Nonlinear Mid-Infrared Metasurface based on a Phase-Change Material

The mid-wave infrared (MWIR) spectral region (3-5 mu m) is important to a vast variety of applications in imaging, sensing, spectroscopy, surgery, and optical communications. Efficient third-harmonic generation (THG), converting light from the MWIR range into the near-infrared, a region with mature optical detection and manipulation technologies, offers the opportunity to mitigate a commonly recognized limitation of current MWIR systems. In this work, the possibility of boosting THG in the MWIR through a metasurface design is presented. Specifically, a 30-fold enhancement in a highly nonlinear phase-change material Ge2Sb2Se4Te1 (GSST) is demonstrated by patterning arrays of subwavelength cylinders supporting a magnetic dipolar resonance. The unprecedented broadband transparency, large refractive index, and remarkably high nonlinear response, together with unique phase-change properties, make GSST-based metasurfaces an appealing solution for reconfigurable and ultra-compact nonlinear devices operating in the MWIR.

Automated summary

This research demonstrates the possibility of enhancing third-harmonic generation (THG) in the mid-wave infrared (MWIR) range through designing a metasurface, with a 30-fold enhancement achieved using a highly nonlinear material Ge2Sb2Se4Te1 (GSST). GSST-based metasurfaces offer unprecedented broadband transparency, large refractive index, high nonlinear response, and unique phase-change properties, making them an attractive solution for reconfigurable and ultra-compact nonlinear devices operating in the MWIR.