Metal oxide semiconductor (MOS) device down-scaling is a powerful driving force for the evolution of microelectronics. The downsizing rate of metal oxide semiconductor field effect transistors (MOSFETs) is really marvelous. Silicon dioxide (SiO₂) has served as a perfect gate dielectric for the last four decades. Due to physical limitations, leakage current, high interface trap charge it now needs to be replaced with higher permittivity dielectric material. Keeping the motivation for the search of high-k materials, extensive studies have been carried out on several metal oxides, such as ZrO₂, Ta₂O₅, TiO₂, Al₂O₃ and HfO₂ for the replacement of SiO₂. The high dielectric constant (k) of titanium dioxide (TiO₂) will open multifaceted prospects for the use of this material in microelectronic devices. In this paper, a comparative study of various deposition methods for fabrication of thin TiO₂ films has been presented. This work uses a combination of simulation results, experimental data and critical analysis of published data. Further, an experiment using sol-gel method has been carried out to deposit thin films of TiO₂. It has been characterized and compared with the earlier reported fabrication methods. The X-ray diffraction analyses and Raman spectra indicate the presence of anatase TiO₂ phase in the film. The dielectric constant as calculated using capacitance-voltage (C-V) analysis was found to be 23. The refractive index of the film was 2.43. The TiO₂ films studied for microelectronic applications and present acceptable properties such as low leakage current density of 1.0×10^-5 A/cm at 1 V and band gap of 3.6 eV. The leakage current has been found to be dominant by the Schottky emission at lower electric field, while Flower-Nordheim (F-N) tunneling occurs at higher biasing voltages.

Electrically tunable silicon (Si) plasmonic phase modulators with nano-scale optical confinement are presented and analyzed in this study. The modulation is realized based on two mechanisms: free carrier plasma dispersion effect in Si and high electro-optic effect in polymer. The phase modulators can be found potential applications in optical telecommunication and interconnect.

The influence of V/III ratio on the formation of quantum dots (QDs) grown by metal-organic chemical vapor deposition (MOCVD) is investigated by atomic force microscopy (AFM) and photoluminescence (PL) measurements. As V/III ratio increases, the density of QDs decreases accompanied by the transition of QD size distribution from bimodal (at V/III= 9) to single-modal (at V/III= 15), and then to bimodal (at V/III= 25) again, which is attributed to the change of the indium-species migration length at different V/III ratios. There are PL spectrum redshifts and the PL peak intensity decreases as V/III ratio increases.

A Poly (3, 4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS)/carbon conductive paste was prepared and coated on a conducting FTO glass to construct counter electrode for polymer heterojunction dye-sensitized solar cells (DSSCs). The surface morphology, conductivity, sheet resistance, redox properties and photoelectric properties of carbon electrode were observed respectively by scanning electron microscopy, four-probe tester and CHI660D electrochemical measurement system. The experimental results showed that DSSCs had the best photoelectric properties for PEDOT:PSS/carbon counter electrode annealing at 80°C in vacuum conditions. Using [6, 6]-phenyl-C₆₁-butyric acid methyl ester (PCBM)/poly (3-hexylthiophene) (P3HT) heterojunction to replace I3-/I- redox electrolyte, the overall energy conversion efficiency of the DSSCs with barrier layer reached 4.11% under irradiation of a simulated solar light with a intensity of 100 mW·cm^-1 (AM 1.5), which is higher 20% than that of the DSSCs with Pt counter electrode (3.42%). The excellent photoelectric properties, simple preparation procedure and low cost allow the PEDOT:PSS/carbon electrode to be a credible alternative used in DSSCs.

Silicon nanowires (SiNWs) with tens of micrometer in length have been synthesized and modified with Ag nanoparticles, which were confirmed by X-ray diffractometer (XRD), scanning electron microscopy and transmission electron microscopy. The Ag/Si nanostructure was employed to detect inorganic ions SO42- via surface-enhanced Raman scattering (SERS) with strong signals at low concentrations of 1×10^-9 mol/L. This ultrasensitive method might be applied in other fields.

Europium pentafluoropropionate 1,10-phenanthroline complex, Eu(C₂F₅COO)₃·Phen (Phen= 1,10-phenanthroline), were synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TA). At the same time, its silica glass was synthesized by in situ processes. The excitation spectra of the complex demonstrate that the energy collected by “antenna ligands” was transferred to Eu³⁺ ions efficiently. The room-temperature PL spectra of the complexes are composed of the typical Eu³⁺ ions red emission, due to transitions between ⁵D₀→⁷F_{J(J = 0→4)}. The decomposition temperature of the complex was 290°C, which indicates the host complex is quite stable to heat. Then the affection of anneal temperatures on PL properties of SiO₂ glass were studied. The PL intensity of the SiO₂ glass annealed at 160°C was higher than other annealed temperatures for 24 h in air.

