Narrow bandpass tunable terahertz filter based on photonic crystal cavity

Jinglong He; Pingan Liu; Yalan He; Zhi Hong

doi:10.1364/AO.51.000776

Narrow bandpass tunable terahertz filter based on photonic crystal cavity

Appl Opt. 2012 Feb 20;51(6):776-9. doi: 10.1364/AO.51.000776.

Authors

Jinglong He¹, Pingan Liu, Yalan He, Zhi Hong

Affiliation

¹ Centre for THz Research, China Jiliang University, Hangzhou 310018, China. Jlhe@cjlu.edu.cn

PMID: 22358169
DOI: 10.1364/AO.51.000776

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.