Laser-induced graphene-enabled thermo-optic switching in a VO ₂ -integrated plasmonic structure

Active control of light–matter interaction is a key requirement for reconfigurable photonic devices. In this work, we demonstrate thermo-optic switching in VO 2 -integrated plasmonic structures enabled by a laser-induced graphene (LIG)-assisted heating mechanism. The 1-D plasmonic array is fabricated using laser-interference lithography, followed by the deposition of gold and VO 2 thin films to support surface plasmon polariton resonance at 1295 nm. Voltage-controlled Joule heating from LIG drives the insulator–metal transition of VO 2 . The device exhibits reversible optical switching with a 30 nm blueshift during the phase transition and a switching contrast of 1.12. The compact and scalable LIG platform enables electrically addressable, low-cost photonic switching suitable for on-chip integration.