线性共蒸法制备非均匀膜的误差特性模拟分析

对双源线性共蒸法制备的非均匀薄膜折射率分布与光学特性的关系作了探讨，并与均匀介质膜的光学特性作了对比；从折射率正变和负变两个方面．讨论了混合介质膜折射率不同变化规律对光学性能带来的影响；讨论了厚度误差和折射率极值误差对非均匀膜光学性能的影响。结果发现：折射率变化规律误差主要对非均匀膜的应用波段范围产生影响，而膜层厚度误差和折射率极值误差超过一定值时，将对薄膜光学特性产生重要影响。

渐变折射率薄膜的分层评价探讨

首先阐述了将渐变折射率薄膜细分为多层均匀薄膜的分层介质理论，接着给出了一种获得最佳分层数目的分层评价方法，最后以线性变化渐变折射率薄膜为例说明了如何优化获得渐变折射率薄膜的分层数目．研究发现：渐变折射率薄膜的分层数目与薄膜的厚度和薄膜的折射率变化快慢有关，在一定的折射率变化范围内，渐变折射率薄膜的分层数目随着薄膜厚度的增加先减小后增大．

Relação entre periodontite e síndrome metabólica

Os objetivos desse estudo foram: (1) avaliar se o diagnóstico da periodontite crônica pode auxiliar na identificação de pacientes com síndrome metabólica, e (2) verificar o efeito da terapia periodontal não-cirúrgica sobre os componentes utilizados para o diagnóstico da síndrome metabólica nos pacientes com periodontite crônica. No estudo 1 foram avaliados 33 pacientes com periodontitecrônica (idade média 50,3, DP 7,9 anos) e 36 pacientes controles (gengivite/saudável) (idade média 39,7, DP 10,3 anos), sem diagnóstico de síndrome metabólica. Os pacientes foram avaliados clinica e laboratorialmente para verificar possível associação entre a presença de periodontite e diagnóstico precoce de síndrome metabólica. Os parâmetros clínicos usados foram: Índice de placa visível (IPV), índice de sangramento gengival (ISG), profundidade de bolsa à sondagem (PBS) e nível de inserção clínica (NIC). Os níveis séricos de proteína C Reativa (PCR), glicemia em jejum, colesterol e triglicerídeos foram analisados. Também foram verificados peso, altura, circunferência da cintura, Índice de Massa Corporal (IMC) e pressão arterial. No estudo 2, os pacientes com periodontite crônica foram tratados através da terapia periodontal não-cirúrgica e reavaliados 90 dias após tratamentopara nova avaliação de exames clínicos (PBS, NI, IPV, ISG). Os dados depeso, altura, circunferência da cintura, IMC e pressão arterial e as avaliações séricas foram repetidas e comparadas aos do dia 0. No estudo 1 foi constatado que o nível sérico de glicose e o número de itens da síndrome metabólica presentes foram estatisticamente maiores no grupo teste do que no grupo controle. No estudo 2, os níveis de glicose, colesterol, LDL, PCR e número de itens da síndrome metabólica presentes reduziram significantemente e o HDL aumentou significantemente após a terapia periodontal não-cirúrgica. Assim, podemos concluir que o diagnóstico de periodontite crônica aumenta a chance de diagnóstico de síndrome metabólica e que o tratamento periodontal foi eficaz em melhorar alguns componentes da síndrome metabólica.

Prevalência do polimorfismo -1031 T>C do gene TNFA em um grupo de diabéticos tipo I e sua relação com a periodontite severa

