Pub Date : 2001-11-12DOI: 10.1109/LEOS.2001.969188
E. Wong, M. Summerfield
We have characterized our baseband carrier-sense circuit (BCSC) for use in future optical CSMA packet networks. The range of received optical power (ROP) for reliable operation at the circuit is bounded at the lower end where transmission collisions occur and at the higher end where transmission efficiency is compromised. A low low-pass filter (LPF) bandwidth benefits sensitivity, while a high LPF bandwidth benefits transmission efficiency. We found that for our BCSC implementation, an optimum LPF bandwidth exists that maximizes the operating range of ROP, but that the bandwidth dependence of this range is less than 1 dB between 100 kHz and 1 MHz.
{"title":"Performance of a baseband carrier-sense circuit for optical packet networks","authors":"E. Wong, M. Summerfield","doi":"10.1109/LEOS.2001.969188","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969188","url":null,"abstract":"We have characterized our baseband carrier-sense circuit (BCSC) for use in future optical CSMA packet networks. The range of received optical power (ROP) for reliable operation at the circuit is bounded at the lower end where transmission collisions occur and at the higher end where transmission efficiency is compromised. A low low-pass filter (LPF) bandwidth benefits sensitivity, while a high LPF bandwidth benefits transmission efficiency. We found that for our BCSC implementation, an optimum LPF bandwidth exists that maximizes the operating range of ROP, but that the bandwidth dependence of this range is less than 1 dB between 100 kHz and 1 MHz.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"114 1","pages":"91-92 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84179547","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969045
K. Oi, F. Barnier, M. Obara
The aim of this study is to fabricate and evaluate the transmission and reflection of FBGs induced by focused femtosecond laser interferometry. The two beams are focused inside the core, and the colliding angle is set in order to obtain an 2nd order Bragg reflection at around 1.45 /spl mu/m. The laser output power is varied using attenuators and adjusted not to reach the optical breakdown threshold at the focal spot. The transmission spectrum is examined simultaneously as the fabrication process is executed. The reflection spectrum is analyzed after fabrication has been completed.
{"title":"Fabrication of fiber Bragg grating by femtosecond laser interferometry","authors":"K. Oi, F. Barnier, M. Obara","doi":"10.1109/LEOS.2001.969045","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969045","url":null,"abstract":"The aim of this study is to fabricate and evaluate the transmission and reflection of FBGs induced by focused femtosecond laser interferometry. The two beams are focused inside the core, and the colliding angle is set in order to obtain an 2nd order Bragg reflection at around 1.45 /spl mu/m. The laser output power is varied using attenuators and adjusted not to reach the optical breakdown threshold at the focal spot. The transmission spectrum is examined simultaneously as the fabrication process is executed. The reflection spectrum is analyzed after fabrication has been completed.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"302 1","pages":"776-777 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76636159","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969250
O. Sinkin, J. Zweck, C. Menyuk
One of the principal problems in the design of high-data rate optical fiber communications systems is the choice of the modulation format. The conventional non-return-to-zero (NRZ) format was the first format employed in optical fiber communications, and it remains the predominant modulation scheme at this time. The NRZ format has evolved into the chirped return-to-zero (CRZ) format, where both phase and amplitude modulation are used to improve the system performance. At the same time, there has been a considerable amount of work done to investigate the possibility of using classical solitons in optical fiber communications. The classical soliton format eventually evolved into the dispersion-managed soliton (DMS) format. Classical and dispersion-managed solitons are similar in important respects. For example, the balance between chromatic dispersion and nonlinearity is the key condition for the existence of periodically stationary dispersion-managed solitons. By contrast, the CRZ pulse shape is not periodic and the pulse evolution is mostly determined by the dispersion. However, we find that with respect to nonlinear pulse interactions, the DMS and CRZ systems resemble each other and their behavior differs dramatically from that of classical soliton systems. We stress that in our work here, when we refer to a DMS system, we mean a periodically-stationary DMS system, rather than a quasilinear DMS system. The quasilinear DMS systems resemble CRZ systems more than they resemble the periodically-stationary DMS systems. We demonstrate that in the DMS and CRZ systems, the performance degrades as the number of frequency channels increases, as opposed to classical soliton systems, where adding channels does not affect the performance.
