Keywords
Diffraction, Femtosecond lasers, Nonlinear optics, Optical materials
Abstract
Since the first demonstration of femtosecond laser written waveguides in 1996, femtosecond laser direct writing (FLDW) has been providing a versatile means to fabricate embedded 3-D microstructures in transparent materials. The key mechanisms are nonlinear absorption processes that occur when a laser beam is tightly focused into a material and the intensity of the focused beam reaches the range creating enough free electrons to induce structural modification. One of the most useful features that can be exploited in fabricating photonic structures is the refractive index change which results from the localized energy deposition. The laser processing system for FLDW can be realized as a compact, desktop station, implemented by a laser source, a 3-D stage and focusing optics. Thus, FLDW can be readily adopted for the fabrication of the photonic devices. For instance, it has been widely employed in various areas of photonic device fabrication such as active and passive waveguides, couplers, gratings, opto-fluidics and similar applications. This dissertation describes the use of FLDW towards the fabrication of custom designed diffractive optical elements (DOE’s). These are important micro-optical elements that are building blocks in integrated optical devices including on-chip sensors and systems. The fabrication and characterization of laser direct written DOEs in different glass materials is investigated. The design and performance of a range of DOE’s is described, especially, laser-written embedded Fresnel zone plates and linear gratings. Their diffractive efficiency as a function of the fabrication parameters is discussed and an optimized fabrication process is realized. The potential of the micro-DOEs and their integration shown in this dissertation will impact on the fabrication of future on-chip devices involving customized iv DOEs that will serve great flexibility and multi-functional capability on sensing, imaging and beam shaping.
Notes
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Graduation Date
2009
Semester
Fall
Advisor
Richardson, Martin
Degree
Doctor of Philosophy (Ph.D.)
College
College of Optics and Photonics
Degree Program
Optics
Format
application/pdf
Identifier
CFE0002958
URL
http://purl.fcla.edu/fcla/etd/CFE0002958
Language
English
Release Date
June 2013
Length of Campus-only Access
None
Access Status
Doctoral Dissertation (Open Access)
Subjects
Dissertations, Academic -- Optics and Photonics, Optics and Photonics -- Dissertations, Academic
STARS Citation
Choi, Jiyeon, "Femtosecond Laser Written Volumetric Diffractive Optical Elements And Their Applications" (2009). Electronic Theses and Dissertations. 1513.
https://stars.library.ucf.edu/etd/1513