Diabetes mellitus e doenças periodontais são altamente prevalentes na população mundial. Doenças periodontais (DPs) compreendem um grupo de condições crônicas inflamatórias induzidas por microorganismos que levam à inflamação gengival, à destruição tecidual periodontal e à perda óssea alveolar. Diabetes mellitus (DM) é o termo utilizado para descrever um grupo de desordens metabólicas associadas à intolerância à glicose e ao metabolismo inadequado de carboidratos. Uma vez que DPs poderiam agir de forma similar a outros estados infecciosos sistêmicos, aumentando a severidade do diabetes, uma possível relação entre ambas tem sido considerada em todo o mundo. Polimorfismos genéticos de um único nucleotídeo (SNPs) têm sido estudados em diversas doenças. Nas periodontites, acredita-se que possam estar envolvidos na exacerbação da resposta inflamatória frente ao desafio bacteriano, modificando a susceptibilidade do hospedeiro. Neste estudo, a prevalência de periodontite foi avaliada em portadores de diabetes mellitus tipo I. Posteriormente, o SNP localizado na região promotora do gene TNFA (-1031T>C) foi analisado e sua importância para a doença periodontal destrutiva foi avaliada. O grupo teste foi constituído por diabéticos tipo I (DGT, n=113) enquanto o grupo controle por indivíduos não diabéticos (ND, n=73). Para as análises dos polimorfismos genéticos, um subgrupo foi retirado do grupo teste (DG, n=58) e comparado ao grupo ND. Os seguintes parâmetros clínicos e demográficos foram avaliados: percentual de sítios com profundidade de bolsa  6,0 mm (%PBS6,0 mm); índice gengival (IG); perda óssea radiográfica (POR); fumo; duração do diabetes ; idade; índice de massa corpórea (IMC), n de internações e n de dentes presentes. Amostras de sangue e/ou esfregaço bucal foram colhidas de 58 pacientes do grupo teste e de 73 controles. Após a extração do DNA genômico e amplificação da região genômica de interesse por PCR (Polymerase Chain Reaction), o polimorfismo TNFA 1031T>C foi analisado por BbsI RFLP (Restriction Fragment Length Polymorphism). A análise dos produtos de digestão foi feita por eletroforese em gel de poliacrilamida 8%. A análise estatística das freqüências alélica e genotípica juntamente com os dados clínicos e epidemiológicos entre os 2 grupos foi feita através do teste do Mann-Whitney e do Qui-quadrado. Os grupos de estudo obedecem ao princípio de Hardy-Weinberg. No grupo ND, as seguintes freqüências genotípicas foram encontradas: 78,1% (T/T); 20,5% (T/C) e 1,4% (C/C) enquanto no grupo D foram: 42,4%(T/T); 37,3% (T/C) e 20,3% (C/C). A frequência do alelo T no grupo diabético (D) foi de 0,610 ao passo que no grupo ND foi de 0,883. Não foi possível encontrar uma relação entre o polimorfismo -1031 T>C do gene TNFA e a presença de periodontite em diabéticos tipo I. Entretanto, o polimorfismo estudado se mostrou significativamente relacionado (p<0,0001 e OR= 4.85 95%IC 2,271-10,338) à presença do diabetes tipo I.

Optical phase modulation using a hybrid carbon nanotube-liquid-crystal nanophotonic device.

The carbon nanotube-liquid-crystal (CNT-LC) nanophotonic device is a class of device based on the hybrid combination of a sparse array of multiwall carbon nanotube electrodes grown on a silicon surface in a liquid-crystal cell. The multiwall carbon nanotubes act as individual electrode sites that spawn an electric-field profile, dictating the refractive index profile within the liquid crystal and hence creating a series of graded index profiles, which form various optical elements such as a simple microlens array. We present the refractive index and therefore phase modulation capabilities of a CNT-LC nanophotonic device with experimental results as well as computer modeling and potential applications.

Survey of biosystematic and sexual reproductive physiology in Holothuroidea on Hormozgan Province

