Abstract:In this paper,a series of boron doped microcrystalline hydrogenated silicon-germanium(p-μc-Si1-xGex:H)was deposited by very high frequency plasma-enhanced chemical vapor deposition(VHF-PECVD)from SiH4 and GeF4 mixtures.The effect of GeF4concentration on films'composition.structure and electrical properties was studied.The resuIts show tllat with the increase of GeF4 concentration,the Ge fraction x increases.The dark conductivity and crystalline volume fraction increase first,and then decrease.When the GC is 4%,p-μc-Si1-xGex:H matefiai with high conductivity,low activation energy(σ=1.68 S/cm,Eg=0.047 eV),high crystalline volume fraction (60%)and with an average transmission coefficient over the long wave region reaching 0.9 at the thickness of 72 am was achieved.The experimental results were discussed in detail.

Abstract:The requirements on the precision of dimensional metrology are especially stringent in the area of semiconductor manufacturing.This holds in particular for the measurement and control of the linewidths of the smallest structures on masks and silicon wafers and their corresponding reference metrology.In this paper we will describe the physical models and the reference instrumentation which were developed for photomask linewidth metrology at the PTB.It will be shown,how the results of the different methods can be used for comparative analyses.Application of these methods Will be demonsUated exemplarily on the basis of newly developed photomask linewidth standards.

Abstract:We will present some technologies and devices employed for the fabrication of tunable micro-optics.Tunable liquid lenses and lens arrays as well as polymer membrane-based mierolenses and scanning mirrors are of both academic and industrial interest in this area.

Abstract:A novel photothermal drive method was proposed.A novel photothermal micro-actuator (PTA) was developed with this method.We introduced the deflection mechanism of the asymmetric expansive arms with different widths.When a beam of infrared laser irradiates the arms,the different increase temperature and photothermal expansion controlled by the different rates of specific surface area cause a magnified lateral deflection.A prototyping micro-actuator of 1000μm length was manufactred by using an exchner laser micromachining system,and using polypropylene material.Experiments have been carried out to check the feasibility of deflection,with a laser diode (650nm) as the external power source to activate the micro-actuator.The results show that the aclliator can practically generate an obvious lateral deflection without considering the size or the location of the irradiated light spot strictly.The deflection stares of the micro-actuator conId be controlled remotely from O μm to 14.33 μm by changing the laser power from O mW to 10mW.This kind of novel PTA is quite simple and convenient for operation.It will be quite useful for the applications in the fields of micro/nano-technology and with large displacement/actuation force and remote controlling.

Abstract:In this paper,the multimode waveguide lengths and the output port locations of a SOI(silicon on insulator)material-based 1x4 MMI(multimode interference)optical splitter are optimized by means of FD-BPM (finite difference-beam propaga-tion method).An improved 1x4 MMI optical splitter is designed.Compared with an usual optical splitter,a smaller loss O.12dB and a better output port power uniforrnity 0.11dB are achieved for the optical signal transmission.

Abstract:A temperature window of single-walled carbon nanotubes(SWCNTs)growth has been studied by Raman spectroscopy.The results presented when temperature lowcr than 750℃,there were few SWCNTs formed,and when temperature higher than 900℃,mass amorphous carbons were formed in the SWCNTs bundles due to the serf-decomposition of CH4.The temperature window of SWCNTs efficiently growth is between 800 and 900℃,and the optimum growth temperature is about 850℃.These results were supported by transmission electron microscope images of samples formed under different temperature.The temperature window is important for large-scale production of SWCNTs by catalytic chemical vapor deposition method.

Abstract:In this letter,a kind of two-dimensional photonic crystal structure appficable to THz devices is designed,and how to form a microcavity in this structure is discussed.The primary properties of the resonant cavity are analyzed,in which plane wave expansion method is used to make the calculation and the simulation.We've studied the variation of the bandgap structure and resonant frequency in THz region by changing the parameters,such as lattice constant,dielectric constant contrast and idling factor.The research results provided theoretical support for manufacturing the THz devices and the application of THz system.

Abstract:A new method to obtain supemontinuum(SC)source for multiplex coherent anti-stokes Raman scattering(CARS)micros-copy is proposed.The nonlinear propagation in photonic-crystal fibers(PCF)of femtosecond pulse laser with central wavelength at 800.9 nm is studied with scalar wave theory.Based on the incident laser power and dispersion of PCF,super broadband source for multiplex CARS microscopy is designed.

