Mechanically tunable metamaterials terahertz dual-band bandstop filter

摘要

We experimentally demonstrate a mechanically tunable metamaterials terahertz (THz) dual-band bandstop filter.The unit cell of the filter contains an inner aluminum circle and an outside aluminum Ohm-ring on high resistance silicon substrate.The performance of the filter is simulated by finite-integration-time-domain (FITD) method.The sample is fabricated using a surface micromachining process and experimentally demonstrated using a THz time-domain-spectroscopy (TDS) system.The results show that,when the incident THz wave is polarized in y-axis,the filter has two intensive absorption peaks locating at 0.71 THz and 1.13 THz,respectively.The position of the high-frequency absorption peak and the amplitude of the low-frequency absorption peak can be simultaneously tuned by rotating the sample along its normal axis.The tunability of the high-frequency absorption peak is due to the shift of resonance frequency of two electrical dipoles,and that of the low-frequency absorption peak results from the effect of rotationally induced transparent.This tunable filter is very useful for switch,manipulation,and frequency selective detection of THz beam.