Millimeter scale electrostatic mirror with sub-wavelength holes for terahertz wave scanning

摘要

This work reports the design, microfabrication, and characterization of highly reflective electrostatic mirrors with sub-wavelength holes for scanning terahertz (THz) waves.The mirror consists of an aluminum coated silicon mirror plate precisely assembled on the top of two axis torsional microactuators.The mirror plate with sub-wavelength microholes not only provides high reflectivity over 98% at THz waves by decoupling the surface plasmon resonance but also reduces air damping by allowing air to flow through the mirror plate during the mirror scanning.The device can provide many opportunities for miniaturized THz time domain spectroscopic imaging systems.