together. The types of services to be provided will be very broad, from entertainment to specialized computer communications for research, development and manufacturing. As the world proceeds to develop this global network, industries and governments will have to make some very hard choices that will affect the investment on research and development and ultimately the architecture and the physical hardware that would be put in place in the next decade or so. Since this next network promises to be large, extensive, costly and likely to be around for decades to come, it is important at this very critical juncture to ensure that all the critical issues are addressed and the appropriate architecture and hardware are inserted in the build-up.
{"title":"Architecture and technology for global networking","authors":"V. Chan","doi":"10.1109/SARNOF.1995.636612","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636612","url":null,"abstract":"It is argued that the drive towards a ubiquitous globally connected information network has begun. This exciting development for the 1990's has been stimulated by advancements of communications and networking technologies in many fkonts, including fiber, wireless, satellite communication and computer technologies. Ultimately all these disparate systems must be interconnected into a seamless web of interoperable communication and information networks, data bases, severs etc., that will eventually link businesses, schools, industxies and homes together. The types of services to be provided will be very broad, from entertainment to specialized computer communications for research, development and manufacturing. As the world proceeds to develop this global network, industries and governments will have to make some very hard choices that will affect the investment on research and development and ultimately the architecture and the physical hardware that would be put in place in the next decade or so. Since this next network promises to be large, extensive, costly and likely to be around for decades to come, it is important at this very critical juncture to ensure that all the critical issues are addressed and the appropriate architecture and hardware are inserted in the build-up.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113942639","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636715
Ligeng Xu, R. Taylor, S. Forrest
In this work we report the demonstration of the first coherent fiber-optic delay line which can introduce true time delays for signals from 0.8 GHz to 1.5 GHz. The frequency range in our experiments is only limited by the Mach-Zehnder modulator employed. The spurious free dynamic range limited by the third order inter-modulation (IM) distortion around 1 GHz is about 80 dB/Hz2/3, for a 5μW optical signal power and 80 pW local oscillator power. It is expected to be 100 dB/Hz2/3 or higher if a balanced receiver is used, and both the LO (local oscillator) and signal optical power are increased. We also describe a four-channel system to demonstrate the full delay switching mechanism.
{"title":"High frequency optically coherent analog antenna links","authors":"Ligeng Xu, R. Taylor, S. Forrest","doi":"10.1109/SARNOF.1995.636715","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636715","url":null,"abstract":"In this work we report the demonstration of the first coherent fiber-optic delay line which can introduce true time delays for signals from 0.8 GHz to 1.5 GHz. The frequency range in our experiments is only limited by the Mach-Zehnder modulator employed. The spurious free dynamic range limited by the third order inter-modulation (IM) distortion around 1 GHz is about 80 dB/Hz2/3, for a 5μW optical signal power and 80 pW local oscillator power. It is expected to be 100 dB/Hz2/3 or higher if a balanced receiver is used, and both the LO (local oscillator) and signal optical power are increased. We also describe a four-channel system to demonstrate the full delay switching mechanism.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131116300","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636717
K. Deng, K. Bergman
We provide a simple analysis to explain how the wavelength of a diode laser is shifted by the strong, incoherent optical feedback. Our preliminary experiments indicate that, in addition to wavelength changes, the laser diode's driving current is also extremely sensitive to the feedback. Thus, by detecting the bias current variations we could obtain similar nm ranging resolution without the complexity of a spectrometer. The technique can be made more compatible with integrated optics and existing technologies facilitating its applications in more difficult physical environments that may exist in industry or a medical'setting. Experimental results are provided that show 3-D surface structure imaging obtained by implementing this incoherent confocal laser-feedback technique in a scanning microscope.
{"title":"Nanometer-resolution distance and surface structure measurement bv incoherent laser-feedback","authors":"K. Deng, K. Bergman","doi":"10.1109/SARNOF.1995.636717","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636717","url":null,"abstract":"We provide a simple analysis to explain how the wavelength of a diode laser is shifted by the strong, incoherent optical feedback. Our preliminary experiments indicate that, in addition to wavelength changes, the laser diode's driving current is also extremely sensitive to the feedback. Thus, by detecting the bias current variations we could obtain similar nm ranging resolution without the complexity of a spectrometer. The technique can be made more compatible with integrated optics and existing technologies facilitating its applications in more difficult physical environments that may exist in industry or a medical'setting. Experimental results are provided that show 3-D surface structure imaging obtained by implementing this incoherent confocal laser-feedback technique in a scanning microscope.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133717951","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636764
C. Dupuy, D. Bull, D. Benenati, H. T. Simmonds, R. Fu
Summary form only given. Due to their high reliability, compact size, and ease of use, high power, fiber-coupled diode laser systems are attractive laser sources for surgical and therapeutic procedures. Applied Optronics Corporation has developed a system level approach to harnessing the optical power of multiple diode lasers and delivering that power through disposable optical delivery fibers fitted with standard optical connectors. The design is based on individual fiber-coupled diode lasers, whose individual output fibers are grouped together in a single optical connector. The total output power of the system scales linearly with the number of individual lasers. The emission wavelength or wavelengths of the system is determined by the choice of the individual lasers loaded into the system. A typical arrangement is one low power visible aiming laser and multiple high power infrared lasers. The individual lasers are arranged on a large thermal footprint, which limits the effect of mutual heating of adjacent lasers and allows for low intensity cooling techniques such as simple fans and heatsinking fins. The diode lasers themselves are single quantum well GRINSCH structures. The diode lasers are typically 100 pm wide 300 mW elements in the visible wavelengths, and 200 pm wide 1.8 watt elements at 980 nm. The laser output is coupled with efficiencies up to 75% into low NA (0.14) optical fibers. The users-supplied delivery fiber has a higher NA of 0.37 and a core size of 400 pm to 1000 pm depending on the system and total power requirements. The diode laser system itself is the size of personal computer, weighs less than 35 pounds, does not use cooling water and requires only a few amperes from a standard wall plug to deliver up to 50 Watt cw.
