| 摘要 |
"BIREFRINGENT SINGLE-MODE ACOUSTIC FIBER" A birefringent single-mode acoustic fiber for propagating linearly polarized shear acoustic waves while preserving linear polarization, comprises an elongated core region of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components, and a cladding region enclosing all surfaces of the core region except end surfaces thereof, the cladding region being also of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components. The core and cladding regions have different shear wave velocities with the shear wave velocity of the core region being lower than that of the cladding region, at least one the regions being characterized by at least one birefringence causing factor for breaking degeneracy between the two orthogonal shear mode components and preserving linear polarization thereof throughout the fiber. The birefringent single-mode acoustic fiber according to the invention is particularly useful in acoustic fiber sensor systems for monitoring environmental changes in pressure, temperature, strain, stress, etc. |
