Photonics and Optoelectronics

1-8

Authors: Patrícia T. Pires, João C. Ferreira, Álvaro F. Azevedo, Sofia Arantes-Oliveira, Walter R. Dias, Paulo R. Melo

To evaluate Shear Bond Strength (SBS) values of different dental adhesives on Er:YAG laser prepared enamel and bur prepared enamel, one hundred and fifty bovine incisors were randomly assigned to SBS tests on enamel (n=15) in ten different groups. Groups 1 to 5 were prepared with Er:YAG laser. Groups 6 to 10 were mechanical prepared. Followed by: Group 1 and 6 – 37% phosphoric acid (PA) + ExciTE®; Group 2 and 7 – AdheSE®; Group 3 and 8 – FuturaBond® NR; Group 4 and 9 – ExciTE®; Group 5 and 10 – Xeno® V. After the adhesive systems samples were subjected to thermal cycling, SBS were performed in an universal testing machine at 5mm/min. Data were treated with two-way ANOVA, and post-hoc test (Student knewman keuls) (p<0,05). Chi-squared statistical tests were used to evaluate the type of fractures. Mean SBS values were Group 1– 47,17+/-6,25MPa; Group 2–29,10+/-5,21MPa; Group 3–23,32+/ -5,93MPa; Group 4 - 32,56+/-6,36MPa; Group 5– 24,43+/-6,76 MPa; Group 6- 26,12+/-6,32 MPa; Group 7– 14,77+/-3,47MPa, Group 8– 21,03+/-7,44MPa, Group 9– 3,25+/-2,91MPa; Group 10– 16,38+/-7,64 MPa. Statistical analysis of the data revealed that different preparation methods yielded significantly different shear bond strengths. Er:YAG laser preparation of enamel yielded higher bond strengths compared with traditional preparation.

15-25

Authors: Eldar N. Kurtaliev, Negmat Nizomov, Gairat Khodjayev

Spectral-fluorescent characteristics of styrylcyanine dye Sbt ((E)-2-(4-(dimethylamino) styryl)-3-methylbenzo [d] thiazol-3-ium iodide) and its derivatives in aqueous solutions with and without the presence of bovine serum albumin (BSA) were studied. In the presence of BSA for all studied dyes in the absorption spectra, we observed an increase in the absorption intensity, a small broadening, and a new band of the shorter wavelengths with λmax=412 nm. The intensity of the fluorescence emission of the baseband of the studied dyes in the presence of BSA increased from 1.1 to 4.6 times. The binding constant (K) and the number of binding sites (N) of the studied dyes with BSA were determined. The dependence of the binding constant with BSA on the dipole moment of the dye molecules was determined, which indicated that besides electrostatic attraction forces, hydrophobic interactions are significant between styrylcya¬nine dyes with BSA molecules. It was demonstrated that the aggregation of dyes influences the interactions of dyes with BSA.

37-50

Authors: Samir Sahu, Shantanu Dhar

Nonlinear material based all-optical switching mechanism is utilized here to develop the all-optical arithmetic operation scheme. Analog optical signals are converted to the corresponding digital signals by optical tree architectures. First a four bit arithmetic unit has been accessed which is elevated to a higher bit arithmetic unit in course. These circuits can execute innumerable arithmetic operations and remarkably, as they are all-optical and fully parallel in nature. These all-optical arithmetic units can gear up to the highest capability of optical performance in high-speed all-optical computers.

59-65

Authors: Zhejno I. Zhejnov, Jordan R. Urumov

In the article, a model of analysis and an algorithm for calculation of the group velocity dispersion and the losses of light, spreading in a Bragg optical fiber, are proposed. A mathematical model, based on the method of the geometrics optics is included. The influence of the fiber clad dielectric properties on the light propagation is taken into account. A comparison of the dispersion and the bandwidth of fibers with different number layers for low modes are made. Examples of Bragg fibers with different optical properties and attenuation are shown. Finally, advantages of the Bragg fiber, observed on the diagrams of attenuation, dispersion and bandwidth, are listed.

