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23rd International Conference on optical Fibre Sensors

作者： Le Floch, S. Sauser, F. Llera, M. Rochat, E. HE ARC Rue Serre 7 CH-2610 St Imier Switzerland Omnisens SA CH-1110 Morges Switzerland

ISBN: (纸本)9781628411751

In this paper, we propose a new Brillouin optical Time Domain Analysis (BOTDA) set-up that combines simultaneous Brillouin gain/loss measurements with colour coding. This technique gives the advantage that the pump power can greatly be increased, compared to other coding schemes, thus increasing the sensing range. A measurement over a 200 km fiber-loop is performed, with a 3 meter spatial resolution and an accuracy of +/-3 MHz (2 sigma) at the end of the sensing fiber. To the best of our knowledge, this is the best result obtained with a Brillouin sensor without Raman amplification.

关键词： stimulated Brillouin scattering fiber optics sensors distributed fiber sensors optical coding

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Wave-front coded optical readout for the MEMS-based uncooled infrared imaging systemaf

Wave-front coded optical readout for the MEMS-based uncooled...

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Conference on optical Design and Testing V

作者： Li, Tian Zhao, Yuejin Dong, Liquan Liu, Xiaohua Jia, Wei Hui, Mei Yu, Xiaomei Gong, Cheng Liu, Weiyu Beijing Inst Technol Sch Optoelect Beijing 100081 Peoples R China Peking Univ Inst Microelect Natl Key Lab Nano/Micro Fabrica Technol Beijing 100871 Peoples R China

ISBN: (纸本)9780819493125

In the space limited infrared imaging system based MEMS, the adjustment of optical readout part is inconvenient. This paper proposed a method of wave-front coding to extend the depth of focus/field of the optical readout system, to solve the problem above, and to reduce the demanding for precision in processing and assemblage of the optical readout system itself as well. The wave-front coded imaging system consists of optical coding and digital decoding. By adding a CPM (Cubic Phase Mask) on the pupil plane, it becomes non-sensitive to defocussing within an extended range. The system has similar PSFs and almost equally blurred intermediate images can be obtained. Sharp images are supposed to be acquired based on image restoration algorithms, with the same PSF as a decoding core. We studied the conventional optical imaging system, which had the same optical performance with the wave-front coding one for comparing. Analogue imaging experiments were carried out. And one PSF was used as a simple direct inverse filter, for imaging restoration. Relatively sharp restored images were obtained. Comparatively, the analogue defocussing images of the conventional system were badly destroyed. Using the decrease of the MTF as a standard, we found the depth of focus/field of the wave-front coding system had been extended significantly.

关键词： CPM depth of focus optical coding digital decoding infrared imaging

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Fluorescent magnetic emulsion droplets: Potential material for multiplexed optical coding of biomolecules

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JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 2007年第1期311卷 88-91页

作者： Mandal, Swapan K. Visva Bharati Univ Dept Phys Santini Ketan 731235 W Bengal India

Fluorescent magnetic microbeads can be potentially used in optical coding of biomolecules. The currently commercially available microbeads so far suffer polydispersity in both size and fluorescence intensity. Large statistical fluctuations in intensity level are quite detrimental for their use in optical coding applications. To optimize them for multiplexed optical coding of biological molecules, besides monodispersity, statistical fluctuations in intensity of beads need to be maintained as low as possible (< 1 % and less) in order to obtain a large number of codes. Here, we show that fluorescent and magnetic droplets synthesized through a simple and elegant oil-in-water microemulsion technique can have statistical fluctuations as low as < 1 % with a number of fluorescent labels. (C) 2006 Elsevier B.V. All rights reserved.

关键词： magnetic droplet emulsion optical coding fluorescence

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Synchronous optical CDMA Networks Capacity Increase Using Transposed Modified Prime Codes

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2010年第17期28卷 2603-2610页

作者： Karbassian, M. Massoud Kueppers, Franko Univ Arizona Coll Opt Sci Tucson AZ 85721 USA

A novel spreading code-set based on the prime code (PC) families, referred to as 'transposed modified prime codes (T-MPC)', is proposed for synchronous optical code-division multiple-access (OCDMA) networks. The new code-set is constructed algorithmically to enhance and simplify its implementation. The proposed code-set performance is compared with existing spreading code families in terms of correlations, bit-error rate (BER) and cardinality. The proposed optical spreading code family doubles the cardinality as compared to existing PC families. This also implies that greater number of users can be accommodated in the network. Since there is no longer a time-shift feature in T-MPC like in conventional modified prime codes (MPC), the code is not predictable and thus even more secure. However, the code structure is similar to MPC, thus its employment in a system running MPC will be nondestructive. The code is also compatible with low-weight MPC. The results indicate that the proposed code-set has properties to enhance the OCDMA network capacity remarkably.

