Date of Graduation
Statler College of Engineering and Mineral Resources
Lane Department of Computer Science and Electrical Engineering
Lawrence A. Hornak.
Photonic Crystals (PCs) have been the subject of intense study from their inception. These structures provide precise control of optical transmission properties through the choice of their periodic lattice parameters and materials with which they are fabricated. The sensitivity of optical properties of photonic crystals to the changes in refractive index at one or more lattice sites makes these structures potentially very attractive devices for developing a biosensor. Very small changes in the refractive index of one or more defect sites can be sensed accurately using these nano size structures. This work deals with the modeling and theoretical evaluation of the sensitivity of PC defect transmission states to the changes in refractive index of single and cluster defects. The band gap shifts as a function of the change in different parameters for a 2-D triangular lattice of holes in silicon and GaN were explored. The shifts in the optical transmission with change in refractive index of one to seven defects were calculated using MPB (MIT Photonic Bands) and Optiwave FDTD tools and analyzed. Efforts defining the fabrication process for PC structures were also outlined. Optimization of E-beam lithography to write these patterns in PMMA was also demonstrated. Patterns of 200nm radius with lattice constant of 500 nm in PMMA 495 A2, and patterns of 300nm radius with 1 micron lattice constant were optimized in PMMA 950 A4.
Paturi, Naveen Kumar, "Analysis of photonic crystal defects for biosensing applications" (2006). Graduate Theses, Dissertations, and Problem Reports. 1783.