MORPHOLOGY-DEPENDENT RESONANCES IN AN OPTICAL-FIBER - EFFECTS OF FIBER TILT AND FOCUSED GAUSSIAN-BEAM ILLUMINATION

Spiral morphology-dependent resonances have been observed in a tilted optical fiber. The polarization-preserving and the cross-polarized ela stic-scattering spectra for plane-wave illumination show that the wave lengths of the resonances are blueshifted quadratically as the fiber t ilt angle increases. When a focused Gaussian beam illuminates the fibe r at its edge, the resonances are blueshifted and broadened as the det ector is offset from the scattering plane with the maximum scattering intensity. The blueshift with focused beam illumination is also a cons equence of the spiral resonances. (C) 1998 Optical Society of America.