Title :
Analysis of weakly guiding cladded acoustic fibers of hexagonal crystal symmetry
Author :
Dai, J.D. ; Winkel, V. ; Oliveira, J.E.B. ; Jen, C.K.
Author_Institution :
Dept. of Electr. Eng., McGill Univ.. Montreal, Que., Canada
Abstract :
An approximate analysis of the weakly guiding cladded acoustic fiber consisting of a core and infinite thick cladding both with hexagonal crystal symmetry is presented. The crystalline Z axis is parallel to the fiber axis. Weak guidance conditions require that the stiffness constants of the core are slightly less than those of the cladding, and the density of the core and cladding are almost the same. Approximate dispersion and cutoff equations are derived for all pure guided modes. Dispersion curves of several lower-order guided torsional, radial-axial and flexural modes are evaluated using both exact and approximate formulas and they are in good agreement. A simple approximate dispersion equation for leaky (longitudinal-type) modes is also obtained.<>
Keywords :
acoustic dispersion; acoustic wave propagation; acoustic waveguides; fibres; acoustic fiber theory; approximate formulas; crystalline Z axis; cutoff equations; dispersion curves; dispersion equation; exact formulas; fiber axis; flexural modes; guided flexural modes; guided radical-axial modes; guided torsional modes; hexagonal crystal symmetry; infinite thick cladding; leaky modes; longitudinal modes; lower order modes; pure guided modes; stiffness constants; weak guidance conditions; weakly guiding cladded acoustic fibers; Acoustic propagation; Acoustic waves; Brazil Council; Crystallization; Dispersion; Equations; Finite element methods; Maintenance engineering; Optical fiber polarization; Optical fiber theory;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
