Abstract:

Abstract:

Abstract:Photonic crystal fibers (PCFs) with anomalous dispersion in short wavelength region are significant for some applications, such as short wavelength soliton propagation, super continuum generation and short pulse fiber lasing. In this paper, a systematic method for designing PCFs with required anomalous dispersion region is proposed by using a finite difference solver and the scaling transformation of the waveguide dispersion of PCFs. Designed PCF can be anomalously dispersive in the region less than 1.3 μm, which is very difficult to realize in the traditional standard single-mode fibers. The effectiveness of the proposed method is approved by numerical results. This work was supported by National Natural Science Foundation of China (No. 60407011 and No. 60277018) and Zhejiang Provincial Natural Science Foundation of China (No. Y104073)

Abstract:Interface characteristics possess very important influence on the performance of thin film devices. ITO/PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy (XPS) and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTCDA/p-Si, not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of Ols and Ols are more remarkable. Project is supported by the National Natural Science Foundation of China (Grant No 60076023)

Abstract:S-band gain flattened distributed fiber Raman amplifier with a bandwidth from 1 488 nm to 1 541 nm (53 nm in width), an averaged gain of 10 dB and a gain ripple of ±0.6 dB is obtained successfully, in which a single-wavelength high power fiber Raman laser with wavelength of 1 427.2 nm is used as the pump and the chirped fiber Bragg grating is used as the gain flattening filter. Besides, filter wavelength division multiplexer (FWDM) is used as the multi-signal multiplexer and 1 427 nm/1 505 nm coarse wavelength division multiplexer (CWDM) is used as the pump-signal coupler. The gain media are G652 fiber of 50 km in length and dispersion compensation fiber (DCF) of 5 km in length. Moreover, the location arrangements of different type of fibers and the effect caused by gain flattening filter as well as their solutions are discussed in detail. It is very significant to extend the range of optical fiber communication band and increase the capacity of fiber communication especially for ultra-long haul and ultra-high capacity communication system. This work was supported by the Great Scientific Research Project of Zhejiang Province, P. R. China (No. 021101558) and the Ministry of Science and Technology, Korea as a part of project funds of the Korea-China Optical Technology Research Center.

Abstract:With the appearance of this Editorial, we stand on the threshold of yet New Year, looking forward with glorious expectations. We take this opportunity to wish our readers, authors, reviewers, the members of the journal editorial board,

Abstract:Formulas of the transfer functions are presented for a series-coupled microring resonant filter and the filtering characteristics of this device are investigated around the central wavelength of 1.55 μm. The simulation results show that when the number of the microring is 4, the amplitude coupling ratio between the channel and the microring is 0.25, that between two microrings is 0.022, and the flat box-like spectral response can be formed. The 3-dB bandwidth is about 0.2 nm, the insertion loss is about 1.5 dB, and the minimum of non-resonant light is close to −150 dB. Supported by National 863-Projec (2001AA312160) & 973-Projec (G2000036604), the Chinese Academy of Sciences (One Hundred Talent Project) and the foundation of Changchun Institute of Optics Fine Mechanics and Physics, Chinese Academy of Sciences (c03Q14z)

Abstract:Silicon thin films with different crystalline ratio(Xc) have been deposited by varying silane content(SC) of reactive gases in the RF-PECVD process. The effects of silane content on performance of the materials and the relationship between microstructure and opto-electronic properties were studied by means of Raman measurements, photoconductivity (σ_ph), and dark conductivity (σ_d), followed by the measurements of light absorption coefficient (α), the product of quantum efficiency, mobility and lifetime (ημτ), before, during and after light soaking, respectively. The results indicate that the microcrystalline silicon near the transition region is suitable to prepare microcrystalline silicon of device grade, and that the amorphous region of the material is responsible to the light induced degradation. This work is supported by the State Key Development Program for Basic Research of China (Grant No. G2000028202, G2000028203), the Key Project of Education Bureau (Grant No. 02167) and the State Key Development Program (2002303261)

Abstract:In this letter, a new polarization state generator (PSG) is presented, which can generate an output with arbitrary state of polarization(SOP). This PSG consists of a linear polarizer, a rotatable quarter-waveplate, and a rotatable half-waveplate. The PSG can be used to study the polarization-related effects on optical components and on optical fiber communication systems. Supported by State “10-5” Project: “40 Gb/s SDH (STM-256) Optical Fiber Communications Equipments and Systems” (No. 2002BA106B07-5)

Abstract:In this paper, the low and the high frequency noises of a laser diode have been analyzed. Based on the analysis a novel scheme that adapts analog and digital hybrid techniques is proposed to stabilize the output power of a laser diode. With the hybrid controller, the low and the high frequency noises of a laser diode are conspicuously reduced. By accurate calculation, the short-term stability of the output power of laser diode reaches ±0.55‰, and the long-term stability is ±0.7‰. Supported by the National Natural Science Foundation of China (Grant No. F600077007) & Youth Science Foundation of Heilongjiang University (Grant No. QL200410)

Abstract:We present a novel and efficient L-band wavelength-tunable Er³⁺ doped fiber laser of ring structure. In the cavity two segments of Er³⁺ doped fiber and a fiber Bragg grating are used to improve pump efficiency. Tunable filters based on fiber loop mirrors are also applied inside the cavity to act as both a wavelength selector and a line-width compressor. Using these techniques, a tunable laser with tuning range up to 42 nm, output power larger than 1 mW, power uniformity controlled within 1.75 dB and side mode suppression ratio about 40 dB is achieved. This project (2005-28) is supported by Laboratory of Opto-electronics Information Technical Science, EMC.

