Electrooptic modulation in thin film barium titanate plasmonic interferometers

Area of Science:

• Photonics and Plasmonics
• Materials Science
• Optoelectronics

Background:

• Surface plasmon polaritons (SPPs) enable light manipulation at the nanoscale.
• Active plasmonic devices require dynamic control over SPP properties.
• Metal-dielectric structures are key components in plasmonic interferometers.

Purpose of the Study:

• To demonstrate voltage-controlled modulation of the surface plasmon polariton wavevector.
• To investigate the use of electrooptic barium titanate in active plasmonic interferometers.
• To analyze the mechanisms behind light modulation in the fabricated devices.

Main Methods:

• Fabrication of subwavelength plasmonic interferometers using silver and barium titanate thin films.
• Milling pairs of parallel slits in silver layers.
• Applying external voltage across the barium titanate dielectric layer to modulate plasmon-mediated transmission.

Main Results:

• Successful control of the SPP wavevector in an active metal-dielectric plasmonic interferometer.
• Voltage-induced modulation of plasmon-mediated light transmission through subwavelength slits.
• Observed modulation attributed to electrooptic effects and domain switching in barium titanate.

Conclusions:

• Electrooptic barium titanate can be effectively used as a dielectric layer for active plasmonic interferometers.
• External voltage provides a viable method for modulating light transmission in such devices.
• The findings open possibilities for tunable nanoscale optical components and devices.