Electrically driven plasmon chip: Active plasmon filter

We have developed an electrically driven plasmon chip, i.e., an active plasmon filter, consisting of a metallic subwavelength grating modulated by a nano-electro-mechanical system (NEMS) type actuator. The device shifts the plasmon resonance wavelength and the transmittance when an electrical signal is applied. The fabricated filter shows resonance wavelength shifts of 60 nm with a bias voltage of less than 10 V. A rigorous numerical calculation confirms the origin of the surface plasmon resonance and qualitatively explains the effect. Such NEMS optical devices offer rapid voltage-controlled plasmonic tuning of 20 MHz, opening up applications in agile sensing and nanoscale object trapping using actively tailored optical hot spots. (C) 2014 The Japan Society of Applied Physics