Abstract:Based on the method of vector-field analysis, the relationship between the core-mode/cladding-mode coupling constantk _1v-11^cl-co and mode orderv is studied. It could be seen that the coupling constants of thel=1 low-orderHE cladding modes are larger than that of thel=1 low-orderEH cladding modes whenv≤41. For cladding modes withv>41, the coupling constants of thel=1 low-orderHE andEH modes are comparable to reach other. The plotted local intensity curves of the six lowest-order (l=1) cladding modes show that the low-orderHE modes have a larger proportion of intensity located in the core than the low-orderEH modes. Further, the relationship between the coupling constantk _1v-11^cl-co and the film refractive index as well as the film thickness is studied. The results indicate that the coupling constant changes monotonously with the film refractive index changing. As the film thickness increases, the coupling constant decreases slowly with irregularly changes in a certain region of the film thickness, which matches the experimental results of Nicholas D. R. Supported by Shu Guang Project (No: 02SG32) of the Education Committee of Shanghai and Shanghai Leading Academic Discipline Project (No: T0501)

Abstract:A double-prism adaptive optical design in surface plasma resonance (SPR) sensor is proposed, which consists of two identical isosceles right-triangular prisms. One prism is used as a component of Kretschmann configuration, and the other is for regulation of the optical path. When double-prism structure is angle-scanned by an immovable incident ray, the output ray will be always parallel with the incident ray and just has a small displacement with the shift of output point. The output ray can be focused on a fixed photodetector by a convex lens. Thus it can be avoided that a prism and a photodetector rotate by θ and 2θ respectively in conventional angular scanning SPR sensor. This new design reduces the number of the movable components, makes the structure simple and compact, and makes the manipulation convenient.

Abstract:In this paper, a novel method of laser beam deflecting is introduced to improve the spatial resolution of an acoustic-optic deflector (AOD). We use double AOD (DAOD) to control laser beam. Compared with single AOD, the double AOD can improve speed and precision of target tracking and pointing significantly. Finally, a method of calculating the static and dynamic number of resolvable poins (NRP) is and it is supported by the experimental data excellently.

Abstract:Theoretical analysis of the fiber-lens TEC (Thermally Expended Core)/Coreless/GRIN (Graded-Index) based on thin lens equivalence is presented in this paper. On condition that the TEC part adjusts the waist radius of an incident Gaussian beam, that the coreless part controlls the space between the beam waist and the thin lens, and that the GRIN part acts as the thin lens with its focal length determined by fiber index distribution parametereg, the analytic expressions of the waist spot size and the working distance of the output Gaussian beam are derived, and the influence of the coreless fiber and the length of the GRIN fiber upon the fiber-lens parameter is discussed based on the numerical simulation results. It is concluded that, if a GRIN style fiber-lens is used as a collimator, the maximum of the spot waist can be up to 80 μm and the divergence angle of single-mode optical fiber can be reduced by 8 times. If it is applied to a MEMS device, the maximum working distance can be up to 3 mm.

Abstract:Chiral molecule C₁₇H₁₇CIO₆ was incorporated in MMA by sol-gel process and its optical polarization response was measured. The optical rotatory dispersion was measured with self-manufactured apparatus. The results show that the maximum and minimum rotation angles of the chiral PMMA are 69° at the wavelength of 450 nm and 17° at the wavelength of 700 nm, respectively. The experimental results accord with the simulation results by the Boltzmann formula. Supported by the the Natural Science Foundation of China (No. 60307003, and Scientific Research Fund of Zhejiang Provincial Education Department (No. 20030436)

Abstract:Properties of photonic band gap and light propagation in one-dimensional multicomponent photonic crystal have been studied with the optical transfer matrix method. We mainly analyze the relation of photonic band-gap property with the arrangement of components, the refractive index and the geometrical thickness. In this study,the methods to change the width and the location of the existing photonic band-gaps in multicomponent photonic crystal are proposed.

Abstract:The samples of Au/(Si/SiO₂)/p-Si structure were fabricated by using the R. F magnetron sputtering technique. Its carrier transport and electroluminescence mechanism were studied from the I–V curves and EL spectra by using the Configuration Coordinate as a theoretical model. The result indicates that there are two defect centers in SiO₂ films., The electron in Au and the hole in p-Si went into SiO₂ film by the Fowler-Nordheim tunneling model at a high bias voltage and recombined through these defect centers in SiO₂ film.

