Professor Olav Solgaard
Director of the E.L. Ginzton Laboratory
Department of Electrical Engineering
Stanford University
Professor Solgaard earned his Ph.D. degree from Stanford University in 1992. His doctoral dissertation: "Integrated Semiconductor Light Modulators for Fiber-optic and
Display Applications" described, for the first time, deformable grating light valves. These microphotonic devices were the basis for the establishment of a Silicon
Valley firm that became Silicon Light Machines (SLM), co-founded by Dr. Solgaard in 1994. He served as a consultant and Technology Advisory Board member to SLM, which
was bought by Cypress Semiconductor Corporation in 2000. From 1992 to 1995 he carried out research on optical MEMS as a Postdoctoral Fellow at the University of California,
Berkeley, and in 1995, he joined the Electrical Engineering faculty of the University of California, Davis. His work at UC Davis led to the invention of the
multi-wavelength, fiber-optical switch, which has been developed into commercial products by several companies. In 1999 he joined Stanford University where he is now an
Associate Professor of Electrical Engineering and Director of the E.L. Ginzton Laboratory. Professors Solgaard's research interests include Optical MEMS, Photonic Crystals,
and Atomic Force Microscopy for applications in telecommunication and health care. He has authored more than 250 technical publications and holds 41 patents.
Professor Solgaard came to Stanford with the support of a Royal Norwegian Council for Scientific and Industrial Research Fellowship in 1986 and was named a Terman Fellow
at Stanford for the period 1999-2002. He is a Fellow of the Optical Society of America and member of the Royal Norwegian Society of Sciences and Letters.
Optomechatronics on the Nanoscale
Scaling to nanometer dimensions changes the fundamental design principles of optomechatronic devices and systems. At the nanoscale there is increased coupling between electronic, mechanical, optical, biological, fluidic, and chemical forces, leading to larger complexity in design, but also to new possibilities. Connections and interfaces are also more difficult on the nanoscale. This offers unique challenges and opportunities for optomechatronics. In this talk we will describe the fundamentals of scaling and integration of optomechanical systems to nanometer dimensions and demonstrate practical applications in sensing and microscopy.
Professor Pramod Rastogi
Applied Computing and Mechanics Laboratory
EPFL
Professor Rastogi received his MSc degree from the University of Lucknow, MTech degree from the Indian Institute of Technology Delhi,
and doctorate degree from the University of Franche Comté in France. His research activities are principally in the area of holographic interferometry, speckle metrology,
fiber optics sensors, phase shifting and moiré. He is the author or coauthor of more than 170 scientific papers of which more than 130 are published in peer-reviewed archival
journals. He is also the author of book chapters, Encyclopaedia articles, and has edited several books in the field of optical metrology:
- Holographic interferometry-Principles and Methods, Springer-Verlag, 1994;
- Optical Measurement Techniques and Applications, Artech Book House, 1998;
- Photomechanics, Topics in Applied Physics Series, Vol. 77, Springer-Verlag, 2000;
- Trends in Optical Non-Destructive Testing and Inspection, Elsevier, 2000; and
- Digital Speckle Pattern Interferometry and Related Techniques, John Wiley & Sons, 2001.
Since, March 1999, Professor Rastogi is also the co-editor-in-chief of the International Journal of Optics and Lasers in Engineering, Elsevier, London.
Subspace based methods for phase estimation in interferometry
Phase measurement in an interferometry has been a topic of immense interest for quantifying various physical parameters of interests such as displacement, deformation,
or shape of an object under investigation. Advances in optical configurations have enabled measurement of multiple phase information in few specialized configurations,
for instance, in holographic moiré. Several approaches have been employed to measure phase and one such approach based on subspace-based method has proved to be efficient
to measure physical parameters of interest. These methods primarily measure the phase step imparted to the piezoelectric device placed in path of one of the beams in an
interferometry setup, and, these techniques also exhibit the capability of simultaneously measuring dual phase steps of two piezoelectric devices, in the configuration
involving four-beam interferometry. Measurement of phase in two-beam interferometry or multiple phases in four-beam interferometry using piezoelectric devices is susceptible
to several systematic and random sources of errors. In such cases, these methods have shown to be effective. This talk presents an overview of subspace-based methods for
the estimation of phase information in interferometry. The talk summarizes various aspects such as accuracy of phase step estimation, data frames, computational cost, and
limitations in the retrieval of interfered phases.
Professor Michael Y.Y. Hung
John F Doge Professor Emeritus
Oakland University
Rochester, Michigan, USA
Prof. Michael Hung received his PhD in theoretical and applied mechanics from the University of Illinois. He has recently retired after forty years of academic career. He is presently John F. Dodge Professor Emeritus at Oakland University. Before his retirement, he was Chair professor and Head of the Manufacturing Engineering and Engineering Management Department at City University of Hong Kong. Prof. Hung has multi-disciplinary research experiences including: nondestructive testing, experimental stress analysis, design optimization, noise and vibration, composite materials, electronic packaging, 3D computer vision and optical metrology. He has published over 250 journal and conference papers, seven book chapters, six patents and numerous industrial reports. He is a pioneer in industrial applications of holography and is the inventor of shearography that has been endorsed by FAA for nondestructive inspection of aircraft structures, particularly, aircraft tires. He has won numerous professions awards including the prestigious B.J. Lazan award for "outstanding contribution in experimental mechanics". Prof Hung is a fellow of SEM (Society for Experimental Mechanics) and a Fellow of SPIE (Society of Photo-Optical Instrumentation Engineers).
Shearography and Applications in Measurement and Nondestructive Evaluation
This talk will review shearography and its applications in measurement and nondestructive testing. Shearography is an electro-optical technique for full-field and non-contact measurement of object deformation. It was invented to overcome several limitations of holograph by eliminating the requirement of a reference beam. The technique enjoys the advantages of simplified and robust setup, reduced laser coherence length requirement, and less demanding in environmental stability. Consequently, it is employable in industrial settings and has received wide industrial acceptance. (Note that holography was invented by Prof Dennis Gabor and he was awarded a Nobel Prize in Physics for the invention.)
In the setup, the test object is illuminated by an expanded laser beam and imaged by a digital image-shearing camera. In the measurement, two shearing images, corresponding to deformed and undeformed state of the object, are digitized. The optical phase difference between the two images depicts the object surface deformation (displacement or strain). An algorithm is developed to allow the phase difference to be precisely and rapidly determined.
Despite being a relative young technique, it is rapidly emerging as an important nondestructive inspection tool for industrial applications. It detects flaws in an object by looking for flaw-induced deformation anomalies, and it is 1000 times faster than ultrasonic techniques. Currently the rubber industry is routinely using shearography for evaluating tire quality, and the aerospace industry has adopted it for nondestructive testing of aircraft structures. In particular, FAA has endorsed the technique for inspecting aircraft tires. Since the adoption, aircraft accidents due to tire failures have been virtually eliminated. Other applications of shearography include: strain measurement, design optimization, material characterization, residual stress evaluation, leak detection, vibration and 3D shape measurement. The recent success in extending the technique to nondestructive evaluation of building structures will also be presented.
