Additive Manufacturing of Multi-dimensional Diffractive Elements
A diffractive optical element (DOE) can manipulate the light to generate the desired profile or shape with micro-structure patterns to alter the phase of the passed light. They are widely used and applied in various experimental and commercial systems because of their complex light manipulation capability, compact and lightweight designs, and holographic imaging ability.
There are many ways to make DOEs but it is hard to manufacture high precision DOEs with low cost, simple procedures, and capability for 3D structures. The current fabrication of DOEs mainly focuses on nanofabrication techniques, especially photolithography. These methods have a very high resolution and accuracy in nanoscale, but usually require expensive equipment and are limited to planar structures. Additive manufacturing is a low-cost, layer-based manufacturing technique, which is very strong in forming 3D structures. However, the resolution and accuracy of most 3D printers are limited to a micrometer scale, which is not small enough for the diffraction of visible light.
This research aims to understand the mechanics of modulating the phase of DOEs and improve the manufacturing process of 3D printing to achieve better resolution. Two Photon Polymerization (TPP) and Vat Photopolymerization (VPP) 3D printing techniques were investigated and improved to fabricate application-driven designs from 1D to 2D structures. Different strategies and methods such as drop coating, design of lattice structure, and exposure time controlling, were developed to manipulate the physical structure and material properties to control the phase modulation of DOEs. The results pave the way for the future application of 3D printing to fabricate complicated 3D DOEs.
History
Degree Type
- Doctor of Philosophy
Department
- Engineering Technology
Campus location
- West Lafayette