Abstract:Sb2O3 doped ZnO thin film was prepared by RF magnetron sputtering technique. The influence of Sb2O3 on the structure and the optical absorption of ZnO thin film was studied by XPS,XRD apparatuses and UV-Vis spectrophotometer. The results show that doped Sb2O3 has affected atomic and electronic structures,growth modes of crystal grains and optical absorption of ZnO. The element Sb exists in many forms in the film including transpositional atoms and compounds such as Sb2O3, Zn7Sb2O14 etc. ZnO crystal grains grow in mixing directions. The lattice relaxation and the content of second phases increase when more Sb is doped. The UVA absorption of doped ZnO thin film increases obviously. The ultraviolet absorption peak narrows, absorption intensity increases, the absorption margin becomes steep and moves to shorter wavelength of about 5 nm, and the visible absorption increases in some sort.

Abstract:A scheme of WDM+OCDMA system employing optical hard-limiter (OHL) is proposed, and its performance of normalized throughput is analyzed. The upper bound of the normalized throughput is obtained when all the simultaneous users are equally allocated to different wavelength channels. The lower bound of the normalized throughput is obtained when all the simultaneous users are firstly allocated to the same wavelength channels. Compared with the performance of WDM+OCDMA system without OHL, both the upper bound and lower bound of the normalized throughput in WDM+OCDMA system with OHL can be improved. This work was supported by National Natural Science Foundation of China (No. 60132040); and Guangdong Provincial Natural Science Foundation of China (No. 5301028;04300855)

Abstract:Our work is based on the known research results of inherent optical quality of ocean color constituents. According to optimized parameters and induced fluorescence term of chlorophyll, this paper puts forward a remote sensing reflectance model of sea water, which is fitted in Liaodong Bay of Bohai. An inverse model that can evaluate redtide biomass according to chlorophyll retrieval is provided by inducing a functional extreme problem. The calculation example of the model indicates that the inversion model has explicit mathematic and physical meaning, but its practicability needs to be verified.

Abstract:A new algorithm for iterative reconstruction is suggested. It is named simple self-correlative algebraic reconstruction technique (SSART). With numerical simulation experiments, SSART was applied in reconstructing a non-ideal-bordered field in order to test its reconstructive effect. For contrast, three current representative algebraic reconstruction(ARTs) including basic ART, simultaneous ART (SART) and modified SART (MSART) were simulated simultaneously. The calculated results and reconstructive accuracy are discussed with three kinds of error indexes, namely mean-square error (MSE), absolute value error (AVE) and peak error (PE). As the results, the indexes of reconstructive accuracy are much improved by the proposed SSART. The MSE and PE have been decreased by 63.6% on the order of magnitude 10−4 and 88.9% on the order of magnitude 0–2, respectively, compared to that of ART. It is concluded that SSART is one of the most super iterative reconstructing techniques. This project was supported by China Postdoctoral Science Foundation (2004036121), the National Natural Science Foundation of China (10404022), and Education Bureau of Shandong province (J04A63)

Abstract:A method for reconstructing 3-D motion of coronary arteries from single-plane X-ray angiogram sequences on two approximately orthogonal views is proposed. 2-D motion is firstly estimated separately along vascular centerlines extracted from angiographic projection pairs. The 3-D displacement vector of each arterial skeleton point at one instant is then reconstructed by calculating the spatial coordinates of its two ends from corresponding projections. 3-D configuration and dynamics of arteries are finally characterized. The effectiveness of the algorithm has been demonstrated on vascular phantom images and clinical angiograms and results are encouraqing.

Abstract:A new way based on a modified bubble function and stationary wavelet transform (SWT) is proposed to solve the problem that the conventional edge detection algorithms are sensitive to the noises. Firstly, the traditional bubble function is modified in order to get different time-frequency domain responses and to get filtering effects through adjusting the parameters. Secondly, the modified bubble function is combined with SWT to construct a multiresolution network. By using the modified bubble function to enhance the edges and by using SWT to reduce the noises, the edges can be extracted accurately, effectively and quickly with lower noise. Finally, the experimental results of the proposed edge detection algorithm are verified to be better than that with the traditional bubble function. This research is supported by Research Fund for the Doctoral Program of Higher Education. NO.20020699014

Abstract:A method based on the wavelet transform is proposed for processing white light Interferograms from optical fiber interferometers. With this method, the envelope and the zero optical path difference (ZO-PD) of white light interferograms are obtained with high accuracy. The results agree well with those obtained by the method of center of gravity. Reasons for the insensitivity to noises of this method are discussed. The method is expected to be useful when processing white light interferograms from optical fiber interferometers, especially with low signal-to-noise ratio.

Abstract:The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a(AB) ^N (D)² (BA)^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain factor of the phase-conjugate wave is derived when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode. Because of stronger resonance enhancement to incident pump beam given by the Bragg microcavity, the enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium inside Bragg microcavity is more outstanding than that caused by the naked third order nonlinear optical medium. The theoretical analysis and the numerical calculation show the Bragg microcavity with larger numberN of periods is identical with a Fabry-Perot cavity when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode.

Abstract:Optoelectronics Lettersis the companionjournal toJour-nal of Optoelectronics·Laser(the core journal in Chi-nese) . The purpose ofOptoelectronics Lettersis rapidreporting newi mportant results in the fields of optoelec-tronics / photonics in Englishto adv…