Integrated Nanophotonic Polarizer-Filters for Compact Optical Systems

Polarizers and color filters

My research focuses on advancing the design and development of optical filters and polarizers for high-performance displays and sensing technologies. By utilizing subwavelength metallic gratings (SWMGs) and resonant waveguide-metallic gratings (RWMGs), I have created integrated devices capable of performing color filtering and polarization simultaneously. These innovative approaches significantly enhance the efficiency and functionality of modern screens and photonic systems.

The figures below show highlights from the research, including transmission efficiencies and advanced filtering designs. For a detailed understanding of the methodologies and results, please refer to the original publications: Ref. [1-3]

In my paper, “Realization of integrated polarizer and color filters based on subwavelength metallic gratings using a hybrid numerical scheme,” we demonstrated high transmission efficiency with multi-layer SWMG designs. Key findings include:

  • A single-layer grating that effectively combined polarization and color filtering for LCD applications, achieving up to 50% transmission efficiency at RGB wavelengths (see Figure 1).
  • A double-layer grating that improved filtering performance, reaching approximately 60 dB for polarizing effects, making it ideal for compact, integrated devices (see Figure 2).
    • Transmission of a single-layer grating in Figure 1 and of a double-layer grating in Figure 2 (RGB filters)

    Another publication, “Color filters featuring high transmission efficiency and broad bandwidth based on resonant waveguide-metallic grating,” explored RWMG structures to achieve broader spectral bandwidths and higher efficiency for advanced displays and imaging systems. Highlights include:

  • A double-layer RWMG with silver gratings, optimized to achieve transmission efficiencies of up to 82% for red and 66% for blue, with a wide bandwidth of 125 nm, making it suitable for high-definition displays (see Figure 3).
  • A triple-layer RWMG, which further enhanced transmission efficiency and bandwidth, enabling precise color control (illustrated in Figure 4).
    • Transmission of a double-layer RWMG (Red filter) in Figure 3 and of a triple-layer RWMG (Red filter) in Figure 4

    These findings demonstrate the potential of nanophotonic structures to revolutionize consumer electronics and optical communication systems, setting a new benchmark in color filtering and polarization technologies.

    REFERENCES

    1. “Realization of integrated polarizer and color filters based on subwavelength metallic gratings using a hybrid numerical scheme”, Nghia Nguyen-Huu, Yu-Lung Lo*, Yu-Bin Chen, and Tsai-Yu Yang, Applied Optics, 2011
    2. “Color filters featuring high transmission efficiency and broad bandwidth based on resonant waveguide-metallic grating”, Nghia Nguyen-Huu, Yu-Lung Lo*, and Yu-Bin Chen, Optics Communications, 2011
    3. “Subwavelength metallic gratings as an integrated device - polarized color filter”, Nghia Nguyen-Huu, Yu-Lung Lo*, Yu-Bin Chen, and Tsai-Yu Yang, Conference paper, Photonics West, Optical Components and Materials VIII, 2011