Abstract:Based on the dual peak resonance of long-period fider grating(LPFG),a novel film sensor is presented.in which films sensitive to the surrounding gases are coated on the cladding of the fiber grating region,and the intervals of the dual peak resonant wavelengths change with the film refractive index.According to the coupled-mode theory,a triple-clad numerical model is developed to analyze the relation between the sensitivity S and the thin film optical parameters(the film thickness h3 and the refractive index n3and the fiber grating parameters (the grating period A and the coreindex modulation (o)).By using optimization method,the optimal film optical parameters and the grating structure parameters are obtained.Numerical simulation shows that the sensitivity of this scheme to refractive index of the films is predicted to be more than 10-7.The theomtic analysis provides straightforward foundation for the aetual highly sensitive fdm sensors.

Abstract:The triangular-lattice highly birefringent photonie crystal fibers(PCFs)with gradually increasing dmmeter of the air holes along radial axis are put forward.The medal birefringence,dispersion and confinement loss of the fundamental mode ale simulated by full vector Galerkin finite element method(FEM)with a perfectly matched layer(PML).The results show that this PCF can keep loW confinement loss when the rings of air holes are feW.When the wavelength is 1.55 pm.the birefringence,the confinement loss of quick-axis and sloW-axis are 1.365×10-3,0.017 dB/m and 0.051 dB/m,respectively.A new way is proposed to fabricate polarization-mainting fibers with high performance.

Abstract:Temperature sensitivity is greatly improved by taking the following three measures:proper long-period fiber grating(LPFG) whose strain coefficient of the core is larger than that of the cladding is employed.the LPFG is coated with a thin film of the material whose refractive index decreases with the temperature.and the sensor is encapsulated by metal material whose thermal expansion coefficient is large.By computer simulation,a measured temperature coefficient of 0.2375 nm/℃ and a temperature resolution less than 0.1 ℃ are obtained.

Abstract:To analyze the stability of nearly zero flattened dispersion,the dispersion deviations for three kinds of PCFs arc calculated when the hole diamcters deviate from their designed values.Numerical resuIts show that around the wavelength of 1.55μm,the dispersion deviations of both the PCF with three-fold symmetry core and the PCF with hexagonal lattice are much less than that of the PCF with different hole diameters in different rings.Therefore.the stabilities of nearly zero flattened dispersion of the first two kinds of PCFs are much better than that of the last one.Considering the confinement loss.the PCF with three-fold symmetry core is preferabk to practical USe.

Abstract:An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size,generations,crossover ratio and mutation ratio to genetic algorithm,and the optimization parameters of genetic algorithm were given.The relevant experimental system is constructed.The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasi-static FBG sensing system at transverse uniform press,the strain measurement with high-precision of O.91% can be realized

Abstract:Akind of white OLED with single luminescent layer was designed.in which mbrene was dopeal in Liq.The structure of the devices is ITO/PVK:TPD/Liq:Rubrene/Alq3/Al.The brightness of the devices comes to 3120 cd/m2(at a driving voltage of 25V),the CIE coordinates of the typical devices is(0.308,0.347),and the coordinates is very close to the white equi-energy point.The emitfing and luminescent characteristics of the devices Were discussed.

Abstract:In this paper, a series of boron doped microcrystalline hydrogenated silicon-germanium (p-μc-Si_1−xGe_x:H) was deposited by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) from SiH₄ and GeF₄ mixtures. The effect of GeF₄ concentration on films’ composition, structure and electrical properties was studied. The results show that with the increase of GeF₄ concentration, the Ge fraction x increases. The dark conductivity and crystalline volume fraction increase first, and then decrease. When the GC is 4%, p-μc-Si_1−xGe_x:H material with high conductivity, low activation energy (σ=1.68 S/cm, E _g= 0.047 eV), high crystalline volume fraction (60%) and with an average transmission coefficient over the long wave region reaching 0.9 at the thickness of 72 nm was achieved. The experimental results were discussed in detail. This work has been supported by National Basic Research Program of China (“973” Project, No.2006CB202602, 2006CB202603), the National Natural Science Foundation of China (No. 60437030), and the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the State Education Ministry.

