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Author

S. Revathi

Bio: S. Revathi is an academic researcher from VIT University. The author has contributed to research in topics: Photonic-crystal fiber & Birefringence. The author has an hindex of 4, co-authored 7 publications receiving 51 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a spiral photonic crystal fiber with elliptical air holes was designed to achieve high birefringence, large nonlinearity, and negative dispersion.
Abstract: We propose and design a spiral photonic crystal fiber with elliptical air holes for achieving high birefringence, large nonlinearity, and negative dispersion. The structure is designed using chalcogenide glass (As2S3) for different ellipticity ratios of air holes in the cladding and the effect on various properties is observed. The proposed structure has birefringence of the order 10−2, nonlinearity of 26739.42 W−1 m−1, and dispersion of −1136.69 at 0.85 μm. An accurate numerical approach based on finite element method is used for the design and simulation of the structure. Due to high birefringence and negative dispersion, the proposed structure can be used for polarization control and dispersion compensation, respectively.

29 citations

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TL;DR: In this article, a spiral photonic crystal fiber with circular air holes for achieving high birefringence, large nonlinearity and large negative dispersion was proposed. But the design of the fiber was not discussed.
Abstract: This paper presents a soft glass spiral photonic crystal fiber with circular air holes for achieving high birefringence, large nonlinearity and large negative dispersion. The material used here for designing the fiber is soft glass (SF-57). A central defect air hole is being introduced in the core for achieving high birefringence and for different ellipticity ratios the effect of various optical properties of a photonic crystal fiber are studied. The structure proposed has a high birefringence in the order of 10 –2 , high nonlinearity of 5828 W –1 km –1 and high negative dispersion of –1546.6 ps/nm·km at 0.850 μm. A numerical approach based on the finite element method is used for the design and simulation of the structure. Due to the optimization in the cladding air holes, the fiber can be used as polarization maintaining fibers, in dispersion compensation and other nonlinear applications.

14 citations

Journal ArticleDOI
01 Nov 2015-Optik
TL;DR: In this paper, a new type of microstructured fiber known as dual core photonic quasi-crystal fiber is proposed for pressure and temperature sensor based on the mode coupling of the two fiber cores.

12 citations

Journal ArticleDOI
TL;DR: In this article, the bending radius along with the angle in the direction of the bending and the effects due to these angles are extensively studied by using Finite Element Method (FEM).
Abstract: Objectives: Bending insensitive Photonic Crystal Fiber will possess low loss and the research aims for high birefringence and large nonlinearity. Bending insensitive Photonic Crystal Fiber (PCF) along with high birefringence and high nonlinearity is being presented in this paper. Methodology: The fiber is bent by applying some bending radius along with the angle in the direction of the bending and the effects due to these angles are being extensively studied by using Finite Element Method (FEM). Findings: The birefringence in the range of 10−2 can be achieved and nonlinear coefficient in the range of 70-110 W−1Km−1 can be obtained. The PCF possesses very low effective mode field area (MFA) which would be leading to positive effect on the bending losses. The number of air hole rings used in the designed structure is very less so the designed fiber is easy to fabricate. Applications: This fiber can be used in the medical applications for detecting the tumors, for Optical Code Division Multiple Access (OCDMA) applications, high power laser applications.

4 citations

Journal ArticleDOI
TL;DR: The combustion-based synthesis of BFO and Gd:BiFeO3 perovskite nanoparticles was presented in this paper , where it was found that the BFO nanoparticles exhibited an uneven shape, a tendency to agglomerate, and fused grains with defined grain boundaries.
Abstract: We present the combustion-based synthesis of BiFeO3 (BFO) and Gd:BiFeO3 perovskite nanoparticles. XRD analysis demonstrates that the undoped BFO (x = 0) perovskite sample shows a single perovskite phase with a rhombohedral structure. However, increase in the Gd3+ content from x = 0.05 and 0.15 to 0.25 led to the occurrence of a structural phase transformation from rhombohedral (BiFeO3) to orthorhombic (Bi2Fe4O9). With an increase in the Gd-dopant the average crystallite size of rhombohedral structures increased from 16 to 23 nm. The perovskite samples were examined using XPS, which confirmed the presence of Bi3+, Gd3+, Fe2+, and O2+ ions. FT-IR spectroscopy indicated the existence of elemental functional groups in the synthesized perovskite nanoparticles. Furthermore, the direct band gap measured by DRS reduced from 2.16 to 2.0 eV as the Gd concentration increased. The nanoparticles of the BFO perovskite had an uneven shape, a tendency to agglomerate, and fused grains with defined grain boundaries. At ambient temperature, both the undoped and Gd:BFO perovskite nanoparticles exhibit a ferromagnetic characteristic. It was found that the BET surface area of the undoped and Gd-doped BFO perovskite nanoparticles varied progressively from 4.38 to 33.52 m2 g-1. The catalytic oxidation studies conducted in a batch reactor under air conditions revealed that the synthesized catalysts, in particular, Gd:BFO (x = 0.25), exhibited higher conversion and selectivity efficiencies for glycerol (con. 100% and sel. 99.5%, respectively).

1 citations


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01 Jan 2002
TL;DR: In this article, a review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime.
Abstract: A topical review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime. Results from numerical simulations are used to discuss the temporal and spectral characteristics of the supercontinuum, and to interpret the physics of the underlying spectral broadening processes. Particular attention is given to the case of supercontinuum generation seeded by femtosecond pulses in the anomalous group velocity dispersion regime of photonic crystal fiber, where the processes of soliton fission, stimulated Raman scattering, and dispersive wave generation are reviewed in detail. The corresponding intensity and phase stability properties of the supercontinuum spectra generated under different conditions are also discussed.

360 citations

Journal ArticleDOI
TL;DR: In this paper, a novel D-shaped photonic crystal fiber (D-PCF) is proposed to concurrently achieve ultra-high nonlinearity, birefringence, and numerical aperture profile.

40 citations

Journal ArticleDOI
TL;DR: In this paper, a novel design of circular hybrid photonic crystal fiber (CH-PCF) with high nonlinearity and high numerical aperture (NA) is introduced by using finite element method (FEM) and selecting finer mesh.

38 citations

Journal ArticleDOI
TL;DR: In this article, a novel design of circular hybrid photonic crystal fiber (CH-PCF) with highly nonlinearity and high numerical aperture (NA) was introduced by employing the finite element method (FEM) and selecting finer mesh.
Abstract: A novel design of circular hybrid photonic crystal fiber (CH-PCF) with highly nonlinearity and high numerical aperture (NA) is introduced in this paper. The numerical simulation results are obtained by employing the finite element method (FEM) and selecting finer mesh. The investigated parameters are nonlinearity, effective area, scattering loss, power fraction and NA for the two fundamental polarized modes. Significant improvement of PCFs in terms of the non-linearity and numerical aperture are demonstrated by carefully investigation of the structure geometrical parameter. The reported design has high nonlinearity of 62448.64 W−1 km−1 and 63435.74 W−1 km−1 at the operating wavelength of 1.00 μm along with numerical aperture of 0.783 and 0.784 at the operating wavelength of 2.00 μm for both fundamental x-polarization mode and for y-polarization mode, respectively. So, the obtained extraordinary outcomes make the proposed PCF a strong candidate in super continuum generation and biomedical imaging applications.

34 citations

Journal ArticleDOI
TL;DR: In this paper, a unique design of Photonic Crystal Fiber (PCF) is discussed to introduce one of the highest numbers of OAM modes for the very first time with a very large bandwidth of 1,900nm.

33 citations