Assessment of Laser-Damage Performance of Meta-Surface Material to Enable High-Speed Laser Beam Control

Eyal Feigenbaym | 19-FS-032

Project Overview

We studied the laser-induced damage limitations of a no-moving-part, ultrafast laser beam steering and arbitrary reshaping technology based on electro-optically modulated metasurfaces at one-meter wavelength for pulsed and continuous wave laser operation, which is an under-studied aspect of these devices that is critical to their potential operation and deployment in this application space. Dynamic control of metasurface pixels forms a phased-array that could be utilized for ultra-fast steering and reshaping of laser beams and beam modulation for dynamic aberration corrections at switching rates well beyond the state-of-the-art. The ultrathin thickness of a metasurface makes it ideal for ultrafast electro-optical control (up to MHz-GHz switching speeds), which could have far-reaching implications for advancing the speed and beam quality capabilities of laser-based technologies such as additive manufacturing, directed energy, light detection and ranging technology (LIDAR), and free-space optical communications. Such a platform offers clear advantages over mechanical-based systems, enabling random access pointing, inertialess operation, and orders of magnitude speed improvement. 

Our results support the feasibility of this approach, as the allowable powers before damage of the conductive materials in the structure are relevant to the application space. The study also suggested that a further, in-depth investigation is required for the laser damage resilience, including additional, potential failure modes, under thermal management as well as other aspects of the design (e.g., directed light efficiency, losses), and other material systems to be considered for device performance optimization.

Mission Impact

A no-moving-part, ultrafast laser beam steering and arbitrary reshaping technology based on electro-optically modulated metasurfaces has the potential to revolutionize laser-based technologies such as additive manufacturing, directed energy, adaptive optics, LIDAR, and free-space optical communications. Thus, this research supports multiple missions at Lawrence Livermore National Laboratory, including the Laboratory's core competency in lasers and optical science and technology.