Open AccessHighly-efficient directional emission from photonic crystal waveguides for coupling of freely propagated terahertz waves into Si slab waveguides
Author(s) -
Yuanliang Zhang,
Yao Zhang,
Baojun Li
Publication year - 2007
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.009281
Subject(s) - terahertz radiation , optics , photonic crystal , waveguide , coupling (piping) , photonic integrated circuit , transverse plane , slab , power dividers and directional couplers , physics , interference (communication) , optoelectronics , materials science , telecommunications , channel (broadcasting) , structural engineering , computer science , metallurgy , engineering , geophysics
We discuss, by a finite-difference time-domain method, a photonic crystal structure with two adjacent parallel line-defect waveguides to provoke highly-efficient directional emission of terahertz waves. The output field is analogous to a two-point-source interference pattern. Numerical simulations show that the maximum directional emission efficiency is up to 75%. Moreover, the efficiency is insensitive to transverse alignment error and angular alignment error. This structure is potentially important for high-efficiency coupling between freely propagated terahertz waves and Si waveguide systems.