Asymmetric scattering and nonorthogonal mode patterns in optical microspirals

2008/10/09 by Jan Wiersig, Sang Wook Kim, Martina Hentschel · 3 citations
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Mechanical and Optical Resonators #Photonic and Optical Devices #cond-mat.other #nlin.CD #physics.optics

paper · pdf · doi:10.1103/physreva.78.053809

8 pages, 10 figures

arxiv created 2008/10/09 · openalex publication_date 2008/11/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Quasibound states in an open system do not in general form an orthogonal and complete basis. It is, however, expected that the nonorthogonality is weak in the case of well-confined states, except close to a so-called exceptional point in parameter space. We present numerical evidence showing that for passive optical microspiral cavities the parameter regime where the nonorthogonality is significant is rather broad. Here we observe almost-degenerate pairs of well-confined modes which are highly nonorthogonal. Using a non-Hermitian model Hamiltonian we demonstrate that this interesting phenomenon is related to the asymmetric scattering between clockwise and counterclockwise propagating waves in the spiral geometry. Numerical simulations of ray dynamics reveal a clear ray-wave correspondence.

Citations

• Model for chaotic dielectric microresonators
• Repulsion of Resonance States and Exceptional Points
• Large Petermann factor in chaotic cavities with many scattering channels
• Exceptional Points of Non-hermitian Operators
• Quantum limit of the laser line width in chaotic cavities and statistics of residues of scattering matrix poles
• Classical Electrodynamics

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