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Date: 7 May 2019 (Tue)

Time: 2:30-3:30 pm

Speaker: Prof. Allen Yi, Department of Industrial and Systems Engineering, The Ohio State University

Venue: Room CF401, PolyU  

(This seminar is open to public.)

 

 

Abstract of Talk:Seminar Announcement Allen Yi 20190507V2

In this presentation, high volume manufacturing processes of glass and polymer optics of different scales,In this presentation, high volume manufacturing processes of glass and polymer optics of different scales,ranging from large telescope optics to diffractive optics used in many consumer products are discussed. Forglass materials, due to its intrinsic material properties, it is difficult to produce high precision glass opticsusing conventional manufacturing processes. Precision glass molding, sometimes referred to as PGM, isconsidered a viable alternative. In this process, a glass or plastic preform, usually in the form of gob or diskis heated rapidly above its glass transition temperature and then pressed using two optical mold halves tofinish dimensions followed by a slow cooling/annealing to room temperature. Professor Yi’s research seeksfundamental understanding of glass molding process, from lens forming, to mold making, to molding processmodeling. The scope of his research on this topic also includes work in numerical modeling and experimentalmeasurements of stress and structural relaxation, as well as refractive index variation in molded optics.Manufacturing of precision polymer optics in high volume on the other hand is a much mature technology.However, due to complex behaviors of the polymer melts during molding (most often injection molding),optical characteristics of the molded plastic lenses largely are determined by the molding processes used.Extensive research and development have been conducted to answer these fundamental questions. As partof the presentation, a few examples are also provided.

About the Speaker:

Professor Allen Yi received his Ph.D. in mechanical engineering from Boston University in 1993. HeProfessor Allen Yi received his Ph.D. in mechanical engineering from Boston University in 1993. Heconducted doctoral research under the direction of Professor Thomas Bifano working on an innovativeultraprecision machining process for ceramic mirrors. He subsequently joined Corning Precision Lens as astaff scientist where his main responsibilities included development of advanced manufacturing processesof optical molds for refractive and diffractive lenses. In 2002, he joined The Ohio State University. He waspromoted to associate professor with tenure in 2008 and to full professor in 2012. Professor Yi’s researchactivities have been in the general area of precision engineering with a focus on high volume opticalfabrication, freeform and microoptics fabrication as well as micromachining processes for medical andbiomedical devices. Professor Yi has been a member of the ASPE (American Society for PrecisionEngineering) since 1991. Outside ASPE, he frequently participates in the conferences at EUSPEN and ASPEN.He currently services as the Associate Editor for Advanced Optical Technologies.