The research details two innovative designs: the Ultrathin TiN Grating Metasurface (UTGM), which employs patterned ultrathin TiN films, and the gold resonator/TiN film Hybrid Metasurface (GTHM), integrating C-shaped gold resonators.

A recent study has unveiled a nonlinear optical metasurface technology that holds promise for advancing next-generation communication technologies, including quantum light sources and medical diagnostic devices.

Researchers achieved local phase tuning exceeding 180 degrees and demonstrated THG beam steering through phase gradients, paving the way for adjustable flat nonlinear optical elements.

The findings of this study were published in the journal 'Materials' on October 2, 2024, by a team of researchers led by Panyi Li and including several collaborators.

In the GTHM design, researchers achieved a maximum linear dichroism of 0.95 at 1.8 µm, while the UTGM design demonstrated a maximum transverse magnetic (TM) absorption of 0.96, indicating significant linear dichroism.

The UTGM design specifically showed that TM wave absorption reached 0.96, which is significantly higher than the transverse electric (TE) wave absorption of 0.36 at 1.6 µm.

This cutting-edge metasurface technology enables the creation of compact and lightweight optical instruments, with potential applications for laser devices that could be as thin as paper.

The metasurface is compatible with complementary metal oxide semiconductor (CMOS) technology, facilitating its integration into existing electronic systems.

Molybdenum trioxide (MoO3) was selected as the base material due to its favorable optical properties and absorption capabilities in the infrared spectrum.

The study reported an impressive average absorptivity of 0.950 across the tested range, with a peak absorptivity reaching 0.989.

This research represents a breakthrough in electrical control, allowing for independent modulation of the intensity and phase of third-harmonic generation (THG), which can adjust the wavelength, intensity, and phase of light.