By numerically solving Maxwell’s equations and rate equations, a comprehensive calculation on spectrum intensity and spectral widths of three localized modes via different pumping rates in one-dimensional (1D) disordered medium is investigated, in which pumping rate is described by a time function with duration of 80 fs. The spectral intensities varying with the peak value of femtosecond (fs) pumping pulse are calculated in the same disordered medium, and the calculated spectral intensities are compared with those with fixed pumping (simulation time is 6 ps). These results show that excited modes with fs pulse pumping rates are only slightly different from those with fixed pumping (picosecond (ps) pulse), which suggests the excited modes largely depend on the medium rather than the pumping rate at least for those of which pumping rates are fs and ps. At last, lifetimes of three excited modes are calculated. It is found that there is a certain corresponding relation between the mode’s lifetime and its threshold-pumping rate, which is the longer lifetime with lower threshold.

With the development of laser technology, laser application technology increasingly plays a leading role in the field of industry. High power laser products and their safety requirements are attracting more attention. In laser industrial applications, laser beam quality and the system of laser beam propagation and focusing are greatly ignored. Furthermore, the basic safety standards for laser products have been neither widely publicized nor strictly enforced because of rapid development. This paper examines the underlying relationship between laser beam quality and laser manufacturing, and makes a comparison among different laser systems. It is also shown how the laser safety standards could be better understood and laser beam quality standard is advocated that directly relates to a mission requirement.

In order to process underwater imaging to the best possible level, an imaging model based on beam propagation was established. The presented model included not only the laser beam propagation affected by absorption and scattering, but also the effects of underwater turbulence and the diffraction limit of sensors. By this model approximately quantified optical transfer functions (OTFs) were studied. Thus, under this framework, the approaches of image enhancement, restoration and super-resolution reconstruction (SRR) can be extended by incorporating underwater optical properties based on OTF or point spread function (PSF) of the imaging system. Experimental results proved that the imaging range and the image quality can be effectively enhanced, which are critical in underwater imaging or detecting.

Broadband parametric upconverted conical emission (CE) has been investigated in an isotropic amorphous medium pumped by femtosecond laser pulses, which covers a broad range from 470 to 630 nm. Three theoretical models were analyzed to interpret the angular beam of CE. The CE spectra and their angular positions have been experimentally measured, which can be explained well by nonlinear X-wave model and Cerenkov type phase matching model rather than four-wave mixing (FWM) model.

A speed measurement system utilizing a stable single frequency Q-switched Tm:YAG laser was presented in this study. The maximum pulse energy of the laser was 2.38 mJ with the pulse repetition rate of 100 Hz. Using the speed measurement system, the revolving speed of a rotating target could be measured by optical heterodyne detection technique and the maximum measurement error was 0.68 m/s.

Photonic crystal fibers (PCFs) present a wavelength-scale periodic microstructure along their length. Their core and two-dimensional photonic crystal might be based on varied geometries and materials, allowing supercontinuum (SC) generation due to nonlinear effects in an extremely large wavelength range. In this paper we have reviewed PCFs utilized for SC generation. Fiber fabrication for SC generation is present. Spectral broadening mechanisms are also described in brief. Particular attention is as well as paid to PCFs including uniform PCFs, cascaded fibers, tapered fibers and PCFs with special material doped, which are commonly used to generate SC.

In this paper, a new simple structure of index-guiding photonic crystal fiber (PCF) is designed and presented. In this PCF, dispersion, confinement loss, and effective mode area characteristics are investigated in the second communication window (1.55 μm). Since 1.55 μm wavelength is widely used in optical communication systems, we try to optimize the PCF characteristics in this wavelength by designing an index-guiding PCF and three versions of optimized PCF. The results show that the dispersion is obtained very close to zero around 4.6×10^-4 ps/(nm·km). Also, the confinement loss is 2.303×10^-6 dB/km and effective mode area is as small as 2.6 μm².

A high power all-fiber single-mode 1091 nm laser is constructed in master oscillator power amplifier (MOPA) configuration. The home-made seed source is an Yb³⁺-doped fiber ring laser with 22.5 mW maximal output power. A two-stage pre-amplification configuration is employed to boost seed power to 3 W. The ultimate output power of the main amplification stage is 62.5 W, corresponding to an optical-to-optical conversion efficiency of 78.1%. No residual pump light or amplified spontaneous emission (ASE) is observed under maximal output power. Because of the using of fiber Brag grating (FBG) to select frequency in seed laser, the full width at half maximum (FWHM) linewidth of output light is narrower than 0.1 nm.