{"title":"A comparative study of pulse interactions in optical fiber transmission systems with different modulation formats","authors":"O. Sinkin, J. Zweck, C. Menyuk","doi":"10.1109/LEOS.2001.969250","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969250","url":null,"abstract":"One of the principal problems in the design of high-data rate optical fiber communications systems is the choice of the modulation format. The conventional non-return-to-zero (NRZ) format was the first format employed in optical fiber communications, and it remains the predominant modulation scheme at this time. The NRZ format has evolved into the chirped return-to-zero (CRZ) format, where both phase and amplitude modulation are used to improve the system performance. At the same time, there has been a considerable amount of work done to investigate the possibility of using classical solitons in optical fiber communications. The classical soliton format eventually evolved into the dispersion-managed soliton (DMS) format. Classical and dispersion-managed solitons are similar in important respects. For example, the balance between chromatic dispersion and nonlinearity is the key condition for the existence of periodically stationary dispersion-managed solitons. By contrast, the CRZ pulse shape is not periodic and the pulse evolution is mostly determined by the dispersion. However, we find that with respect to nonlinear pulse interactions, the DMS and CRZ systems resemble each other and their behavior differs dramatically from that of classical soliton systems. We stress that in our work here, when we refer to a DMS system, we mean a periodically-stationary DMS system, rather than a quasilinear DMS system. The quasilinear DMS systems resemble CRZ systems more than they resemble the periodically-stationary DMS systems. We demonstrate that in the DMS and CRZ systems, the performance degrades as the number of frequency channels increases, as opposed to classical soliton systems, where adding channels does not affect the performance.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"30 1","pages":"216-217 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82198505","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969285
Shuxian Song
Explicit formulas are derived for the number of four-wave mixing (FWM) waves that fall onto each signal channel in wavelength-division multiplexing (WDM) systems. These formulas indicate that the maximum number of FWM products on one channel in a WDM system has quadratic dependence on the number of channels. FWM crosstalk in WDM systems can be estimated by using these formulas in combining with other system parameters. They also provide a fast way to perform conversions on number of channels (or capacity) among different bit rates, such as 2.5, 10 and 40 Gbit/s, for given optical bandwidths of optical amplifiers.
{"title":"The number of four-wave mixing (FWM) waves in WDM systems and its applications","authors":"Shuxian Song","doi":"10.1109/LEOS.2001.969285","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969285","url":null,"abstract":"Explicit formulas are derived for the number of four-wave mixing (FWM) waves that fall onto each signal channel in wavelength-division multiplexing (WDM) systems. These formulas indicate that the maximum number of FWM products on one channel in a WDM system has quadratic dependence on the number of channels. FWM crosstalk in WDM systems can be estimated by using these formulas in combining with other system parameters. They also provide a fast way to perform conversions on number of channels (or capacity) among different bit rates, such as 2.5, 10 and 40 Gbit/s, for given optical bandwidths of optical amplifiers.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"23 1","pages":"283-284 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76443073","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969083
J. Roth, C. Xu, W. Knox, K. Bergman
Recently two-photon absorption (TPA) autocorrelation has attracted considerable attention because it achieves quadratic nonlinearity using simple direct electrical detection in a semiconductor material that eliminates the complexities involved with phase matching and polarization sensitivity when using a nonlinear crystal. The functional behavior of TPA depends upon peak power and average power. The remedy for low power situations typically involves boosting the power in an optical amplifier to perform the measurement, even though this degrades signal to noise ratio and distorts the pulseshape. This investigation reports on a novel TPA autocorrelation technique that uses a silicon avalanche photodiode (APD) to achieve enhanced sensitivity over other TPA techniques. The sensitivity of the APD, together with the lack of single-photon background events makes this method ideally suited for characterization of low power pulses.
