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.