Refractive index sensing and imaging based on polarization-sensitive graphene.

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Graphene's unique dynamic conductivity offers significant potential for optical applications.
• Polarization-sensitive absorption in graphene spans near-infrared to ultraviolet wavelengths.

Purpose of the Study:

• To theoretically investigate graphene's refractive index sensing and imaging capabilities.
• To explore mechanisms under oblique and tight focusing light incidences.

Main Methods:

• Theoretical investigation of graphene's optical properties.
• Analysis of polarization-sensitive absorption under focused light.

Main Results:

• Achieved ultrahigh refractive index resolution of ~2.09x10^-8 RIU for label-free sensing.
• Demonstrated high transverse spatial resolution (~200 nm) and longitudinal detection length (~750 nm) for imaging.
• Utilized 532 nm incident wavelength for analysis.

Conclusions:

• Graphene-based methods offer superior resolution for refractive index sensing.
• Proposed techniques enable high-resolution imaging with significant depth.
• Potential applications include non-invasive biological sensing and advanced photonic devices.