High-Sensitivity Room-Temperature Power Sensor Based on a Graphene Oxide-PDMS Bilayer and Surface Plasmon Resonance
Giancarlo Margheri1, Tommaso Del Rosso2
1Institute for Complex Systems, National Council of Researches of Italy, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
Abstract:
The accurate detection and quantification of electromagnetic radiation in the infrared (IR) and terahertz (THz) regions are critical for modern applications, yet they remain challenging due to the "THz gap" and the limitations of current room-temperature technologies. This paper proposes a novel uncooled IR-THz power sensor based on a hybrid graphene oxide (GO) and polydimethylsiloxane (PDMS) bilayer integrated into a surface plasmon resonance (SPR) architecture in the Kretschmann configuration. The device exploits the broadband optical absorption of GO to efficiently convert incident radiation into heat, while the high thermo-optic coefficient of the PDMS layer translates these thermal variations into measurable refractive index shifts. Finite Element Method (FEM) modeling was employed to optimize the sensor design, predicting a linear angular shift of 0.093 deg/mW. Experimental results confirm the theoretical expectations, demonstrating a high sensitivity of 0.083 deg/mW and an exceptionally low limit of detection and resolution on the order of 15 nW. By eliminating the need for cryogenic cooling or vacuum packaging, this platform offers a compact, low-cost, and high-performance solution for next-generation IR-THz metrology.
