랩투어도 준비하길...

제   목   Shift-variant optics for 3D imaging
강   사   Prof. George Barbastathis  
소   속   MIT Mechanical Engineering, USA
시   간   2008년 10월 17일 (금요일) 11:00 - 12:00
장   소   제1 신공학관 301동 1121호

Abstract

Traditional optical design emphasizes shift invariance as a method to achieve uniform optical response over the entire field of view. While this approach provides safe design margins for imaging systems operating in two spatial dimensions (2D) such as cameras and microscopes, it is known to be insufficient for three-dimensional (3D) imaging: the extreme example is confocal microscopes, where shift invariance is imposed by a pinhole or optical nonlinearity such as two-photon absorption. We have devised a new approach to implement controllable shift invariance by using the Bragg selectivity property of volume holograms. We have shown, for example, that it is possible to perform confocal-like optical slicing in parallel over several depths and lateral positions by a volume holographic pupil recorded as a series of multiplex exposures. In this seminar, we will review volume holographic optics and compare its physical and image information transfer properties to shift-invariant imaging systems that we have implemented in our laboratory based on digital holography. We will derive a common mathematical framework based on the Hopkins matrix, comment on the maximal imaging quality achievable by shift variant optics, and speculate on the possibility of combined volume holographic and segmented aperture imagers for 3D image capture and display. We will also discuss a more recent proposal to create shift-variant optics as space-variant (non periodic) sub-wavelength patterned high-index contrast dielectrics (artificial materials) that act as gradient index (GRIN) lenses with arbitrary index modulation.

강사이력

George Barbastathis is Associate Professor of Mechanical Engineering at MIT. He received the Diploma in Electrical and Computer Engineering from the National Technical University of Athens in 1993, and the M.Sc. and Ph.D. in Electrical Engineering from Caltech in 1994 and ’97, respectively. Other academic appointments:Post-doctoral Research Associate with the Beckman Institute at the University of Illinois, Urbana-Champaign (1997-99); Visiting Scholar with the School of Engineering and Applied Science at Harvard University (2006-07) and faculty resident in Singapore with the Singapore-MIT Alliance for Research and Technology (SMART) Centre (2008-09.) He has been the recipient of the Nikolaos Kritikos award in Mathematics, the 3M Innovation Award, the NSF Young Investigator Award, and the J. S. W. Kellett award at MIT. His research is centered on the physics and engineering of 3D optical imaging systems based on volume holography and 3D nanostructures with applications to optics, in particular mechanically reconfigurable photonic crystals and non-periodic subwavelength photonic structures with high index contrast.