Sea cucumbers belong to phylum Echinodermata, order Holothuroidea are an abundant and diverse group of Invertebrates, with over 1400 species occuring from the intertidal to the deepest oceanic trenches. Sea cucumbers are important components of the food chain in temperate and coral reef ecosystems and they play an important role as deposite feeders and suspension feeders. Rapid decline in populations may have serious consequences for the survival of other species that are part of the same complex food web,as the eggs, larve and juveniles constitute an important food source for the other marine species including crustaceans, fish and mollusks. In addition sea cucumbers are often called the earthworms of the sea, because they are responsible for the extensive shifting and mixing of the substrate, and recycling of detrital matter. Sea cucumbers consume and grind sediment and organic material into finer particles , turning over the top layers of sediment in lagoons , reefs and other habitats and allowing the penetration of oxygen. While the taxonomy of the holothurian families is generally well known , the distinction of similar species is difficult. There are relatively few holothurian taxonomist.Most sea cucumber species can be identified by Holothurin taxonomists by using the calcareous skeletal ossicles found in the body wall. In this study , at first a sea cucumber from Kish island in Persian gulf has recognized. Individuals collected from west and east extend far away into north and south of coral reefs by diving. I have checked them morphologically and anatomically.Then with key to the orders of the Holothuroidea, They belong to the Aspidochirotida with key to the families of Aspidochirotida, they were in Stichopodidae families and with key to the genus of Stchopodidae, they were Stichopus. Then ossicles were extracted at National Museum of Natural History, by Dr David Pawson. The ossicles were measured on a transect across a slide prepared from the mid-dorsal region of each specimen.The one we have in the shallow waters of Kish island, is Stichopus hermanni, a massive holothurian, body broad, considerably flattened ventraly ,the dorsal side slightly arched and the lateral sides almost vertical; body wall fairy thick and soft ; mouth subterminal; anus central; tentacles usually 20 in number of length and leaf shaped. Numerous ossicles consisting of table with large discs having usually 7 to 15 peripheral holes, but often irregular or incomplete and spire of moderate height ending in a group of spinelets, rosettes of variable development, and c-shaped rods. Color (exept papillae)partly remained after preservation in alcohol which is found at the depth of 4 to 8 meters, on coral reef. Furthermore, the sexual reproductive cycle was described using standard methods. Gonads were removed and transferred to Bouin's fixative for four weeks and then processed according to standard embedding technique. To prevent the loss of tubule contents during embedding, the tubule sections, were cut well beyond the segment selected for sectioning. For each individual, six sections, each section with 5µm diameter by microtome were cut from tubules. These sections were first placed on gelatin coated slides (the gelatin was heated to 42°c) and then transferred to the oven at 37°c for one hour. This technique usually prevents the fragil tubules from breaking and the loss of gametes. The slides were stained with Eosin and Hematoxylin, and good resolution of the various cell types achieved.A second series of slides was stained with the Periodic Acid Schiff(PAS) to identify polysaccharides(glycogen). Monthly sampling was occurred.The sexual reproductive cycle was defined through the combined use of these criteria: Monthly percentages of the gonad stages for each sex, the monthly gonad index (GI) , given as the ratio of the wet gonad weight (G) to the dray weight (DW)and the monthly percentage of individuals that undetermined sex. The gonad consists of two tufts of tubules on which saccules develop. Gonadal development was classified into five stages: post spawning, recovery, growth, advanced growth, and mature stage that were adapted from the earlier studies of holothurians. Histological preparations showed that the sex of larger individuals could be identified by the presence of oogonia and young oocytes in females, and spermatogonic stages in males.The mean diameter of the tubules and gonadal mass follow annual cycles, increasing from late winter through spring, and dropping abruptly after spawning in the summer. Gametogenesis is generally a prolongate process and begins in March. By summer the ovarian tubules contain oocytes with diameter of 120-240 pm and the testicular tubules contain an abundance of spermatozoa (diameter 5-6 gm ).Following spawning the predominant activity within the spent tubules is phagocytosis of the residual gamets.The active phase of gametogenesis (March to July), coincides with an increasing photoperiod regim, and an accelerated gametogenesis occurs in July when temperature is high. Throughout the year, the gonad of Stichopus hermanni is larger in males than in females, and this is due to the number of tubules in the testis rather than to tubules length or diameter.

Mode division multiplexing over 2km of OM2 fibre using rotationally optimized mode excitation with fibre coupler demultiplexer

A Spatial Light Modulator and a non-specialized multimode coupler are used together to provide sufficient channel isolation and modal bandwidth for 2x12.5Gbps NRZ over 2km of standard graded-index multimode fibre without DSP. © 2012 IEEE.

GaSb based midinfrared equilateral-triangle-resonator semiconductor lasers

Theoretical calculations of the mode characteristics of an equilateral-triangle resonator (ETR) with a 10 mu m cavity side length show that the fundamental mode, with longitudinal mode index of 25, has a wavelength of 2.185 mu m and a longitudinal mode separation of 100 nm. This mode has a quality factor (similar to 2x10(5)) that is much larger than the first (similar to 5x10(4)) and second (similar to 3x10(4)) order modes, indicating that single fundamental mode lasing should be accessible over a broad wavelength tuning range. An electrically injected ETR based on this design is fabricated from an InGaAsSb/AlGaAsSb/GaSb, graded-index separate-confinement heterostructure, laser diode wafer with a 2.1 mu m emission wavelength. This device achieved single mode, continuous wave operation at 77 K with a threshold current of 0.5 mA and a single mode wavelength tuning range of 3.25 nm, which is accomplished by varying the injection current from 0.5 to 6.0 mA. (C) 2008 American Vacuum Society.

Accurate mode analysis of ultraviolet-written channel waveguides

The transfer matrix method combined with the effective index method is adopted to model the silica-based channel waveguide patterned by UV writing. The effective indexes of the graded index channel waveguides with different dimension are calculated. The maximal error of the effective index is less than 3 x 10(-5). By this method, the number of the guided mode and the dimension range to guide certain modes can be obtained easily. Finally, the dimension range to guide a single mode is presented. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

Effect of rapid thermal annealing on electron emission and DX centers in strained InGaAs/GaAs single quantum well laser diodes

Thermal processing of strained In0.2Ga0.8As/GaAs graded-index separate confinement heterostructure single quantum well laser diodes grown by molecular beam epitaxy is investigated. It is found that rapid thermal annealing can improve the 77K photoluminescence efficiency and electron emission from the active layer, due to the removal of nonradiative centers from the InGaAs/GaAs interface. Because of the interdiffusion of Al and Ga atoms, rapid thermal annealing increases simultaneously the density of DX centers in the AlGaAs graded layer. The current stressing experiments of postgrowth and annealed laser diodes are indicative of a corresponding increase in the concentration of DX centers, suggesting that DX centers may be responsible for the degradation of laser diode performance.

