Over the past year, I pursued three parallel research projects, achieving promising preliminary outcomes.

1. Generation of Nanoscale Light Field Using Non-Metallic Nanoprobe

Traditionally, nanoscale light field generation depended on metallic materials, which often caused excessive heating. We overcame the challenge of generating a nanoscale light field with a non-metallic probe by employing the longitudinally polarized electric field mode. This method leverages the discontinuity of the electric displacement vector at the probe tip, enabling the formation of a wavelength-insensitive nanoscale light field. The probe tip dimensions dictate the light field's size and offer intensity comparable to metallic probes without the associated heating issues. These findings were shared at the FiOLS 2024 conference, and a detailed journal paper is under preparation.

2. Achieving High Near-Infrared Absorption with an Ultra-Thin Si Grating Layer of Limited Area

To address silicon's poor absorption of near-infrared light, we designed a grating structure based on Guided-Mode Resonance (GMR), which enhances absorption by channeling incident light into transverse resonance modes. The grating layer, only a few hundred nanometers thick, ensures high absorption efficiency and ultrafast response times. This innovative design shows potential applications in ultra-high-speed near-infrared photodetectors. Our findings have been published in Optics Letters.

3. Applying Machine Learning to the Inverse Design of Optical Absorbers

By combining Variational Autoencoders (VAE) and Bayesian Optimization, we demonstrated an efficient inverse design method for optical absorbers. This approach generates absorber structures tailored to specific target spectra and yields diverse, highly efficient results. The methodology, which holds promise for advancing metasurface designs with high degrees of freedom, was presented at ISIPS 2024.