The axial strain sensitivity of long period fiber grating (LPFG) is analyzed by new transfer matrix method. The new transfer matrix method can be used to analyze the modes coupling between the core mode and multiple cladding modes. Compared with the previous method used, such as solving the coupled mode equation by the fourth order adaptive step size Runge-Kutta algorithm, the new transfer matrix method (TMM) has a faster calculation speed. Theoretical results are excellent agreement with the method of solving the coupled mode equation (SCME).

Infrared focal plane arrays (IRFPAs) usually contain many defective pixels. These defective pixels have to be corrected because those can significantly impair the performance of infrared image of IRFPAs. As is known to all, infrared image acquisition and analysis based on Matlab can be helpful to identify and correct defective pixels. In this paper, we proposed a novel method to identify and correct defective pixels. In the phase of identification, the defective pixels could be identified by the algorithms combined with median filtering algorithm and improved standard deviation algorithm. In the phase of correction, proportion-spatial defective pixel replacement (PSDPR) algorithm was introduced to replace the defective pixels, and this method reduced the difficulty of replacement originating from the clustering phenomenon of defective pixels. In addition, an experiment of verification was done, and showed the proposed scheme worked effectively.

During thermal imaging, it is vital importance to obtain high-performance images that non-uniformity noise in infrared focal plane array (IRFPA) should be eliminatined and the imaging spatial resolution should be improved as far as possible. Processing algorithms related to both of them have been hot topics, and attracted more and more attention of researchers. Considering that both high-resolution restoration algorithm of image sequences and scene-based non-uniformity correction (NUC) algorithm require multi-frame image sequences of target scene with micro-displacement, an integrated processing algorithm of high-resolution image reconstruction and NUC of infrared image sequences based on regularized maximum a posteriori (MAP) is proposed. Results of simulated and experimental thermal image suggested that this algorithm can suppress random noise and eliminate non-uniformity noise effectively, and high-resolution thermal imaging can be achieved.

The absorption spectra from 0.2 to 1.7 THz of five water-acetone mixtures, whose concentrations are 0%, 25%, 50%, 75%, and 100%, has been investigated by THz time-domain spectroscopy (THz-TDS). The result indicates that of acetone solutions with different concentrations have different absorption for THz radiation, which is analyzed and attributed to the variation of the hydrogen bond. Furthermore, we also find the absorption of the water-acetone mixture almost linearly increases with the increase of water concentration in the THz range.

We propose an approach to generating 6-channel polarity-inverted ultra-wideband (UWB) doublets by utilizing the parallel fiber-optical parametric amplifier (FOPA) configuration. The pulse-splitting effect in a highly nonlinear fiber (HNLF) is exploited to generate the double-overshoot and the double-undershoot, which are the basic components required to form a UWB pulse. Under the circumstances of different relative time advance/delays (RTADs) and different initial Gaussian pulse durations, the key parameters, including center frequency (Fc), 10-dB bandwidth (BW_10dB) and fractional bandwidth (FBW) for a UWB doublet are systematically investigated, eventually proved in line with the U. S. Federal Communications Commission (FCC) regulation.

The Al-AlN granular film was proposed as a cathode emitter of surface-conduction electron-emission display (SED) and the effect of Al-AlN granular films’ resistivity on electroforming in experiment and simulation methods was studied. Electroforming could be successfully completed with appropriate Al-AlN granular film resistivity between 1.98 and 15.10 mΩ·cm, and the corresponding turn-on voltage of electroforming increased from 6.2 to 10.5 V with the resistivity increasing. In addition, a temperature profile on Al-AlN emitter was simulated and the temperature decreased from middle to two sides, which were corresponding to surface morphology of Al-AlN emitter after electroforming.

Electrorheological (ER) finishing utilizes the flow of electrically stiffened abrasive fluid through a preset converging gap formed by the work-piece surface and a moving tool. An ER finishing tool characterized by cathode integrated with anode together is proposed, whose electric field distribution is finite-element-analyzed (FEA) and is useful to finish both conductive work-piece and non-conductive ones. Experiments were performed to finish a K9 glass by this tool. After 30 minutes polishing, the surface roughness was reduced from 8.46 to 2.53 nm Ra which is better than previously reported 2.9 nm. The result verified the validity of the integrated-electrodes tool for non-conductive optical glasses.