A multichannel color filter with the functions of optical sensor and switch

Area of Science:

• Nanophotonics
• Plasmonics
• Optical Engineering

Background:

• Optical filters are crucial for wavelength selection in various applications.
• Metal-insulator-metal (MIM) structures offer unique plasmonic properties for light manipulation.
• Developing integrated optical sensors and switches is a key goal in photonics.

Purpose of the Study:

• To design and analyze a multichannel color filter with integrated optical sensing and switching capabilities.
• To explore the use of surface plasmon polaritons (SPPs) for precise light filtering.
• To achieve high performance metrics for sensing and optical switching functions.

Main Methods:

• Utilized a metal-insulator-metal (MIM) bus waveguide coupled to six circular cavities of varying sizes.
• Employed the finite element method (FEM) to analyze electromagnetic field distributions and transmittance.
• Investigated light-matter resonance and interference of SPP modes for color filtering.

Main Results:

• The designed structure filters ultra-violet and visible light (350-700 nm) into eleven individual color channels.
• Achieved a narrow full width at half maximum (FWHM) of approximately 2 nm for each channel.
• Demonstrated high performance with maximum sensitivity of 700 nm/RIU, figure of merit of 350 1/RIU, and extinction ratio of 174.50 dB.

Conclusions:

• The proposed plasmonic filter effectively separates colors by exploiting SPP modes and interference.
• The device exhibits excellent sensor performance and optical switching capabilities.
• This nanophotonic device offers a promising platform for advanced optical applications.