1999/08/27 by D. K. Gramotnev, Dmitri K. Gramotnev, T. A. Nieminen +1 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Acoustic Wave Resonator Technologies #Advanced Fiber Optic Sensors #Optical Coatings and Gratings #physics.optics
paper · pdf · doi:10.1088/1464-4258/1/5/310
published as Journal of Optics A: Pure and Applied Optics 1, 635-645 (1999) · 13 pages, 10 figures
openalex publication_date 1999/08/27 · arxiv created 2003/11/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
This paper analyses theoretically and numerically the effect of varying grating amplitude on the extremely asymmetrical scattering (EAS) of bulk and guided optical modes in non-uniform strip-like periodic Bragg arrays with stepwise and gradual variations in the grating amplitude across the array. A recently developed new approach based on allowance for the diffractional divergence of the scattered wave is used for this analysis. It is demonstrated that gradual variations in magnitude of the grating amplitude may change the pattern of EAS noticeably but not radically. On the other hand, phase variations in the grating may result in a radically new type of Bragg scattering - double-resonant EAS (DEAS). In this case, a combination of two strong simultaneous resonances (one with respect to frequency, and another with respect to the phase variation) is predicted to take place in non-uniform arrays with a step-like phase and gradual magnitude variations of the grating amplitude. The tolerances of EAS and DEAS to small gradual variations in the grating amplitude are determined. The main features of these types of scattering in non-uniform arrays are explained by the diffractional divergence of the scattered wave inside and outside the array.