Abstract:A novel 2×2 wavelength selective cross-connect (WSXC) module, which is composed of a Bragg-grating-based Mach-Zehnder interferometer (MZI), a pair of optical waveguides, a pair of 1×2optical switches (OSWs) and a pair of Y-model combiners is proposed. The mathematical description of the proposed 2×2 WSXC module is given and explained. Multichannel multi-wavelength selective cross-connect can be fabricated with the proposed 2×2 WSXC module, together with multistage interconnection networks (MINs). A four-wavelength 4×4 WSXC is demonstrated by simulation to validate the flexibility of the proposed WSXC.

Abstract:This letter reports on new types of photo resists allowing UV-light exposure of thick layers. Optimized processes Cthat for the positive resistAZ 9260 and the negative resist Epon SU-8 have been developed enabling the fabrication of high aspect ratio metallic and polymer micro components. The high potential of this technology will be demonstrated on the basis of two examples, a variable reluctance micro motor with compensated attractive force and an optical microphone developed for application in electro-magnetic interference en environments.

Abstract:1.55-μm InGaAsP-InP two-section DFB lasers with varied ridge width, both gain-coupled and index-coupled, have been fabricated. Self-pulsations with frequencies around 40 GHz are observed. The related mechanism and the tunability of generated self-pulsations is studied.

Abstract:Based on the variational analysis of the Er -Yb co-doped glass optical waveguide,the dependence of the mode profiles and propagation characteristics on the fabrication parameters, mainly on the channel waveguide width and the annealing time,are investigated. Different influences of these parameters on the mode dimensions, the center position of the depth field profile, the effective refractive index, and overlap factor are shown in this letter, according to which the appropriate preparation conditions can be chosen.

Abstract:The stimulated Raman amplification of picosecond Stokes pulse is numerically investigated in ultra-small silicon-oninsulator optical waveguide. Numerical results show that we obtain the gain of up to 30-dB for weak Stokes pulse in the copropagation configuration for 10 mm Jength waveguide using high intensity pump optical pulse. The peak gain, pulse width, rise time, and fall time of Stokes pulse will experience the variation course of decaying then increasing with increasing waveguide length. The time delay of output Stokes pulse is controlled by adjusting the initial time delay of both pump and Stokes pulses.

Abstract:A novel 2×2 wavelength selective cross-connect (WSXC) module, which is composed of a Bragg-grating-based Mach-Zehnder interferometer (MZI), a pair of optical waveguides, a pair of 1×2 optical switches (OSWs) and a pair of Y-model combiners is proposed. The mathematical description of the proposed 2×2 WSXC module is given and explained. Multi-channel multi-wavelength selective cross-connect can be fabricated with the proposed 2×2 WSXC module, together with multistage interconnection networks (MINs). A four-wavelength 4×4 WSXC is demonstrated by simulation to validate the flexibility of the proposed WSXC. This work has been supported in part by the Natural Science Foundation of China (No.60677023) and by Hi-Tech Research and Development Program of China (No. 2006AA01Z240).

Abstract:A High birefringence microstructure fiber with four big elliptical air holes is investigated by using the finite-difference frequency-domain (FDFD) method. Based on the numerical simulations, the influence of the air-hole size and pitch upon the mode birefringence is analyzed. The work may be helpful for the design and fabrication of high birefringence PCFs.

Abstract:The 1064 nm pulsed laser was used to ablate polyethylene (PE) at different power. Compared with unmodified PE, the ablated polyethylene (PE) gave off obvious blue light under UV lamp irradiation. The morphology and tre structure of ablated and unmodified PE were studied by scanning electron microscope, fluorescence spectroscopy and raman spectroscopy.the results showed that double bonds existed in the ablated PE which resulted in obvious blue emission of ablated PE and the intensity of the laser had great influence on the physical properties and chemical structure of the PE surface.

Abstract:Highly efficient white phosphorescent organic light-emitting devices (WOLEDs) was fabricated using an electron/exciton blocker. The device structure is ITO/2T-NATA(25 nm)/NPBX(25-dnm)/CBP:5%Ir(ppy)3:0.5%Rubrene(8 nm)/NPBX(dnm)/DPVBi(30 nm)/TPBi(20 nm)/Alq(10nm)/LiF(1nm)/Al, in which N,N' -bis- (1-naphthyl)- N,N' -dipheny1-1, 1' - bi-phenyl-4,4 ' -diamine (NPBX) functions as a hole transport layer and electron/exciton blocker, 4,4,N,N 'dicarbazolebiphenyl (CB P) is host, 4,4' -bis(2,2 -diphenyl vinyl)-1,1' -biphenyl (DPVB. i) is blue fluorescent dye, 5,6,11,12,-tetraphenylnaphthacene (rubrene) is fluorescent dye, factris (2-phenylpyridine) iridium (Ir(ppy)3) is phosphorescent sensitizer and tris(8-hydroxyquinoline) aluminum (Alq3) is an electron transport layer. The WOLEDs have obtained white light emission by adjusting the thickness of NPBX, when the concentration of Ir(ppy)3 is 5-wt% and rubrene is 0.5-wt%,respectively, the thickness of the doped emissive layer is 8 nm, the WOLEDs show a maximum luminous efficiency is 11.2 cd/A with d of 10 nm at 7 V and a maximum luminance of 28170 cd/m2 at 17 V, the CIE coordinates is (0.37.0.42), which is in white region.

