摘要
We numerically investigate the trade-offs between the dispersion properties,coupling efficiency,and geometrical constraints in dual-wire （twin-lead） terahertz （THz） waveguides.In particular,we show that their inherent linearly polarized quasi-transverse electromagnetic （TEM） modes exist for waveguide transverse dimensions comparable with the wavelength,enabling significant end-fire coupling （10%） for numericalaperture limited Gaussian beams while supporting a relatively low-dispersion propagation of below 0.5 ps 2 /m,as desired for short-pulse time-domain spectroscopy applications.Starting from the dual-wire structure,we also demonstrate that low-dispersion tapers can be designed to improve coupling efficiency.
We numerically investigate the trade-offs between the dispersion properties,coupling efficiency,and geometrical constraints in dual-wire （twin-lead） terahertz （THz） waveguides.In particular,we show that their inherent linearly polarized quasi-transverse electromagnetic （TEM） modes exist for waveguide transverse dimensions comparable with the wavelength,enabling significant end-fire coupling （10%） for numericalaperture limited Gaussian beams while supporting a relatively low-dispersion propagation of below 0.5 ps 2 /m,as desired for short-pulse time-domain spectroscopy applications.Starting from the dual-wire structure,we also demonstrate that low-dispersion tapers can be designed to improve coupling efficiency.
基金
supported by the FQRNT (Le Fonds Qubcois de la Recherche sur la Nature et les Technologies)
the Natural Sciences and Engineering Research Council of Canada (NSERC)
the NSERC Strategic Projects
the INRS. M. P. wishes to acknowledge a Marie Curie Outgoing International Fellowship (No. PIOF-GA-2008-221262)
