Photonics and Optoelectronics
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Open Access journal
ISSN (Print) 2304-1064 - ISSN (Online) 2304-1072
Published by Science and Engineering Publishing Company [49 journals]
- The Relationship between the Structure and the Binding to Bovine Serum
Albumin of Some Styrylcyanine Dyes
Abstract: The Relationship between the Structure and the Binding to Bovine Serum Albumin of Some Styrylcyanine Dyes
Author Gairat KhodjayevEldar N. KurtalievNegmat Nizomo
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.
- Optical Studies on L-Tartaric acid and L-Prolinium Tartrate
Abstract: Optical Studies on L-Tartaric acid and L-Prolinium Tartrate
Author K. MoovendaranS. NatarajanV. Jayaramakrishna
Bulk-size single crystals of the nonlinear optical (NLO) materials: L-tartaric acid (LTA) and L-prolinium tartrate (LPT) were grown from aqueous solution using a home made crystal growth setup. Characterization of the crystals was investigated using single crystal X-ray diffraction. UV-vis-NIR spectra showed that the crystals have excellent transparency in the visible and infrared regions. Tentative assignments were made for the IR absorption peaks. The birefringence of the crystals was measured in the visible region and it was found to be varying with wavelength. Photoluminescence excitation studies showed that the emission occurred at 397 and 375 nm respectively, for LTA and LPT. The second harmonic generation (SHG) conversion efficiency of the powder samples of the crystals were measured as about 40% and 95% respectively, compared to that of the standard KDP crystals.
- Shear Bond Strength of Different Adhesive Systems on Enamel Prepared by
Er: YAG LASER
Abstract: Shear Bond Strength of Different Adhesive Systems on Enamel Prepared by Er: YAG LASER
Author João C. FerreiraSofia Arantes-OliveiraWalter R. DiasPaulo R. MeloPatrícia T. PiresÁlvaro F. Azeved
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
- Effect of Laser Thermal Shock Test Parameters on the Temperature Field of
Abstract: Effect of Laser Thermal Shock Test Parameters on the Temperature Field of Piston
Author Pang MingYuan XiaoyanXie ZhiminHu DingyunQiang Hu
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.
- Design of Light Trapping Structures for Ultrathin Solar Cells
Abstract: Design of Light Trapping Structures for Ultrathin Solar Cells
Author Xiaowei GuoJia LiuShouqiang Zhan
The conversion efficiency of thin film silicon solar cell is still much below that of wafer silicon solar cell due to low optical absorption. Light trapping techniques can enhance the optical absorption in solar cells. Here, we design light trapping structures of double-side grating for ultrathin silicon solar cells based on a rigorous coupled-wave analysis method. The role of each grating was identified by analyzing the absorption spectra of ultrathin solar cell from 350 nm to 1100 nm wavelength at normal incidence, which shows use of top and bottom light trapping structures can achieve large optical absorption in different wave regimes. Inspired by this observation, the dual dielectric/dielectric and dielectric/ metallic grating structures were proposed and optimized to obtain broadband optical absorption close to the theoretic limit.
- Analysis of Dispersion and Attenuation Characteristics of the Bragg Fiber
Abstract: Analysis of Dispersion and Attenuation Characteristics of the Bragg Fiber
Author Zhejno I. ZhejnovJordan R. Urumo
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.
- All-Optical Implementation of Arithmetic Operation Scheme using Optical
Nonlinear Material Based Switching Technique
Abstract: All-Optical Implementation of Arithmetic Operation Scheme using Optical Nonlinear Material Based Switching Technique
Author Samir SahuShantanu Dha
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.
- Near Zero Ultra-flat Dispersion PCF: Properties and Generation of
Abstract: Near Zero Ultra-flat Dispersion PCF: Properties and Generation of Broadband Supercontinuum
Author Partha Sona MajiPartha Roy Chaudhur
We present a new design study of ultra-flat near zero dispersion PCF with selectively liquid infiltration with all uniform air-holes in the cladding towards achieving broadband supercontinuum generation (SCG). With rigorous series study of the optimization process we could achieve near zero ultra-flat dispersion as small as 0±0.41 ps/nm/km for broad wavelength range. The optimized near zero ultra-flat dispersion PCF has been targeted for smooth and flat broadband spectrum supercontinuum generation (SCG) for near Infrared (IR) applications. Broadband SC generations corresponding to three different designs of ultra-flat dispersion fiber have been carried out by using picoseconds pulse laser around the first zero dispersion wavelengths (ZDW). The numerical results show that FWHM of around 400 nm with less than a meter long fiber can be achieved with these fibers that cover most of the communication wavelength bands. The proposed design study will be applicable for applications in the field of tomography, Dense Wavelength Division Multiplexing (DWDM) system and spectroscopy applications etc.
- Tunable Selective Liquid Infiltration: Applications to Low Loss
Birefringent Photonic Crystal Fibers (PCF) and Its Single Mode Realization
Abstract: Tunable Selective Liquid Infiltration: Applications to Low Loss Birefringent Photonic Crystal Fibers (PCF) and Its Single Mode Realization
Author Partha Sona MajiPartha Roy Chaudhur
In this article, we’ve theoretically investigated the application of selective liquid infiltration towards realizing birefringent Photonic Crystal Fiber (PCF) and its operation in the single mode region. Birefringence has been created in a symmetrical structure PCF by infiltrating liquid of certain refractive indices in diagonally opposite air-holes. Different air-hole fraction along with different infiltrating refractive indices has been considered towards studying the effect of the parameters towards birefringence and loss. Cut-off properties for different infiltrating liquid has been performed and it has been found that PCF infiltrated with higher Refractive Indices (RI) liquid is suitable for broader range of single mode operation. The present structure provides very low loss and that can also be minimized with higher number of air-hole rings without affecting the birefringent property. Tunability property of the infiltrating liquid for various temperatures has been studied. By varying the refractive indices of the infiltrating liquid the birefringence can be well tuned. Our research will be useful in designing a birefringent PCF from conventional symmetrical PCF by infiltrating liquids in two diagonally opposite air-holes and proper choice of PCF parameter for single mode operation at a desired wavelength of interest.