Wu Ke, Wang Le, Yu Yi-Bo, Sun Da-Ming, Huang, Zhi-Yi, Gu Pei-Fu
Improving heat dissipation performance of LED lamps is of great significance to large-scale application of LED. The method of opening was adopted to modify the luminaires level heat dissipation structure in this study. Furthermore, natural convection heat rejection of LED lamp was simulated by computational fluid dynamics (CFD) method before and after the structural modification. As shown by computational results, opening was prone to forming bottom-up natural convection and achieved the goals of eliminating local circulation and improving heat transfer performance. Under the same...
TC2 Symposium 2010
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· 2010
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Huacai Chen, Jianjun Ma, Jiahua Chen, Wojtek J. Bock, Andrea Cusano
A novel optical fiber evanescent-wave (EW) sensing platform combining a taper and a refractive index (RI) gel residue is proposed. It includes two identical large core multimode fibers that are positioned perpendicularly to each other with one for excitation light delivery (i-fiber) and one for EW fluorescent signal collection (r-fiber). One end of the r-fiber is decladded to expose a segment of a cylindrical fiber core terminated with a taper. A small drop of rhodamine 6G (R6G) solution sample is distributed in such a way that it surrounds the side wall of the cylindrical portion of the...
TC2 Symposium 2010
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Filip Dvořák, Jan Maschke, Čestmír Vlček
The paper deals with effect of temperature field changes to the exposed length of polarization maintaining fiber (PMF). The change of output polarization state of propagating optical wave through the PMF were measured for input circular polarization which is invoking the excitation of both polarization states. This effect can be used to realization of sensor of temperature field disturbance, for example to detection of undesired person approach. To reach the maximal sensitivity of proposed sensor, the contemporary excitation of both polarization eigenmodes is required. The required...
TC2 Symposium 2010
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Hu Di, Zheng Cheng, Cao Xiangqun, Yuan Bo
This paper focuses on the principles and phenomena of the overlap pattern of the linear grating and zone plate. Deriving from the describing equations, it has been proved theoretically that the pattern also consists of zone plates, which are called moiré zone plates. The locations of the centers and the radius of the moiré zone plates are determined by the pitch of the linear grating, the first radius of the original zone plate and the phase of both of them. The fringe visibility is affected by the fill factor of linear grating and 0.5 results in the best visibility. Magnification, which is...
TC2 Symposium 2010
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Bobo Gu, Ming-Jie Yin, A. Ping Zhang, Jin-Wen Qian
A new fiber-optic pH sensor based on a thin-core fiber modal interferometer (TCFMI) with electrostatic self-assembled nanocoating is presented in this paper. By using layer-by-layer (LBL) electrostatic self-assembly technique, polydiallyldimethylammonium chloride (PDDA) and poly(acrylic acid) (PAA) are deposited on the side surface of TCFMI for pH sensing. Quartz crystal microbalance (QCM) is employed to monitor the thickness growth, and the morphology of the nanocoating is characterized by using atomic force microscopy (AFM). A linear, fast, and monotonic response of the sensor in both...
TC2 Symposium 2010
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Pei Li, Qi Chunhui, Ning Tigang, Li Zhuoxuan, Gao-song, Zhao Ruifeng
The multi-channel dispersion compensator by using chirped fiber Bragg gratings(CFBGs) has been one of the key technologies of high speed optical fiber communication system. The characteristics of reflection spectrum, time delay and dispersion of CFBGs with different connection forms are studied. By stress modulating and UV post-exposure, the uniform characteristics of the reflection spectrum of CFBGs are increased, and the influence of superposition effect caused by the parallel connection of CFBGs is decreased greatly. At the same time, the interference length is used to optimize the...
TC2 Symposium 2010
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Gregor Gerstorfer, Bernhard G. Zagar
This paper describes the use of a CD pickup head as a displacement measurement system. First, the components contained in a pickup head are explained and how they are combined to obtain the functionality of a pickup head. Afterwards, the application of measuring a knife edge profile is introduced.The results revealed some insuffiencies with the current system. Nevertheless, the cutting edge’s radius of curvature can be estimated.
TC2 Symposium 2010
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Ni Na
In recent years, optical fiber sensors have developed rapidly in Singapore. Nanyang Technological University, National University of Singapore and several research institutes under Agency for Science, Technology and Research (A*STAR) are studying on various types of optical fiber sensing devices for different applications. In this talk, we would like to briefly introduce the research work on optical fiber sensors area in Singapore. We will mainly present the contributions of Institute for infocomm Research (I2R) in A*STAR and Network Technology Research Center (NTRC) in Nanyang Technological...
TC2 Symposium 2010
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Tilo Pfeifer , Robert Schmitt , Niels König, Guilherme Francisco Mallmann
The measurement of boreholes with diameters smaller than 500 microns is a demanding task, which cannot be coped with state-of-the-art production metrology. Within this paper, the set-up of a miniaturized fiber probe with a diameter of 80 microns is presented. The probe is used for low-coherence interferometry for the highly precise measurement of form deviations of small boreholes. Measurements, which have been conducted in nozzles, are presented. The results prove the potential of the fiber-optical sensor for the quality inspection of high-precision parts such as injection nozzles for...
TC2 Symposium 2010
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Chun-Liu Zhao
In this paper, we investigate in detail the characteristics of a LPG written in an endlessly-single-mode (ESM) solid silica core PCF both theoretically and experimentally. By use of a dispersion factor, a deeper understanding of the behavior of LPG in the ESM-PCF is achieved. Our analysis clearly reveals the significant effect of the waveguide dispersive characteristics of the cladding modes on the strain and temperature characteristics of the LPG in the ESM-PCF. By selecting an appropriate grating period, a LPG with approximately zero temperature sensitivity but large strain sensitivity is...
TC2 Symposium 2010
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