High-power laser testing of 3D meta-optics

ABSTRACT 3D Meta -Optics are optical components that are based on the engineering of the electromagnetic fields in 3D dielectric structures. The results of which will provide a class of transformational optical components that can be integrated at all levels throughout a High Energy Laser system. This paper will address a number of optical components based on 2D and 3D micro and nano -scale structures and their performance when exposed to high power lasers. Specifically, results will be presented for 1550 nm and 2000 nm spectral bands and power densities greater than 100 kW/cm 2 . Keywords: Spectral filter, resonant structures, high energy laser INTRODUCTION Many applications of modern opti cal systems rely heavily on the ability to customize the output beam of an optical system to fit the application requirements. Applications in telecommunications, for instance, place the operation wavelength at 1.55 µm while medical applications utilize 2. 94 µm to take advantage of water absorption in the skin. Additionally, operation in optical fibers and laser systems typically requires the use of a narrowband spectral selectivity while both narrowband and broadband reflectors have been proposed for vertical cavity surface emitting lasers (VCSELs) [1,2 ]. The beam shape can als o play a vital role in the success of a device. For instance, a Gaussian beam profile may be optimal for investigating high power laser damage, while spatial multiplexing can take advantage of a non -Gaussian beam profile. If the components are to be used a s out -couplers in bulk lasers , the optics must be able to operate at high power densities. As a whole, the ability to fully control the output beam from an optical system across a broad spectral range requires new device geometries. To overcome this divers ity in the element geometry, diffractive and micro -optics have been used [3]. B ased on the ir well -known fabrication process [4], these device geometries have b een used as spectral and spatial filters as well as spectral and spatial beam shaping devices [5].