Electrically controlled infrared optical transmission and reflection through metallic grating using NEMS technology

Abstract

The enhanced optical properties of metallic subwavelength gratings with very narrow slits have recently been extensively studied in the field of plasmonics. The optical transmission and reflection of such nanostructures, which act as nano-electro-mechanical systems (NEMS) actuators, can be electrically controlled by varying their geometrical parameters, giving them great flexibility for numerous applications in photonics, opto-electronics, and sensing. The previous challenges in controlling the optical properties were overcome by forming a metallic subwavelength grating with an NEMS actuator in mid-air, allowing the grating to be physically moved with the bias voltage. The device can shift the plasmon resonance wavelength with an electrical signal. The resonance wavelength for Wood’s anomaly at the infrared region is predicted through simulations to shift by approximately 150 nm. We discuss the effect of polarization on the optical properties and grating mechanism. The reported effect may be used to achieve active spectral tuning and switching in a wide range of applications.