Recently, Dr. Muhammad Shemyal Nisar, one of SBC engineering lecturers, published an article titled On-chip beam steering through reprogrammable integrated coding metasurfaces in Results in Physics as the first author (4.565, JCR-Q2).
Metasurfaces are artificially created subwavelength structures that are used to achieve a certain functionality for a photonic device. The advantage of metasurfacs for these applications is the improved control over the phase and amplitude of the transmitted and reflected waves that the metasurfaces facilitate.
Coding metasurfaces, which quantizes the phase response of the unit cell of the metasurface, have found many applications in free space optics, but have not been used for integrated photonic applications. This can partly be attributed to the lack of implements to usefully implement such a framework in practice. The advent of low-loss phase change materials such as Sb2S3 has changed this by enabling the implementation of reprogrammable integrated metasurfaces.
This manuscript presents the first ever integrated implementation of coding metasurface - Sb2S3 based 1-bit and 2-bit coding metasurfaces that can potentially also be practically implemented. These metasurfaces can achieve functionalities such as beam focusing, beam splitting, and beam steering through the rearrangement of the material phase of Sb2S3. This can be useful for several applications in integrated photonics including but not limited to a photonic computational platform.