Browsing by Author "Zhang, Ningyi"

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    Optimal design for a varying environment
    (2002-07) Lapin, Serguei; Nguyen, Xuan Hien; Oh, Jiyeon; Vasiliu, Daniel; Yin, Pei; Zhang, Ningyi; Misemer, David (mentor)
    Lasers are currently used in many processes in which materials are manipulated, including abalation of polymers, cutting of both metals and nonmetals, and annealing of semiconductors. In many applications, the processes include not only changing the material properties but patterning them as well. Computer-generated holograms are diffractive optical elements (DOE) that permit very general changes in phase and amplitude of an incoming wave. By adjusting the local phase function, one can create the desired target intensity in the image plane. The DOE responsible for the phase shifts is called a phase mask. Such optical elements can be used to shape a beam with Gaussian intensity profile into a uniform top hat shape. Although it is now possible to create continuous masks to adjust the phase, the discrete ones are more common and inexpenisve...