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Synchronous optical CDMA Networks Capacity Increase Using Transposed Modified Prime Codes

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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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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Integration of a proposed all-optical analog-to-digital converter using self-frequency shifting in fiber and a pulse-shaping technique

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optical REVIEW 2005年第3期12卷 237-241页

作者： Nishitani, T Konishi, T Itoh, K Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan

Integration of a proposed all-optical analog-to-digital (A/D) converter is described. To realize a high-speed and high-throughput system, optical A/D conversion has attracted much attention. A/D conversion generally consists of three processes of sampling, quantization and coding. Whereas an optical sampling technique has already been realized, there have been few investigations on the optical quantization and optical coding technique. We previously proposed an all-optical A/D converter which realizes both optical quantization and optical coding. In this paper, we integrate the proposed all-optical A/D converter to improve its performance and stability. We verify the operation of the integrated all-optical A/D converter composed of a short high nonlinear fiber, arrayed waveguide gratings and variable optical attenuators. (c) 2005 The optical Society of Japan.

关键词： optical analog-to-digital conversion ultra-short pulse self-frequency shift time-space conversion arrayed waveguide grating optical thresholding optical quantization optical coding

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Spatial Hadamard Encoding with Difference Frequency Generation 23

Spatial Hadamard Encoding with Difference Frequency Generati...

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Conference on Nonlinear Frequency Generation and Conversion - Materials and Devices XXIII

作者： Xu, Yang Tang, Sirui Black, A. Nicholas Boyd, Robert W. Univ Rochester Dept Phys & Astron Rochester NY 14627 USA Univ Rochester Inst Opt Rochester NY 14627 USA Univ Ottawa Dept Phys Ottawa ON K1N 6N5 Canada Univ Calif Berkeley Dept Elect Engn Berkeley CA USA

ISBN: (纸本)9781510669994;9781510669987

Orthogonal optical coding is widely used in classical multi-user communication networks. Using the phase conjugation property of stimulated parametric down-conversion, we extend the current time-domain orthogonal optical coding scheme to the spatial domain to encode and decode image information. In this process, the idler beam inherits the complex conjugate of the field information encoded in the seed beam. An encoding phase mask introduced onto the input seed beam blurs the image transferred to the idler. The original image is restored by passing the coded transferred image through a corrective phase mask placed in the momentum space of the idler beam. We expect that this scheme can also inspire new techniques in secure image transmission, aberration cancellation, and frequency conversion imaging.

关键词： Nonlinear Optics optical coding

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Brillouin distributed sensor over a 200 km fiber-loop using a dual-pump configuration and colour coding

Brillouin distributed sensor over a 200 km fiber-loop using ...

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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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Colour cyclic code for Brillouin distributed sensors 24

Colour cyclic code for Brillouin distributed sensors

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24th International Conference on optical Fibre Sensors (OFS)

作者： Le Floch, Sebastien Sauser, Florian Llera, Miguel Rochat, Etienne HE ARC CH-2610 St Imier Switzerland Omnisens SA CH-1110 Morges Switzerland

ISBN: (纸本)9781628418392

For the first time, a colour cyclic coding (CCC) is theoretically and experimentally demonstrated for Brillouin optical time-domain analysis (BOTDA) distributed sensors. Compared to traditional intensity-modulated cyclic codes, the code presents an additional gain of root 2 while keeping the same number of sequences as for a colour coding. A comparison with a standard BOTDA sensor is realized and validates the theoretical coding gain.

关键词： Stimulated Brillouin scattering fiber-optics sensors distributed fiber sensors optical coding

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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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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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New improvements for Brillouin optical time-domain reflectometry 25

New improvements for Brillouin optical time-domain reflectom...

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25th International Conference on optical Fibre Sensors (OFS)

作者： Le Floch, Sebastien Sauser, Florian Univ Appl Sci Western Switzerland Haute Ecole ARC Ingn Rue Serre 7 CH-2610 St Imier Switzerland

ISBN: (纸本)9781509048502

This paper presents new techniques designed to improve the performances of a BOTDR. The first one introduces a second pump to the sensor, thus doubling the Brillouin signal on the receiver. The second one uses image processing with a two-dimensional Gaussian filter whose parameters are defined. The last technique explores the possibilities offered by colour codes. The benefits of each, in terms of signal-to-noise ratio, is presented by comparing measurements over a distance range of 50km with a spatial resolution of 5m. These techniques can easily be combined and the global improvement is estimated at 10dB, compared to conventional sensors.

关键词： Spontaneous Brillouin scattering distributed fiber sensors optical coding image processing

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Can wavefront coding infrared imaging system achieve decoded images approximating to in-focus infrared images?

Can wavefront coding infrared imaging system achieve decoded...

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International Conference on Frontiers in optical Imaging Technology and Applications / International Symposium on Terahertz Technology and Applications / International Symposium on Surface Topography and optical Microscopy

作者： Feng, Bin Zhang, Chengshuo Xu, Baoshu Shi, Zelin Chinese Acad Sci Shenyang Inst Automat Shenyang 110016 Peoples R China Chinese Acad Sci Key Lab Optoelect Informat Proc Shenyang 110016 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

ISBN: (纸本)9781510601680

Artefacts and noise degrade the decoded image of a wavefront coding infrared imaging system, which usually results in the decoded image being inferior to the in-focus infrared image of a conventional infrared imaging system. The previous letter showed that the decoded image fell behind the in-focus infrared image. For comparison, a bar target experiment at temperature of +20 degrees C and two groups of outdoor experiments at temperatures of +28 degrees C and +70 degrees C are respectively conducted. Experimental results prove that a wavefront coding infrared imaging system can achieve the decoded image being approximating to its corresponding in-focus infrared image.

关键词： Wavefront coding optical coding digital decoding infrared imaging athermalization

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