Refractive index sensor with alternative high performance using black phosphorus in the all-dielectric configuration

Area of Science:

• Photonics and Nanomaterials
• Optical Sensing Technologies
• Infrared Spectroscopy

Background:

• Traditional optical sensors often face limitations in sensitivity and cost-effectiveness.
• Black phosphorus (BP) exhibits unique anisotropic properties suitable for advanced optical applications.
• All-dielectric nanostructures offer promising platforms for high-performance sensing.

Purpose of the Study:

• To theoretically propose and analyze a nonplasmonic optical refractive index sensor.
• To investigate the role of black phosphorus's anisotropic properties in sensor performance.
• To explore the potential for high sensitivity and figure of merit (FOM) in infrared sensing.

Main Methods:

• Theoretical proposal of a sensor utilizing a black phosphorus monolayer and dielectric materials.
• Analysis of sensor performance across different crystal directions of BP.
• Verification of simulation results using coupled-mode theory (CMT).
• Investigation of the impact of sample properties and incident angle on sensor performance.

Main Results:

• The proposed sensor demonstrates tunable sensitivity and FOM due to BP's anisotropy.
• High sensitivity and FOM are achieved through strong magnetic resonance in the all-dielectric configuration.
• The sensor's performance is influenced by sample characteristics and incident angle.

Conclusions:

• A cost-effective, high-performance optical refractive index sensor based on a BP monolayer is proposed.
• The design offers significant potential for advanced infrared sensing applications.
• The all-dielectric approach with anisotropic materials provides a promising route for future sensor development.