关键词： Multiple-user interference optical CDMA optical coding prime codes spreading code design

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All-optical analog-to-digital conversion system with a spatial coding method using designed filter

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optical REVIEW 2009年第2期16卷 184-187页

作者： Kato, Takuya Konishi, Tsuyoshi Nishitani, Takashi Itoh, Kazuyoshi Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan

We propose and demonstrate an all-optical analog-to-digital conversion system with a spatial coding method using a designed filter. To make available codes more flexible, the design technique for a computer-generated hologram is introduced to our spatial coding scheme. By designing the spatial coding filter appropriately, this coding scheme enables us to output various digital signals as spatial patterns. By combining this coding method with the optical quantization method using soliton self-frequency shifting in a fiber, the proposed system converts analog sampled signals into arbitrary digital signals. Preliminary experimental results show that 3-bit Gray codes are successfully output as spatial patterns using the designed spatial coding filter.

关键词： optical signal processing optical analog-to-digital conversion optical coding computer-generated hologram (CGH) nonlinear fiber optics free space optics soliton self-frequency shift (SSFS)

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Method of digital hologram synthesis for hidden image optical coding in holographic security devices

Method of digital hologram synthesis for hidden image optica...

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Conference on Speckles, From Grains to Flowers

作者： Lymarenko, Ruslan Budnyk, Oksana Natl Acad Sci Ukraine Int Ctr Inst Appl Opt 10-G Kudryavska Str UA-04053 Kiev Ukraine

ISBN: (纸本)0819464260

The methods of increase the protective properties of holographic elements by using hidden image are discussed. The extension of the new method of wave equation solution is useful for providing analytical studying and numerical modeling of diffraction on amplitude-phase discrete mask. Possibilities of its practical application for structured light beam generation and wavefront reconstruction is considered. Conclusions regarding the possibilities of the representation of the arbitrary fields by using the discrete matrix of elementary diffractive aperture cells for an enhancement of the iteration algorithm of hologram synthesis are obtained. The method proposed of computer-generated holograms (CGH) synthesis enables one to synthesize CGH's and to simulate the digital image processing techniques for hidden image coding. The further improvement of this approach of coding amplitude-phase masks for both recording and reading of hidden image by holographic security devices is proposed. By using coding phase mask with quasi-stochastic distribution for diffraction pattern writing as additional structure on the protective hologram are explained. It is shown that computer generated hologram (CGH) can restore spatial structure represented by optical singularities. The conditions of reconstruction of the hidden image are discussed in case of encoding and decoding masks are not coinciding. A structure of a system that looks promising to produce a like hologram and method of operation directly images a pattern, which is previously calculated by computer and displayed on the amplitude-phase mask is explained. The results obtained by numerical and experimental means are accompanied with a discussion about extents of this method.

关键词： optical coding hidden image holographic security device

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Droplet microfluidic technology for single-cell high-throughput screening

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2009年第34期106卷 14195-14200页

作者： Brouzes, Eric Medkova, Martina Savenelli, Neal Marran, Dave Twardowski, Mariusz Hutchison, J. Brian Rothberg, Jonathan M. Link, Darren R. Perrimon, Norbert Samuels, Michael L. RainDance Technol Lexington MA 02421 USA Howard Hughes Med Inst Boston MA 02115 USA Harvard Univ Sch Med Dept Genet Boston MA 02115 USA

We present a droplet-based microfluidic technology that enables high-throughput screening of single mammalian cells. This integrated platform allows for the encapsulation of single cells and reagents in independent aqueous microdroplets (1 pL to 10 nL volumes) dispersed in an immiscible carrier oil and enables the digital manipulation of these reactors at a very high-throughput. Here, we validate a full droplet screening workflow by conducting a droplet-based cytotoxicity screen. To perform this screen, we first developed a droplet viability assay that permits the quantitative scoring of cell viability and growth within intact droplets. Next, we demonstrated the high viability of encapsulated human monocytic U937 cells over a period of 4 days. Finally, we developed an optically-coded droplet library enabling the identification of the droplets composition during the assay read-out. Using the integrated droplet technology, we screened a drug library for its cytotoxic effect against U937 cells. Taken together our droplet microfluidic platform is modular, robust, uses no moving parts, and has a wide range of potential applications including high-throughput single-cell analyses, combinatorial screening, and facilitating small sample analyses.

