Steven Gillmer, MechE PhD Student, will be defending his PhD work on Tuesday, April 26th at 10:00 AM. The defense will take place in Hopeman 224, in the MechE Conference Room.
Resolution and Functionality Enhancements in Optical Metrology
Scientific experiments continue to push engineering limits beyond the nano-scale, driving the development of extremely high resolution measurement tools and calibrations as a result. The effective implementation of optical metrology and its associated instrumentation involves a multi-disciplinary approach. This thesis draws from mechanical, electrical, and optical engineering subject areas in order to implement the proposed resolution and functionality enhancements. The discussion will focus on three forms of optical metrology: optical displacement sensing, scatterometry, and interferometric weak measurements. The primary applications of the advancements in optical displacement sensing lie in the measurement and calibration of computer numerical control (CNC) equipment and coordinate measuring machines (CMMs). A novel scatterometry tool will be presented for critical-dimension metrology in the continued sustenance of Moore’s law. Finally, optical displacement sensing and scatterometry will find parallels through weak measurements. Both application areas have potential for vast performance improvements via the measurement of a weak value. A variety of novel concepts and experiments will be presented within these fields of research with the ultimate goal of their dissemination into the manufacturing and semiconductor industries.
Sam Butler successfully defended his MS Thesis, Development of Electronics and Signal Processing for a Displacement Measuring Interferometer Probe for Freeform Optics, on April 14th. Sam’s committee consisted of his advisor, Professor Paul Funkenbusch (MechE), and Professor Qiang Lin (ECE).
Sam has recently accepted a position as a System Engineer at Clerio Vision, Inc., a startup company spun off from the University of Rochester and the labs of Prof. Ellis, Knox, and Huxlin. We wish Sam congratulations and all the best in the future!
Mechanical Engineering MS student, Sam Butler, will defend his MS thesis work on Thursday, April 14th at 3 PM in the Hopeman 224 conference room.
Development of Electronics and Signal Processing for a Displacement Measuring Interferometer Probe for Freeform Optics
The burgeoning field of freeform optical design is currently limited by metrological techniques for validating manufactured designs. State-of-the-art measurement systems do not provide the flexibility, measurement bandwidth, or low measurement uncertainty required for producing freeform optics of the same quality achievable for spherical and aspheric parts. One promising avenue for reaching high-quality metrology is through the use of optical coordinate measuring machines (OCMM). These are 5-axis probing machines that use non-contact, optics-based probes for surface measurement. This research seeks to develop an optical probe with high measurement bandwidth and low measurement uncertainty in a compact form factor that provides linear and angular measurement of the optical surface under test. The probe uses homodyne interferometry in a Michelson configuration for linear displacement sensing, and a lens in combination with a position-sensitive detector in an autocollimation capacity for angular displacement sensing. Development of electronics and signal processing, as well as preliminary measurement results using a prototype probe, will be discussed.
Professor Ellis recently met with Professor Jui-Wen Pan and Dr. Kao-Der Chang who were on a visit to The Institute of Optics Industrial Associates Program from Taiwan and discussed methods for transitioning technology from the university environment to relevant industries. Professor Pan is an Assistant Professor in the Institute of Photonic System at the National Chiao Tung University. Dr. Chang is a Researcher at the Industrial Technology Research Institute (ITRI) in their Mechanical and Systems Research Laboratory. We look forward to potential collaborations in the future!
MechE undergraduate student and PIG member Loudon Blake has been making parts for the practice carillion. His work has been part of the EAS141 Machine Shop course. More details on the project can be found here. Nice work Loudon!
Photograph of the new (left) and old (right) hammer head made by Loudon.
[Photo Credits: J. Adam Fenster/University of Rochester]
The Precision Instrumentation Group has recently grown! As of January 2016, Fenghe Zhong and Elizabeth Fox have joined the group.
Fenghe hails from Wuhan, China from Huazhong University of Science & Technology with a background in opto-electronics. He is currently pursuing his MS Thesis research in The Institute of Optics.
Elizabeth is currently a BS student in Mechanical Engineering at the University of Rochester. She is originally from Chapel Hill, NC and is interested in precision engineering and opto-mechanical design.
Jonathan Ellis, along with researchers at the University of South Carolina and the University of North Carolina at Charlotte have recently had a paper accepted in Precision Engineering. The paper entitled, “Application of the continuous wavelet transform in periodic error compensation,” demonstrates a novel algorithm for the compensation of periodic error for both constant and non-constant velocity motion. Congratulations to first author Chao Lu, a MechE PhD student under Prof. Joshua A. Tarbutton at the University of South Carolina, for his first 1st author journal publication!
The prepress of the paper can be accessed here.
Dr. Tieli Zhang‘s stint at the University of Rochester as a Visiting Scientist in the Department of Mechanical Engineering has ended. We wish Dr. Zhang all the best in the future!
Also, we welcome UR MechE Alumnus Tim Lynch into the group as a MS Student working on Freeform Optics Metrology. Welcome, Tim!
Xiangzhi Yu, mechanical engineering PhD student, is defending his PhD Thesis Proposal today, Monday, December 14 at 1 PM. The location for his Proposal Defense is in Hopeman 224.
Precision linear stages provide the basic movement for many nanotechnology systems such as lithography stages, biological scanning systems, and nanofabrication positioning systems. All these systems require precise position sensing for feedback control and extensive calibration procedures to achieve the required accuracy. In this proposal, a compact state-of-the-art multidegree of freedom optical metrology system is presented which will enable fast, accurate calibration and error mapping of multiple axes simultaneously. The working principle for each degree-of-freedom measurement is shown and system-level integration will be investigated to evaluate the overall performance. In addition, the proposed system will significantly mitigate the temporal, dynamic, location and Abbe errors during calibration process. In the end, a refractometer which enables both absolute refractive index of air sensing and tracking based on variable length vacuum cell is presented, which is essential for ultra-precision interferometry measurements under atmospheric conditions.
Steve Gillmer, MechE PhD student, was awarded the 2015 Carl Zeiss Student Scholarship at the recent American Society for Precision Engineering Annual Meeting. This award includes the ASPE Annual Meeting registration fee, four tutorial fees, travel expenses, and lodging to the Annual Meeting. In addition, the scholarship provides for travel and lodging to Maple Grove, Minnesota to visit Carl Zeiss Industrial Metrology. Steve is the third recipient of the Carl Zeiss Student Scholarship awarded through ASPE.
Photo: Steve with Dr. Marcin Bauza of Carl Zeiss IMT and Dr. Byron Knapp of Professional Instruments and ASPE President being awarded the scholarship at the ASPE Annual Meeting in Austin, TX.