Nanophotonics and Metamaterials

Advanced Optical Applications

My research in nanophotonics and metamaterials focuses on controlling light at the nanoscale by combining graphene with advanced structures like gratings and layered designs. These innovations create exciting opportunities in energy, sensing, and photonics by enabling the tuning of light properties for many applications.

One important achievement in my work is a graphene-covered metallic grating that achieves 98% absorptance in the near-infrared spectrum. This is a big improvement compared to graphene’s natural 2.3% absorptance (see Figure 1). The design combines graphene’s unique properties with resonant modes in the grating, making it useful for ultrafast photodetectors, thermal management, and optical communication while working well across wide incident angles.

I also developed dual broadband infrared absorbers that use magnetic polaritons to achieve very high absorption at two infrared wavelengths (see Figure 2). These absorbers are useful for infrared detection, thermal imaging, and chemical sensing, where sensitivity and working at multiple wavelengths are needed. Another part of my research is optimizing subwavelength aluminum gratings to create strong and tunable absorption peaks with wide spectral widths (see Figure 3). These designs are ideal for energy harvesting, infrared sensing, and thermal management. This shows how computational tools like genetic algorithms can help improve optical designs.

I also worked on double-layered metallic gratings that can fine-tune their optical transmission by adjusting the air gap between the layers (see Figure 4). These designs are very effective for proximity sensors, optical filters, and photonic devices in the visible and near-infrared range. They are also simple and cost-effective, which makes them great for real-world applications.

Figure: (1) Absorptance spectra comparing structures with and without graphene, showing enhanced absorption in graphene-covered designs. (2) Dual-band absorption peaks for a double-layered compound grating (DLCG) with and without graphene overlay, highlighting the impact of graphene on absorptance. (3) Absorptance as a function of wavelength for varying the grating thickness in double-layered structures, illustrating tunability of spectral response. (4) Simulated field distributions showing resonant modes and energy localization in the grating structures.(5) A 3D representation of our photonic structure design.

These studies show how integrating graphene with nanostructures can achieve amazing control over light and its properties. From improving light absorption to precisely tuning the spectrum, my work demonstrates the potential of nanophotonics and metamaterials for solving modern challenges and creating new innovations.

REFERENCES

  1. “Ultra-wide spectral bandwidth and enhanced absorption in a metallic compound grating covered by graphene monolayer”, Nghia Nguyen-Huu*, Jaromir Pištora, Michael Cada, Trung Nguyen-Thoi, Youqiao Ma, Kiyotoshi Yasumoto, BM Azizur Rahman, Qiang Wu, Yuan Ma, Quang Hieu Ngo, Lin Jie, and Hiroshi Maeda, IEEE Journal of Selected Topics in Quantum Electronics, 2020
  2. “Dual broadband infrared absorptance enhanced by magnetic polaritons using graphene-covered compound metal gratings”, Nghia Nguyen-Huu*, Jaromir Pištora, and Michael Cada, Optics Express, 2019
  3. “Control of infrared spectral absorptance with one-dimensional subwavelength gratings”, Nghia Nguyen-Huu, and Yu-Lung Lo*, IEEE/OPTICA Journal of Lightwave Technology, 2013
  4. “Tailoring the optical transmission spectra of double-layered compound metallic gratings”, Nghia Nguyen-Huu, and Yu-Lung Lo*, IEEE Photonics Journal, 2013