[{"key":"dc.contributor.author","value":"Cowan, Allan Ralph","language":null},{"key":"dc.date.accessioned","value":"2009-12-23T18:23:36Z","language":null},{"key":"dc.date.available","value":"2009-12-23T18:23:36Z","language":null},{"key":"dc.date.issued","value":"2004","language":null},{"key":"dc.identifier.uri","value":"http:\/\/hdl.handle.net\/2429\/17251","language":null},{"key":"dc.description.abstract","value":"This thesis describes theoretical and experimental research on the nonlinear\r\nresponse of high refractive index contrast (HRIC) optical microcavities. An\r\nintuitive, numerically efficient model of second harmonic reflection from two\r\ndimensional (2D), planar photonic crystals made of sub-wavelength thick,\r\nnon-centrosymmetric semiconductors is developed. It predicts that appropriate\r\n2D texture can result in orders of magnitude enhancement of the\r\nreflected second order signal when harmonic plane waves are used to excite\r\nleaky photonic crystal eigenmodes. Local field enhancement in the textured\r\nslab, and other physical processes responsible for these enhancements are\r\nexplained.\r\n\r\n\r\nA different formalism is developed to treat the Kerr-related bistable response\r\nof a 3D microcavity coupled to a single mode waveguide. This model\r\npredicts that optical bistability should be observed using only milliwatts of\r\npower to excite a cavity fabricated in Al\u2080.\u2081\u2088Ga\u2080.\u2088\u2082 As, having a quality factor\r\nof Q = 4000 and a mode volume of 0.05 \/\u03bcm\u00b3. Two-photon absorption is\r\nshown to only slightly hinder the performance in Al\u2080.\u2081\u2088Ga\u2080.\u2088\u2082As. By including\r\nnonresonant downstream reflections in the model, novel hysteresis loops\r\nare predicted, and their stability is analyzed.\r\nA coupled waveguide-microcavity structure is fabricated by selectively cladding a silicon ridge-Bragg grating waveguide with photoresist. Threedimensionally\r\nlocalized optical modes are realized with Q values ranging\r\nfrom 200 to 1200, at ~ 1.5 \u03bcm. Using 100 fs pulses, the transmission spectra\r\nof these structures is studied as a function of input power. The output\r\npower saturates when the cavity mode and pulse centre frequencies are resonant,\r\nand the output exhibits super linear growth when they are appropriately\r\ndetuned. These results are explained in terms of the filtering action\r\nof the microcavity on the nonlinear spectral distortion of the input pulse as\r\nit propagates through the waveguide. PbSe nanocrystals are deposited on a\r\nmicrocavity in order to enhance its nonlinear response. Asymmetrical spectral\r\nbroadening and saturation of the transmitted power is observed with\r\n~ 10 000 photons in the cavity. A time-dependent third order model of the\r\nmicrocavity's impulse response is developed to describe this behaviour.\r\nThis work contributes to a quantitative understanding of how HRIC dielectric\r\ntexture can be engineered to obtain useful nonlinear optical responses\r\nat moderate power levels.","language":"en"},{"key":"dc.language.iso","value":"eng","language":"en"},{"key":"dc.publisher","value":"University of British Columbia","language":null},{"key":"dc.rights","value":"For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https:\/\/open.library.ubc.ca\/terms_of_use.","language":null},{"key":"dc.title","value":"Nonlinear optics in high refractive index contrast photonic crystal microcavities","language":"en"},{"key":"dc.type","value":"Text","language":null},{"key":"dc.degree.name","value":"Doctor of Philosophy - PhD","language":"en"},{"key":"dc.degree.discipline","value":"Physics","language":"en"},{"key":"dc.degree.grantor","value":"University of British Columbia","language":null},{"key":"dc.date.graduation","value":"2005-05","language":"en"},{"key":"dc.type.text","value":"Thesis\/Dissertation","language":"en"},{"key":"dc.description.affiliation","value":"Science, Faculty of","language":null},{"key":"dc.description.affiliation","value":"Physics and Astronomy, Department of","language":null},{"key":"dc.degree.campus","value":"UBCV","language":"en"},{"key":"dc.description.scholarlevel","value":"Graduate","language":"en"}]