70-73

Authors: Pang Ming, Yuan Xiaoyan, Xie Zhimin, Hu Dingyun, Qiang Hui

Exploring experiments of laser thermal shock piston were conducted. The transient temperature of the piston was measured by high-resolution CCD cameras. Temperature of piston can be controlled by temperature-controlled method or time-controlled method. Results show the average temperature of thermal cycles can be improved by increasing heat duration time. There are different temperature response for piston with different preheat temperature in the same laser parameters.

85-95

Authors: M. A. Shams El-Din, H. H. Wahba, C. Wochnowski, F. Vollertsen

In this paper, a temperature controlled UV-laser lithographic method for the fabrication of integrated-optical polymeric waveguides is presented. The fabricated integrated-optical polymeric waveguides are examined at different processing temperatures. The influence of the temperature on the refractive index depth distribution and thus on the mode field distribution, the number of modes and the effective refractive index of each mode, respectively, is investigated. The refractive index depth profile of the integrated-optical polymeric waveguides is examined by using the Mach-Zehnder interferometric method and an image processing technique. The interference phase differences are extracted in order to determine the refractive index depth profiles of the fabricated optical waveguides. After determining the refractive index depth distribution experimentally, the data of the refractive index depth distribution are employed to calculate the mode field distribution, mode numbers and the effective refractive indices.

105-109

Authors: Yaping Yang

This paper reviews the progress of the passive optical network, and discusses a viable means for the realisation of future generation agile gigabits passive optical networks, (GPONs) by the use of low cost narrow band tunable lasers and arrayed waveguide gratings (AWGs). It projectes a two-stage strategy for the realisation of future generation agile GPONs, i.e., the near-term Time and Wavelength Division Multiplexed Gigabits Passive Optical Networks (TWDM-GPONs) and the ultimate Wavelength Division Multiplexed Gigabits Passive Optical Networks (WDM-GPONs). It also presents typical practical designs of narrow band tunable lasers and arrayed waveguide gratings (AWGs) for the agile GPONs.

114-118

Authors: Benkhaouda Soufyane, Sher Zaman, Xin JianGuo

Due to high demand of debris free and high conversion efficiency target for EUV lithography source, We introduce in this article Low-density nanomaterials tin dioxide and tin mono oxide targets for this source. The targets were prepared by refluxing and hydrothermal methods using SnCl2. 2H2O as a precursor. SnO2 spheres like and SnO sheets like images were observed from scanning electron microscopy. The crystal structures of SnO2 and SnO were confirmed by X-Ray diffractions. EUV signal from SnO target at low Nd:YAG energy pulses were more stronger than SnO2.

43-55

Authors: Abhay Kumar Singh

The intensive effort has made to design new amorphous chalcogenide alloy for the photovoltaic as well as other optoelectronics applications. This work describes a short over view on photovoltaic materials, the relevance of inorganic photovoltaic materials, the development history of Cu (InGa) Se (CIGS) photovoltaics, prospects of chalcogenide photovoltaics. Along with the successful synthesis of Cu20(In14Ga9)Se45Te12 (CIGST-1) and Cu25(In16Ga9)Se40Te10 (CIGST-2) chalcopyrite materials in amorphous form. Structural analysis of the bulk materials was performed from the X-ray diffraction (XRD), Field Emission Scanning Microscope (FSEM), Differential Thermal Analyzer (DTA) and micro Raman analysis. While, the presence of elemental concentrations has been confirmed from the Energy Dispersive Spectroscopy (EDS). Subsequently, thermally evaporated thin films surface morphology and roughness parameter have been analyzed by using the Atomic Force Microscopy (AFM). The 100nm thin films, current-voltage (I-V) and resistance-voltage (R-V) characteristics at room temperature and in the temperature range upto 200℃, under applied voltage range upto 40 V have also been discussed. Outcomes of the structural analysis demonstrates bulk materials have an overall amorphous structure, and their thermally evaporated deposited thin films have low roughness. Structural analysis also reveal bulk CIGST-2 composition has single phase amorphous structure. This material thin film has a smooth surface morphology with a lower and higher values of I and R at room temperature. While, in the temperature range up to 200℃ it has a higher and lower I and R respectively. The physical variation in these materials could be explained with the help of the chemical bond theory of solids.

