Laser direct writing metalens with phase change material and application
Date
2021
Authors
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Publisher
University of Delaware
Abstract
With the further study of phase change materials, more applications have been found to applied in many industries. The idea of photonic integrated circuit has come up as the mature electrical circuit is getting hard to meet demand of higher speed communication. Among various kinds of optical devices, phase change material (PCM) is ideal to be utilized to be tunable devices. The reversible change of phase states provides multiple possibilities for modifying optical signals. In term of imaging, the thickness and weight of conventional lens must be increased to meet the demands of numerical aperture and resolution, so the ideal of ‘flat’ diffraction lens came out. ☐ The light source of laser written diffraction lens is relative with the feature size of reaction between laser and PCM. To focus near-infrared light (wavelength ~= 1550 nm), the feature size of ablation must be limited. So, the dosage process of PCMs is included in this thesis. ☐ This thesis mainly illustrates the laser inscription applications on chalcogenide PCM. Diffraction lens are the dominant devices to be designed. The first two chapters are the background of diffraction lens fabrication designs, which is 1-D lens based on different PCM material. They include Ge2Sb2Te5 films, Al2Se3 and Tellurium flukes. The features of PCM and their reactions with laser will be illustrated in theses chapter. Before the fabrication of the lens, dosage and simulation will be clarified in chapter 3 and 4. In chapter 5, the experimental information of fabrication will be shown here like the setup and optical path of laser. After fabrication, the performance of the designed devices will be evaluated in chapter 6. The final chapter will conclude the devices and their future.
Description
Keywords
Photonic integrated circuit, Phase change material, Optical signals