Abstract:A three-sidewalls-prism holographic method has been provided for the fabrication of 3-D fcc-type polymeric photonic crystal using negative photoresist.Special fabrication treatment has been introduced to ensure the stability of the fabricated nanostructures.The scanning electronic microscopy (SEM) and the diffraction results testified the good dependability of the fabricared structures.The simulation of the partial band structure is in good agreement with the transmission and reflection spectra obtained by Fouricr transform infrared spectroscopy.

Abstract:ITO:Zr films were deposited on glass substrate by co-sputtering with an ITO target and a Zirconium target.Substrate temperature and oxygen flow rate have important influences on the properties of ITO:Zr films.ITO:Zr films show bettex crystalline strucmfe and lower surface roughhess.Better optical-electrical properties of the films cam be achieved at low substrate temperature.The certain oxygen flow rates worsen the electrical properties but can enhance the optical properties of ITO:Zr films.The vadation in optical band gap can be explained on the basis of Burstin-Moss effect.

Abstract:Today,micro-system technology and the development of new MEMS(Micro-Eleetro-Mechanical Systems)ate emerging rapidly.In order for this development to become a SUCCESS in the long run,measurement systems have to ensure product quality.Most often,MEMS have to be tested by means of functionality or destructive tests.One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities.We present a measurement system that could be used for these kinds of measurements.The system combines a fiber optical,miniaturized sensing probe with low-coherence intcrferometry,so that absolute distance measurements with nanometcr accuracy are possible.

Abstract:Geometrical features of micro-systems can be determined by either tactile or optical profiling techniques,which show different non-linear transfer characteristics.This has to be considered especially,if the instrumcnts operate close to their physical limitations.Depending on the specific measuring task either point-wise or areal optical measurement may be advantageous.Hence,examples for boIh approaches are discussed.Furthermore,systematic effects,which are related to the measuring principle have to be taken into account,e.g.if sharp edges or slopes ale present on the measuring object.As it is shown,for white-light interferometry these difficulties can be solved by a two-wavelength technique.

Abstract:A sapphire fiber thermal probe with Cr3 ion-doped end was grown using the laser heated pedestal method.The fluores-ccnce themal probe offers advantages of compact structure,high performance and the ability to sustain high temperature from the room temperature to 450℃.Based on the fast fourier transform(FFT),the fluorescence lifetime is obtained from the tangent function of the phase angle of the first non-zeroth item of FFT result.Compared with other traditional fitting methods,our method has advantages such as fast speed,high accuracy and being free from the influence of the base signal.The standard deviation of FFT method is about half of that of the Prony method and close to the one of the Marquardt method.In addition.since the FFT method is immunity to the background noise of the signal,the background noise analysis can be skipped.

Abstract:Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor. This work has been supported by National Natural Science Foundation of China (Grant No. 60377006) and the Optical Science and Technology Program of Science and Technology Committee of Shanghai (Grant No. 036105033).

Abstract:Waveguide multilayer optical card(WMOC)is a new kind of three-dimensional storage device.A method of fabricating the WMOC using the moMing techniqBe is introduced in this paper.The fabrication of WMOC mainly includes data writing with hot embossing method and multilayer bonding with PDMS material The structure of the WMOC is comisted with Polyearbonate (PC) as the core layer material and Polydimethylsiloxane (PDMS) as cladding layer.The experimental ICSUIts demonstrate that the molding fabrication method is leasible and effective.

Abstract:It is a key problem to accurately calculate beam spots'center of measuring the warp by using a collimated laser.A new method,namedd ouble geometrical center method(DGCM),is put forward for the first time.In this method,a plane wave perpendicularly irradiates an aperture stop,and a charge couple device(CCD) is employed to receive the diffraction-beam spots,then the geometrical centers of the first and the second diffraction-beam spots are calculated respectively,and their mean value is regarded as the center of datum beam.In face of such adverse instances as laser intension distributing defectively,part of the image being saturated.this method can still work well.What's mole,this method can detect whether an unacceptable error exits in the courses of image receiving,processing and calculating.The experimental results indicate the precision of this method is high.

Abstract:The effect of laser mierobeam trapping the bioparticles has been applied widely in the biology.However the micmInechanjsm of the acting that realizes the laser-microbeam trapping bioparticles is still lacking.In this paper,the act microehenism of the gradiant force of laser mierobeam for the bioparticles is analysed by means of quantum theory,The result accords with our experiment.

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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. The scope of Optoelectronics Letters is as follows:

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