65-69

Authors: Shilpa Jindal, Neena Gupta

The transmission of four active users has been illustrated with 5 WDM × 4 TDM × 4 CODE channel at 20 Gbps data rate 3 Dimensional Optical Code Division Multiple Access system based on newly designed Model A having signature sequences in temporal domain, spectral domain and spatial domain with optical orthogonal codes, cubic congruent operator from algebra theory respectively, using Galois field GF (5) with varying receiver attenuation on optsim simulation software. The results, numerically shown in terms of bit error rate and graphically represented in terms of eye diagram and signal strength, indicate that the novel 3D coding technique is designed to support four users with good BER with variable attenuation at the front end of the receiver.

74-77

Authors: M. Yin, R. Jones

As a factor to limit higher lasing temperature, the rapid lasing intensity degradation in mid-infrared InGaSb/ InAlGaSb quantum well (QW) laser diode has been found and analysed. Due to higher resistance, defects, produced and developed by driving current in p-cladding layer, destroy lattice structure and make the lasing intensity decay. SEM result confirms the defects appeared in p-cladding layer and induced by driving current. Non-radiative recombination induced by defects in the structure is confirmed to result in the optical emission decay at higher temperatures, through the analysis of the electroluminance.

25-32

Authors: Partha Sona Maji, Partha Roy Chaudhuri

The paper reports new results of chromatic dispersion in Photonic Crystal Fibers (PCFs) through appropriate designing of index-guiding triangular-lattice structure devised with a selective infiltration of only the first air-hole ring with index-matching liquid. Our proposed structure can be implemented for both ultra-low and ultra-flattened dispersion over a wide wavelength range. The dependence of dispersion parameter of the PCF on infiltrating liquid indices, hole-to-hole distance and air-hole diameter are investigated in details. The result establishes the design to yield a dispersion of 0±0.15ps/ (nm.km) in the communication wavelength band. The designed proposed pertaining to infiltrating practical liquid for near-zero ultra-flat dispersion of 0±0.48ps/ (nm.km) achievable over a bandwidth of 276-492nm in the wavelength range of 1.26μm to 1.80μm.

1-7

Authors: Masatoshi Tsuji, Wataru Inami, Yoshimasa Kawata

We developed a compact and high-power mode-locked fiber laser for multilayered optical memories. The average power and pulse width of the output pulse from the fiber laser that we developed were 109 mW and 2.1 ps, respectively. The dispersion of the output pulse was compensated with an external single-mode fiber of 2.5 m length. The pulse was compressed from 2.1 ps to 93 fs by dispersion compensation. We proposed a fiber confocal microscope as an alignment-free readout system of multilayered optical memories. The fiber confocal microscope does not require fine pinhole position alignment because the fiber core is used as the point light source and the pinhole, and both of which are always located at the conjugated point. The configuration reduces the required accuracy of pinhole position alignment. The fiber confocal microscope can also achieve a compact pickup head. Recording layers in a multilayered medium could be detected with an axial resolution of approximately 900 nm. We demonstrated eight-layer readout with the fiber confocal microscope.

17-23

Authors: Vipin Kumar, B. Suthar, J. V. Malik, Arun Kumar, Kh. S. Singh, T.P. Singh, A. Bhargva

The properties and origin of defect modes in the one dimensional photonic crystal (PC) with a central defect has been studied. Two types of photonic crystals, each having single defect, namely, symmetric and asymmetric PCs are considered. It is found that a defect mode arise at central wavelength for asymmetric PC, whereas two defect modes arise in the vicinity of central wavelength for symmetric PC. These two defect modes can be fixed to a single central defect by increasing the width of the defect layer. But the intensities of these defect modes are found to be different from the intensities of defect modes for asymmetric case. The origin of these defect modes can be explained using impedance matching condition. The propagation characteristics of the proposed structure are analyzed by using the transfer matrix method.