title: Narrow bandpass tunable terahertz filter based on photonic crystal cavity.
abstract: We have fabricated a very narrow bandpass tunable terahertz (THz) filter based on a one-dimensional photonic crystal cavity. Since the filter consists of silicon wafers and air spacers, it has a very high quality factor of about 1500. The full width at half maximum (FWHM) of the passband is only about 200 MHz, and the peak transmission is higher than -4 dB. Besides, the central frequency can be tuned rapidly over the entire bandgap with the length of cavity adjusted by a motorized linear stage. Further analytical calculations indicate that a high-Q tunable filter with both high peak transmission and wide tunable range is possible if thinner silicon layers are used.
authors.affiliation: Centre for THz Research, China Jiliang University, Hangzhou 310018, China. Jlhe@cjlu.edu.cn
authors.forename: Jinglong
authors.initials: J
authors.lastname: He
authors.forename: Pingan
authors.initials: P
authors.lastname: Liu
authors.forename: Yalan
authors.initials: Y
authors.lastname: He
authors.forename: Zhi
authors.initials: Z
authors.lastname: Hong