Journal of Power System Engineering (동력기계공학회지)

The Korean Society for Power System Engineering (한국동력기계공학회)
권호 표지
DOI QR코드

DOI QR Code

Structural Analysis of a Cavitary Region Created by Femtosecond Laser Process

  • Fujii, Takaaki (Department of Information System Science, Soka University) ;
  • Goya, Kenji (Department of Information System Science, Soka University) ;
  • Watanabe, Kazuhiro (Department of Information System Science, Soka University)
  • Received : 2014.12.29
  • Accepted : 2015.04.10
  • Published : 2015.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Femtosecond laser machining has been applied for creating a sensor function in silica glass optical fibers. Femtosecond laser pulses make it possible to fabricate micro structures in processed regions of a very thin glass fiber line because femtosecond laser pulses can extremely minimize thermal effects. With the laser machining to optical fiber using a single shot of 210-fs laser at a wavelength of 800 nm, it was observed that a processed region surrounded a thin layer which seemed to be a hollow cavity monitored by scanning electron microscopy (SEM). This study aims at a theoretical investigation for the processed region by using a numerical analysis in order to embed sensing function to optical fibers. Numerical methods based finite element method (FEM) has been used for an optical waveguide modeling. This report suggests two types modeling and describes a comparative study on optical losses obtained by the experiment and the numerical analysis.

Keywords

References

  1. A. Maruta, 1994, "Transparent Boundary for Finite-Element Beam-Propagation Method", The Institute of Electronics, Information and Communication Engineers, Vol.J77-C-1, No. 2, pp. 35-40.
  2. T. Hosono and K. Tanaka, 2009, "Progress and Perspective in Electromagnetic Theory - Some Problems in Electromagnetic Theory and Numerical Techniques in Computational Electromagnetics", The Institute of Electronics, Information and Communication Engineers, Vol.J92-C (8), pp. 314-324.
  3. T. Fujisawa and M. Koshiba, 2002, "Full-Vector Finite-Element Beam Propagation Method for Three-Dimensional Nonlinear Optical Waveguides", The Institute of Electronics, Information and Communication Engineers, Vol.J85-C, No. 6, pp. 440-448.
  4. K. Nagaya and K. Poltorak, 1988, "Method for Solving Eigenvalue Problems of Helmholtz's Equation Having a Circular Outer and a Number of Eccentric Circular Inner Boundaries", Transactions of the Japan Society of Mechanical Engineers, Vol. 54, pp. 2815-2821. https://doi.org/10.1299/kikaic.54.2815
  5. M. Takata, 2002, "A Study on Conductor Surface Impedance Boundary Condition on FDTD Method", IEICE, 13.
  6. A. Maruta, 1994, "Transparent Boundary for Fnite-Elemtnt Beam-Propagation Method", IEICE, Vol. 77, pp. 35-40.
  7. S. Kawabata, 1997, "Determination of the Film Thickness and the Effective Medium Approximation Theories in Ellipsometry", Journal of the Surface science society of Japan, Vol. 18, No. 11, pp. 681-686. https://doi.org/10.1380/jsssj.18.681