关键词： cell encapsulation viability assay lab-on-a-chip emulsion optical coding

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WDM Passive optical Networks and Beyond: the Road Ahead [Invited]

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JOURNAL OF optical COMMUNICATIONS AND NETWORKING 2009年第4期1卷 C1-C16页

作者： Maier, Martin Univ Quebec INRS Opt Zeitgeist Lab Montreal PQ H3C 3P8 Canada

After discussing point-to-point fiber-to-the-home, WDM passive optical networks (PONs), and multistage WDM PON networks and elaborating on their respective advantages and limitations, I attempt to lift the veil of next-generation WDM PON topologies and optical network unit architectures while paying close attention to their smooth evolutionary migration path from current TDM PONs. I introduce optical coding enhanced WDM PONs that allow for enhanced real-time dynamic bandwidth allocation and outline future research avenues.

关键词： Real-time DBA FiWi Home networking NG-PON optical coding optical-wireless integration PON WDM

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PON Monitoring: Periodic Encoders With Low Capital and Operational Cost

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IEEE PHOTONICS TECHNOLOGY LETTERS 2008年第21-24期20卷 2039-2041页

作者： Fathallah, Habib Rad, Mohammad M. Rusch, Leslie A. Univ Laval Dept Elect & Comp Engn COPL Quebec City PQ G1V 0A6 Canada

We propose a novel and simple coding device for centralized monitoring of passive optical networks. Encoders have dual Bragg gratings forming a cavity producing periodic codes. These encoders reduce the cost of manufacturing, installation, inventory, and operation, while maintaining good performance and high capacity. We evaluate monitoring efficiency in terms of signal-to-noise ratio.

关键词： Monitoring network management optical code-division multiplexing (OCDM) optical coding passive optical network (PON) signal-to-noise ratio (SNR)

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Coded optical time domain reflectometry : principle and applications

Coded optical time domain reflectometry : principle and appl...

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Conference on Passive Components and Fiber-Based Devices IV

作者： Park, Namkyoo Lee, Jeonghwan Park, Jonghan Shim, Jae Gwang Yoon, Hosung Kim, Jin Hee Kim, Kyoungmin Byun, Jae-Oh Bolognini, Gabriele Lee, Duckey Di Pasquale, Fabrizio Seoul Natl Univ Sch EECS Photon Syst Lab Seoul 151744 South Korea Network Inframat Lab KT Corp FTTH Solution Dev Dept Daejeon 305811 South Korea Luxpert Technologies Co Ltd Seoul 152768 South Korea Scuola Superiore Sant Anna I-56124 Pisa Italy

ISBN: (纸本)9780819469441

In this paper, we will briefly outline our contributions for the physical realization of coded OTDR, along with its principles and also highlight recent key results related with its applications. For the communication network application, we report a multi-port / multi-wavelength, high-speed supervisory system for the in-service monitoring of a bidirectional WDM-PON system transmission line up to 16 ports x 32 nodes (512 users) capacity. Monitoring of individual branch traces up to 60 km was achieved with the application of a 127-bit simplex code, corresponding to a 7.5dB SNR coding gain effectively reducing the measurement time about 30 times when compared to conventional average mode OTDR. Transmission experiments showed negligible penalty from the monitoring system to the transmission signal quality, at a 2.5Gbps / 125Mbps (down / up stream) data rate. As an application to sensor network, a Raman scattering based coded-OTDR distributed temperature sensor system will be presented. Utilizing a 255-bit Simplex coded OTDR together with optimized sensing link (composed of cascaded fibers with different Raman coefficients), significant enhancement in the interrogation distance (19.5km from coding gain, and 9.6km from link-combination optimization) was achieved to result a total sensing range of 371an (at 17m/3K spatial/temperature resolution), employing a conventional off-shelf low power (80mW) laser diode.

关键词： optical time domain reflectometery (OTDR) optical coding fiber to the home (FTTH) wavelength division multiplexed passive optical network (WDM-PON) distributed temperature sensor (DTS)

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