A novel 1.3-mu m high T-0 AlGaInAs/InP strained-compensated multi-quantum well complex-coupled distributed feedback laser diode

A 1.3-mu m AlGaInAs/InP buried heterostructure (BH) stripe distributed feedback laser with a novel AlInAs/InP complex-coupled grating grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) is proposed and demonstrated. A high characteristic temperature (T-0 = 90K between 20-80 degrees C) and temperature-insensitive slope efficiency (0.25 dB drop from 20 to 80 degrees C) in 1.3 mu m AlGaInAs/InP DFB lasers was obtained by introducing AI(Ga)InAs graded-index separate-confinement heterostructure (GRINSCH) layers and a strained-compensated (SC) multi-quantum well (MQW).

An analysis and simulation about conditioned launch for very short reach (VSR-4)

VSR4 links use graded index multimode fibers (GIMMFs) as the transmission medium with operation wavelength 850nm. For cost reasons, VCSEL has been selected as the optical source to VSR4. The minimum bandwidth specification for 62.5um GIMMF in VSR4 is only 400 MHz(.)km for over-filled-launch (OFL) condition. The distance of 300 meters is limited over transmission rates of 1.25Gbit/s on the basis of this specification. In order to overcome the OFL bandwidth limit by selective excitation of a limited number of modes, conditioned launch technique is investigated. In this paper, based on a comprehensive dispersion theory of GIMMF, a model is built to simulate the transmission of optical signal in GIMMFs and a comparison between OFL and conditioned launch is analyzed. The result can be the guidelines for the best choice of techniques for various LAN and interconnect systems also.

Single-mode holey vertical-cavity surface-emitting laser with ultra-narrow beam divergence

We demonstrated oxide-confined 850-nm vertical-cavity surface-emitting lasers (VCSELs) with a two-dimensional petal-shaped holey structure composed of several annular-sector-shaped holes. Four types of devices with different hole numbers were designed and fabricated. The measured results showed that the larger hole number was beneficial to purifying the lasing mode, and realizing the single-mode operation. The side mode suppression ratio (SMSR) exceeded 30 dB throughout the entire drive current. Mode selective loss mechanism was used to explain the single-mode characteristic. The single-mode devices possessed good beam profiles, and the lowest divergence angle was as narrow as 3.2 degrees (full width at half maximum), attributed to the graded index profile and the shallow etching in the top distributed Bragg reflector (DBR).

808 nm high-power laser grown by MBE through the control of Be diffusion and use of superlattice

808 nm high-power laser diodes are gown by MBE. In the laser structure, the combination of Si-doped GRIN (graded-index) region adjacent to n-AlGaAs cladding layer with reduced Be doping concentration near the active region has been used to diminish Be diffusion and oxygen incorporation. As compared with the laser structure which has undoped GRIN region and uniform doping concentration for Si and Be, respectively, in the cladding layers, the slope efficiency has increased by about 8%. Typical threshold current density of 300 A/cm(2) and the minimum threshold current density of 220 A/cm(2) for lasers with 500 mu m cavity length are obtained. A high slope efficiency of 1.3 W/A for coated lasers with 1000 mu m cavity length is also demonstrated, Recorded CW output power at room temperature has reached 2.3 W.

Deep centers in AlGaAs/GaAs GRIN-SCH SQW laser structures grown by MBE and MOCVD

The deep centers in AlGaAs/GaAs graded index-separate confinement heterostructure single quantum well (GRIN-SCHSQW) laser structures grown by MBE and MOCVD have been investigated using deep level transient spectroscopy (DLTS) technique, The majority and minority carrier DLTS spectra show that the deep (hole and electron) traps (Hi and E3), having large capture cross sections and concentrations, are observed in the graded n-AlxGa1-xAs layer of laser structures in addition to the well-known DX centers. For laser structures grown by MBE, the deep hole trap H1 and the deep electron trap E3 may be spatially localized in the interface regions of discontinuous variation Al mole fraction of the n-AlxGa1-xAs layer with x = 0.20-0.43. For laser structures grown by MOCVD, the deep electron trap E3 may be spatially localized in the n-AlxGa1-xAs layer with x = 0.18-0.30, and the DX center may be spatially localized in the interface regions of discontinuous variation Al mole fraction of the AlxGa1-xAs layer with x = 0.22-0.30.