{"title":"High power, fiber-coupled diode laser systems: system design and medical applications","authors":"C. Dupuy, D. Bull, D. Benenati, H. T. Simmonds, R. Fu","doi":"10.1109/SARNOF.1995.636764","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636764","url":null,"abstract":"Summary form only given. Due to their high reliability, compact size, and ease of use, high power, fiber-coupled diode laser systems are attractive laser sources for surgical and therapeutic procedures. Applied Optronics Corporation has developed a system level approach to harnessing the optical power of multiple diode lasers and delivering that power through disposable optical delivery fibers fitted with standard optical connectors. The design is based on individual fiber-coupled diode lasers, whose individual output fibers are grouped together in a single optical connector. The total output power of the system scales linearly with the number of individual lasers. The emission wavelength or wavelengths of the system is determined by the choice of the individual lasers loaded into the system. A typical arrangement is one low power visible aiming laser and multiple high power infrared lasers. The individual lasers are arranged on a large thermal footprint, which limits the effect of mutual heating of adjacent lasers and allows for low intensity cooling techniques such as simple fans and heatsinking fins. The diode lasers themselves are single quantum well GRINSCH structures. The diode lasers are typically 100 pm wide 300 mW elements in the visible wavelengths, and 200 pm wide 1.8 watt elements at 980 nm. The laser output is coupled with efficiencies up to 75% into low NA (0.14) optical fibers. The users-supplied delivery fiber has a higher NA of 0.37 and a core size of 400 pm to 1000 pm depending on the system and total power requirements. The diode laser system itself is the size of personal computer, weighs less than 35 pounds, does not use cooling water and requires only a few amperes from a standard wall plug to deliver up to 50 Watt cw.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129653301","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636684
Y. Lan, C. Wei, J.C.M. Hwang
A new capacitance model for GaAs MESFETs suitable for bwdrain voltage operation is presented. The model includes, in addition to gate-bias dependence, drain-bias dependence of gate-source and gate-drain capacitances. The modeled capacitance values compare well with that extracted from measured S-parameters. The model bas been incorporated in a harmonic-balance commercial simulator, and the simulated MESFET power performance is in good agreement with measured data.
{"title":"A MESFET capacitance model for low-drain voltage operation","authors":"Y. Lan, C. Wei, J.C.M. Hwang","doi":"10.1109/SARNOF.1995.636684","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636684","url":null,"abstract":"A new capacitance model for GaAs MESFETs suitable for bwdrain voltage operation is presented. The model includes, in addition to gate-bias dependence, drain-bias dependence of gate-source and gate-drain capacitances. The modeled capacitance values compare well with that extracted from measured S-parameters. The model bas been incorporated in a harmonic-balance commercial simulator, and the simulated MESFET power performance is in good agreement with measured data.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115430442","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636730
S. Prokes
Although bulk silicon (Si) does not emit light in the visible part of the spectrum, porous silicon has been shown to emit light in the red. This material differs from bulk Si in one important way, that is, it consists of interconnected Si crystallites, having very large surface to volume ratios. The first emission mechanism proposed involved carrier recombination within quantum size Si particles, but more recent work has shown that surface emission models may be more likely. The problems with the quantum confinement model will be discussed in view of current data, and an oxygen center luminescence model will be discussed, with supporting experimental data.
{"title":"Mechanism of red light emission in porous silicon","authors":"S. Prokes","doi":"10.1109/SARNOF.1995.636730","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636730","url":null,"abstract":"Although bulk silicon (Si) does not emit light in the visible part of the spectrum, porous silicon has been shown to emit light in the red. This material differs from bulk Si in one important way, that is, it consists of interconnected Si crystallites, having very large surface to volume ratios. The first emission mechanism proposed involved carrier recombination within quantum size Si particles, but more recent work has shown that surface emission models may be more likely. The problems with the quantum confinement model will be discussed in view of current data, and an oxygen center luminescence model will be discussed, with supporting experimental data.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116141649","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 : 1995-04-28DOI: 10.1109/SARNOF.1995.636725
S. Singh, M. Carvalho, D. Christodoulides
A theory describing the propagation of orthogonally polarized spatial bright beams in a photorefractive crystal (SBN:60) is developed. The interaction between the two beams is further investigated numerically. We show that such a coupling can give rise to interesting effects like beam steering and beam compression.
{"title":"Interactions between orthogonally polarized optical beams in photorefractive media","authors":"S. Singh, M. Carvalho, D. Christodoulides","doi":"10.1109/SARNOF.1995.636725","DOIUrl":"https://doi.org/10.1109/SARNOF.1995.636725","url":null,"abstract":"A theory describing the propagation of orthogonally polarized spatial bright beams in a photorefractive crystal (SBN:60) is developed. The interaction between the two beams is further investigated numerically. We show that such a coupling can give rise to interesting effects like beam steering and beam compression.","PeriodicalId":118150,"journal":{"name":"IEEE Princeton Section Sarnoff Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122992968","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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