报告题目:Investigation of Precision Molding of Chalcogenide Glass Optics
报告人:Dr. Lin Zhang, The Ohio State University
Chalcogenide glass (ChG) is increasingly used in infrared (IR) optical systems owing to its excellent IR optical properties and scalable production using precision glass molding (PGM). This study is aimed to seek scientific and fundamental understanding of ChG in precision glass molding process for precision IR micro-optical fabrication by prediction of optical properties transition, integrating numerical modeling of forming process, and evaluation of the molded freeform optics. Compared with conventional IR materials, germanium-free ChG can be readily molded into precision optics, therefore, providing photonics industry with material candidates for low-cost and high-performance photonics devices.Before widely applications in industry, the major challenges in manufacturing affordable high-quality molded optics, the proposed work will include several key steps:
1. Evaluate the thermoforming mechanism of ChG in PGM. The refractive index variations inside large-aperture IR lenses are predicted by FEM simulation and further evaluated by measuring wavefront changes using an infrared Shack-Hartmann wavefront sensor (SHWFS), while the residual stresses trapped inside the molded lenses were obtained by using a birefringence method.
2. ChG molded micro-optical device fabrication and demonstration. Two typical micro-optical devices are designed and fabricated, including SHWFS based measurement system for evaluating the molded freeform lenses and multi-channel large field-of-view IR artificial compound eyes.
Lin ZHANGis currently pursuing a Ph.D in integrated industry engineering under the advisement of Professor Allen Y. Yi. His work focuses on the mechanism of precision chalcogenide glass molding and its applications on thermal imaging. Infrared camera thermal imaging is an exciting technology that allows the user to ‘see’ heat energy with a device similar (in operation) to a standard camcorder, which expands the ‘visible’ spectrum of the human eye by doing the work our eyes cannot do. It has numerous practical applications, including night vision imaging and thermal detection. Lin has designed and fabricated serval microlens arrays using precision glass molding that dominated the possibility of such method and further enlarged the applications of thermal imaging. Compared to current industry standards, precision glass molding is more suitable for large-volume and low-cost industrial production. Lin has published over 40 technical articles, including more than 35 SCI journal articles and 5 patents.