| Summary: | 碩士 === 國立中央大學 === 光電科學研究所 === 95 === In this work, we propose a novel output design of the photonic-crystal waveguides (PCWG) structures to investigate the enhancement of the collimated beam that was radiated from PCWG. First, we design novel two-dimensional PCWGs in hexagonal lattice. We simulate and analyze different structures by using the finite-difference time-domain numerical method and the plane wave expansion method. Based on the finite-difference time-domain numerical method, we propose a novel method to calculate the propagation loss and reflection for PCWGs. This method can be applied on single or multimode low-loss PCWGs. On the concept of the Bessel beam, we analyze and discuss the three-dimensional radial PCWG to enhance the collimated beam and propagation distance. The collimated emission is attractive for enhancing the coupling efficiency of light from PCWG into conventional dielectric waveguides, to control the emission direction of PC edge-emitting lasers, to apply to the high power laser to replace the dielectric lenses and to obtain the high collimated microwave beam.
|
|---|