Abstract:A birefringence photonic crystal fiber is used for PMD compensation in a single-channel 40Gbit/s-speed optical communication system with CSRZ format. The experimental results of transmission show that the PMD compensation system works effectively.

Abstract:A scheme for all-optical NOR logic gate is proposed based on injection-locking effect in a semiconductor laser. In this scheme, signal light injection into the laser will cause frequency shift of laser modes, as a result, the probe light into the laser can be switched between injection-locked and unlocked status, and its output power will be modulated. Theoretical analysis for this scheme is carried out by using a model to describe the dynamics of the injection-locked laser. By numerical simulation, the influence of laser bias current, laser length, injected signal power and signal frequency on the output performance of NOR logic gate is quantitatively analyzed.

Abstract:Using multiple importance sampling (MIS) technique, the optical communication system performance affected by polarization-mode dispersion (PMD) and polarization-dependent loss (PDL) is simulated numerically. The power penalties and system outage probabilities are obtained for optical communication systems with on-off keying (OOK) or differential phase shift keying (DPSK) modulation. The simulation results show that DPSK always performs better than OOK. When the system has moderate PDL (about 1.5 dB), it is necessary to compensate effectively the fiber PMD in order to enhance the system tolerance to the PMD and PDL. However, the efficiency of PMD compensation will degrade rapidly when the PMD of the whole optical link drops into the low value.

Abstract:The impacts of interband and intraband crosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.

Abstract:It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer (LDV).

Abstract:Dimensionally correct and directly traceable measurement is not feasible with conventional scanning tunneling microscopy (STMs) due to severe hysteresis and non-linearity of the commonly applied piezo tube scanners and the very short range.By integrating a custom made probing system based on tunneling current measurement into a commercially available and laser-interferometrically position controlled positioning system, an STM with a principal measuring range of 25 mm×25 mm×5 mm and traceable position measurement has been set-up and tested.

Abstract:To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.

Abstract:3D shape dynamic measurement is essential to the study of machine vision, hydromechanics, high-speed rotation, deformation of material, stress analysis, deformation in impact, explosion process and biomedicine. in recent years. In this paper,the results of our research, including the theoretical analysis, some feasible methods and relevant verifying experiment results, are compendiously reported. At present, these results have been used in our assembling instruments for 3D shape measurement of dynamic process.

Abstract:An electronic speckle shearing phase-shifting pattern interferometer (ESSPPI) based on Michelson interferometer was based in this paper. A rotatable mirror driven by a step motor in one of its reflective arm is used to generate an adjustable shearing and the mirror driven by piezoelectric transducer (PZT) in the other reflective arm was used to realize phaseshifting. In the experiments, the deformation of an aluminum plate with the same extern-force on different positions and different forces on the same position is measured. Meanwhile, the phase distribution and phase-unwrap image of the aluminum plate with the extern-force on its center position is obtained by the four-step phase-shifting method.

Abstract:Based on the first type of Rayleigh Sommerfeld diffraction formula, an imaging model of circular aperture-array structure digital sun sensor optical system is developed. Then a 6×6 circular aperture-array structure optical system is designed. The results of numerical simulation show that the optical system is designed well and is conformed to the requirements of miniaturization and high accuracy of sun sensor.

Abstract:A fast quarter-pixel motion estimation algorithm is proposed in this paper. The proposed algorithm based on mathematical models of the motion compensated prediction errors. Unlike conventional quarter-pixel accurate motion estimation algorithm,proposed algorithm can avoid fractional-pixel interpolation and subsequent fractional-pixel search after integer-precision motion estimation. Experiments show that the proposed algorithm greatly reduces the computational complexity of quarterpixel motion estimation, while keeping the nearly equal quality of the image.

Abstract:The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectively with single pixel width and the processing speed is high.

Abstract:A large number of applications in the before mentioned sense is reported in the literature. In this paper a special remark will be given to the application of 3D deformation measurements using only one illumination direction for the recording of the two holograms in the reference and the loaded state, and only one observation direction for the reconstruction.

Abstract:By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.

Abstract:The purpose of Optoelectronics Letters is rapid reporting new important results in the fields of photonics-optoelectronics in English to advance the international academic exchanges.

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Abstract:On the occasion of yet New Year start, we take this opportunity to wish our readers, authors, reviewers, the members