{"title":"Ultra-sensitive autocorrelation at 1.5 /spl mu/m using a photon-counting silicon avalanche photodiode","authors":"J. Roth, C. Xu, W. Knox, K. Bergman","doi":"10.1109/LEOS.2001.969083","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969083","url":null,"abstract":"Recently two-photon absorption (TPA) autocorrelation has attracted considerable attention because it achieves quadratic nonlinearity using simple direct electrical detection in a semiconductor material that eliminates the complexities involved with phase matching and polarization sensitivity when using a nonlinear crystal. The functional behavior of TPA depends upon peak power and average power. The remedy for low power situations typically involves boosting the power in an optical amplifier to perform the measurement, even though this degrades signal to noise ratio and distorts the pulseshape. This investigation reports on a novel TPA autocorrelation technique that uses a silicon avalanche photodiode (APD) to achieve enhanced sensitivity over other TPA techniques. The sensitivity of the APD, together with the lack of single-photon background events makes this method ideally suited for characterization of low power pulses.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"29 1","pages":"851-852 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87548155","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969302
A. Loayssa, D. Benito, M. J. Garde
We propose a novel all-optical BPSK subcarrier modulator that provides a dispersion-tolerant output signal with enhanced optical modulation depth. Preliminary experiments transmitting a 2.8-GHz modulated subcarrier demonstrate the feasibility of the design.
{"title":"High-bit rate all-optical BPSK modulator for fiber-optic microwave/millimeter-wave links","authors":"A. Loayssa, D. Benito, M. J. Garde","doi":"10.1109/LEOS.2001.969302","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969302","url":null,"abstract":"We propose a novel all-optical BPSK subcarrier modulator that provides a dispersion-tolerant output signal with enhanced optical modulation depth. Preliminary experiments transmitting a 2.8-GHz modulated subcarrier demonstrate the feasibility of the design.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"29 1","pages":"316-317 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86165793","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969142
T. Sakurai
Summary form only given. Increased processing speed in electronics has given birth to new industries. Current computers and high-speed communication systems largely use technologies handling signals of a few 100 MHz up to the GHz range. Development of technologies handling very fast phenomena with precision of a few tens of femtoseconds and with a repetition rate in the THz range by simple and compact means could produce revolutionary change in systems, and surely will lead to a new industrial platform. To promote the research and develop such technologies handling ultra-fast phenomena, "The Femtosecond Technology Research Project" was started in 1995, sponsored by NEDO (New Energy and Industrial Technology Development Organization in Japan) as a ten-year project. This project set two major targets. One was to develop ultra-fast optical devices, which enable 1 Tb/s OTDM (optical time division multiplexed) transmission. The other is to develop compact ultra-short X-ray pulse sources for various diagnosis applications. The generation and control of ultra-short optical pulses are key issues in both targets.
{"title":"Femtosecond technology: a new industrial technology platform","authors":"T. Sakurai","doi":"10.1109/LEOS.2001.969142","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969142","url":null,"abstract":"Summary form only given. Increased processing speed in electronics has given birth to new industries. Current computers and high-speed communication systems largely use technologies handling signals of a few 100 MHz up to the GHz range. Development of technologies handling very fast phenomena with precision of a few tens of femtoseconds and with a repetition rate in the THz range by simple and compact means could produce revolutionary change in systems, and surely will lead to a new industrial platform. To promote the research and develop such technologies handling ultra-fast phenomena, \"The Femtosecond Technology Research Project\" was started in 1995, sponsored by NEDO (New Energy and Industrial Technology Development Organization in Japan) as a ten-year project. This project set two major targets. One was to develop ultra-fast optical devices, which enable 1 Tb/s OTDM (optical time division multiplexed) transmission. The other is to develop compact ultra-short X-ray pulse sources for various diagnosis applications. The generation and control of ultra-short optical pulses are key issues in both targets.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"44 1","pages":"3-4 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88839498","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 : 2001-11-12DOI: 10.1109/LEOS.2001.968981
Chun Zhang, Kwang-Su Lee, Xiang Zhang, X. Wei, Yaochun Shen
We have shown that the THz-time-domain spectroscopy technique can be used to measure accurately the refractive indices of crystalline ice in the THz range. Our 0.25-1.0 THz results bridge the gap between the microwave and the far IR regions. They agree very well with the curve extrapolated from the microwave data of T. Matsuoka et al. (1996), and provide an assessment of the reliability of the experimental data of others. It is found that the existing theoretical models describe well the refractive indices in this region.
