Spectral property of leaky waves from planar dielectric waveguide

摘要

We studied the spectral properties of leaky waves radiated from a planar dielectric waveguide. A simple model utilizing ellipse equations is introduced to describe the light interference inside the waveguide, and obtain resonance conditions of leaky waves. We show that our ellipse model predicts the quality factor of resonance as well and they all agree nicely with rigorous numerical results using the finite-difference time domain calculation. In particular, we find the condition for the higher quality factor of the dielectric waveguide system and show that the condition is highly dependent on the cladding material of the system. We also show that the resonance of leaky waves can be explained by linking it to the resonance of a pipe with single open end.