Ultrathin two-dimensional semiconductors offer exceptional optical responses, making them highly promising for compact photonic structures. In particular, few-layer transition metal dichalcogenides (TMDCs) combine a high refractive index, optical nonlinearity, and anisotropy, enabling the development of miniaturized diffractive optical elements. However, the practical use of TMDCs in photonics is still largely limited by challenges in fabricating micro- and nanostructures with precise, well-defined geometries.
In a new paper published in Light: Advanced Manufacturing , a team of scientists from Center for Photonic Science and Engineering (CPhSE), Skolkovo Institute of Science and Technology, Moscow, Russian Federation have developed a laser-assisted method for fabricating of TMDC-based diffractive elements from chemical precursors directly on functional substrates. Localized laser irradiation triggers chemical reactions within the thiosalt film, inducing spatially selective conversion of the precursor into an amorphous microstructure that can be later post-converted into polycrystalline TMDC during the annealing process. The scalable technique can rapidly produce high-resolution gratings and lenses on a variety of photonic substrates.
“This laser-assisted approach enables the synthesis of MoS2 and WS2 diffractive structures directly from chemical precursors while simultaneously achieving high-precision microstructuring. By using structured light during irradiation, the method allows precise fabrication of diffractive optical elements with extremely high resolution, including gratings and lenses.” the scientists forecast.
The team demonstrated several applications, including grating couplers for chip integration and thin-film focusing elements on ferroelectric substrates, highlighting the method’s potential for future integrated photonic devices.
“Thanks to its precision and scalability, this approach has strong potential to advance photonic platforms based on 2D materials. Moreover, the ability to pattern these structures on functional materials such as ferroelectrics makes them ideally suited for hybrid electro-optic architectures. Such systems can seamlessly integrate passive diffractive elements with active control mechanisms, paving the way for next-generation photonic platforms.” the researchers added.
Light: Advanced Manufacturing
Laser printing of 2D transition metal dichalcogenide diffractive optical elements