我们已经证明，太赫兹时域光谱技术可以用来精确测量晶体冰在太赫兹范围内的折射率。我们的0.25-1.0太赫兹的结果弥补了微波和远红外区域之间的差距。它们与T. Matsuoka et al.(1996)从微波数据中推断出的曲线非常吻合，并提供了对其他人实验数据可靠性的评估。现有的理论模型较好地描述了该区域的折射率。
{"title":"THz spectroscopy of ice","authors":"Chun Zhang, Kwang-Su Lee, Xiang Zhang, X. Wei, Yaochun Shen","doi":"10.1109/LEOS.2001.968981","DOIUrl":"https://doi.org/10.1109/LEOS.2001.968981","url":null,"abstract":"We have shown that the THz-time-domain spectroscopy technique can be used to measure accurately the refractive indices of crystalline ice in the THz range. Our 0.25-1.0 THz results bridge the gap between the microwave and the far IR regions. They agree very well with the curve extrapolated from the microwave data of T. Matsuoka et al. (1996), and provide an assessment of the reliability of the experimental data of others. It is found that the existing theoretical models describe well the refractive indices in this region.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"6 1","pages":"646-647 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79632581","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 : 2001-11-12DOI: 10.1109/LEOS.2001.969248
D. Guney, T. Demirci, S. Isci, Y. Gurbuz, M. Naci Inci
The photonic crystal structure, considered in this work is a two-dimensional photonic band-gap slab which consists of triangular array of air holes etched into the substrate with one straight waveguide and isolated point defects. Because it is lossless through the spectral region chosen, optical properties of GaAs is used in this simulation. The structure was designed to have a complete band-gap for both TE-like and TM-like modes.
{"title":"Design and simulation of photonic crystals for temperature reading of ultra-small structures","authors":"D. Guney, T. Demirci, S. Isci, Y. Gurbuz, M. Naci Inci","doi":"10.1109/LEOS.2001.969248","DOIUrl":"https://doi.org/10.1109/LEOS.2001.969248","url":null,"abstract":"The photonic crystal structure, considered in this work is a two-dimensional photonic band-gap slab which consists of triangular array of air holes etched into the substrate with one straight waveguide and isolated point defects. Because it is lossless through the spectral region chosen, optical properties of GaAs is used in this simulation. The structure was designed to have a complete band-gap for both TE-like and TM-like modes.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"175 1","pages":"212-213 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79745405","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 : 2001-11-12DOI: 10.1109/LEOS.2001.968937
Y. Jiao, S. Bhalotra, H. L. Kung, David A. B. Miller
Collecting a spectrum for each pixel in an image can give much useful information about a scene, such as chemical content, but generates a vast amount of data. Optical filters can select specific spectral features in advance, but are difficult to adapt in real time to different desired spectra. We have constructed an imaging spectrometer using a time-domain filtering architecture, capable of real-time spectral feature extraction and adaptation to different desired spectra. We demonstrate in real-time the abilities both to (i) recognize multiple specific colors in an image, and (ii) recognize individual colors while suppressing combinations of the same colors, an example of a sophisticated signal processing function that can be performed in this architecture.
{"title":"Adaptive imaging spectrometer in a time-domain filtering architecture","authors":"Y. Jiao, S. Bhalotra, H. L. Kung, David A. B. Miller","doi":"10.1109/LEOS.2001.968937","DOIUrl":"https://doi.org/10.1109/LEOS.2001.968937","url":null,"abstract":"Collecting a spectrum for each pixel in an image can give much useful information about a scene, such as chemical content, but generates a vast amount of data. Optical filters can select specific spectral features in advance, but are difficult to adapt in real time to different desired spectra. We have constructed an imaging spectrometer using a time-domain filtering architecture, capable of real-time spectral feature extraction and adaptation to different desired spectra. We demonstrate in real-time the abilities both to (i) recognize multiple specific colors in an image, and (ii) recognize individual colors while suppressing combinations of the same colors, an example of a sophisticated signal processing function that can be performed in this architecture.","PeriodicalId":18008,"journal":{"name":"LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242)","volume":"189 1","pages":"558-559 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2001-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89280001","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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