Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Dennis W. Prather, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

In this thesis, we use E-Beam lithography to finish the process of DBR laser, 2D Photonic crystal, and Metallic nanoelectrodes. We use the new E-Beam system to define array patterns. By this test, we obtain the minimum linewidth of 50nm, and the maximum working range is 250£gm*250£gm. We fabricated the 2D photonic crystal microcavity and DBR laser on the InGaAs/InAlGaAs which was grown by molecular beam epitaxy (MBE) on InP substrate. For the DBR laser, the length of Multi-mode Interference (MMI) was 90£gm to satisfied the emission wavelength and optical modes. We apply a coupled DBR reflector on both sides of MMI. The mirror width was 361nm and the air gap was 388nm. For the 2D photonic crystal (2D PhC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 1137nm and 456nm, respectively. The TE-mode photonic band gap of this structure is corresponding to wavelength range in 1517.01 nm~1617.81 nm. We leave a single defect in the 2D PhC to form 2D PhC microcavity and the corresponding defect modes are 1546.32nm and 1547.74nm. The Micro-PL measurement shows that a defect mode at 1547nm (a/£f=0.74), a surface state at 1351nm (a/£f=0.85), and a standing wave at 1480nm (a/£f=0.78). The maximum Q value is about 400 for the defect mode.

In this thesis, planar photonic crystals for optofluidic biosensing applications are analyzed. Planar photonic crystals are optically resonant structures which possess modal characteristics which can be exploited for biosensing applications. Sensing is achieved by detecting changes in refractive index due to analyte interactions in a sampled fluid. This work describes a broad study of photonic crystal slab sensors, with special consideration to biosensing. Outlined are considerations pertaining to sensing figures of merit, device fabrication, and performance. Results of simulations and device characterization indicate that planar photonic crystals possess sensing attributes similar or better than existing optically resonant refractive index sensors, such as surface plasmon resonance, grating, and interferometric waveguide sensors. Additionally, these photonic crystals can be patterned in large-areas which enable a simple light coupling scheme. All considered, their appeal as a biosensing solution is justified in the area of in vitro diagnostics.

Photonic crystals (PC) are periodic structures that dictate the behavior of electromagnetic radiation and can be one-dimensional, two-dimensional or three-dimensional (3D). A 3DPC was modeled and fabricated based on a three-layer design resulting in a face centered cubic structure. Different simulation methods were used to show the existence of a complete 3D bandgap, and were verified experimentally by obtaining transmission measurements in several directions. A prototype of the structure was fabricated using ECCOSTOCK HiK high dielectric sheets (dielectric of 12) and machined using a computer and numerical controlled mill. Experiments to test this structure were performed in an anechoic chamber making use of a network analyzer, a pair of horn antennas, collimating lenses, and a track for alignment. Free-space Thru-Reflect-Line measurements were taken between 10GHz and 15GHz to obtain the transmission through the prototype. Finally, a defect layer was added to the structure at different locations and localized modes observed.

In this thesis, planar photonic crystals for optofluidic biosensing applications are analyzed. Planar photonic crystals are optically resonant structures which possess modal characteristics which can be exploited for biosensing applications. Sensing is achieved by detecting changes in refractive index due to analyte interactions in a sampled fluid. This work describes a broad study of photonic crystal slab sensors, with special consideration to biosensing. Outlined are considerations pertaining to sensing figures of merit, device fabrication, and performance. Results of simulations and device characterization indicate that planar photonic crystals possess sensing attributes similar or better than existing optically resonant refractive index sensors, such as surface plasmon resonance, grating, and interferometric waveguide sensors. Additionally, these photonic crystals can be patterned in large-areas which enable a simple light coupling scheme. All considered, their appeal as a biosensing solution is justified in the area of in vitro diagnostics.

Photonic crystals (PC) are periodic structures that dictate the behavior of electromagnetic radiation and can be one-dimensional, two-dimensional or three-dimensional (3D). A 3DPC was modeled and fabricated based on a three-layer design resulting in a face centered cubic structure. Different simulation methods were used to show the existence of a complete 3D bandgap, and were verified experimentally by obtaining transmission measurements in several directions. A prototype of the structure was fabricated using ECCOSTOCK HiK high dielectric sheets (dielectric of 12) and machined using a computer and numerical controlled mill. Experiments to test this structure were performed in an anechoic chamber making use of a network analyzer, a pair of horn antennas, collimating lenses, and a track for alignment. Free-space Thru-Reflect-Line measurements were taken between 10GHz and 15GHz to obtain the transmission through the prototype. Finally, a defect layer was added to the structure at different locations and localized modes observed.

This work presents a novel loss-reduced photonic liquid-crystal fiber (PLCF) using the non-contact photo-alignment method. The photo-excited and adsorbed azo dye on the capillary surface of a PLCF induces uniform and highly ordered orientation of the LC. The anchoring force of the photo-alignment effect is combined with that generated by surface boundary conditions of the photonic crystal fiber (PCF). Transmission loss resulting from LC scattering can be reduced from -2.8db/cm to -1.3db/cm within 10min. This photo-induced alignment yields a permanent boundary for the LC in the PCF that reduces scattering loss, and can be further modulated by electrical fields. The electrical tunable effect and fast dynamic response of the photo-aligned PLCF are also presented. This low-loss PLCF can be applied conveniently in various PLCF devices.

In this thesis, we fabricated the 2D photonic crystal and modified 1D photonic crystal microcavity on the InGaAs/GaAs substrate by E-beam lithography. The wafer are grown by molecular beam epitaxy (MBE) on GaAs substrate. The active layer consists of six InGaAs quantum wells at 1050nm emission wavelength. For the 1D photonic crystal microcavity (DBR laser),we changed the cavity shape and length to match the mode of light in the cavity. It can increase the reflectivity of the laser. In our simulations, we scanned different cavity length and found the corresponding data. We designed two and three pairs of DBRs formed on the edge of laser cavity, respectively. The cavity length is 121µm and the mirror width is 230nm and the air gap is 263nm. For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 742nm and 304nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1026nm ~ 1089nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1051.58nm¡B1053.39nm and 1054.87nm. In addition, we reduced the air columns around the cavity and simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process.

In this thesis, we fabricated the 2D photonic crystal microcavity and laterally coupled distributed feedback laser on InGaAs/InAlGaAs wafers by E-beam lithography. We also fabricated the 2D photonic crystal microcavity on the InGaAs/GaAs substrate at 980nm emission wavelength. The wafer are grown by molecular beam epitaxy (MBE). For the laterally coupled distributed feedback laser (LC-DFB laser) , we changed the grating shape and length to form proper grating, and it will make constructive diffraction and coupling. We design the mirror width is 180.55nm and the air gap is 541.65nm. For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 1139nm and 456nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1522.72nm~1617.89nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1549.23nm and 1550.08nm. We have simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process. Also, we can use the same method to fabricate 980nm photonic crystal.

Because of the fast growing in communications, the quality of signal transmission in optical fiber becomes very important. Concurrently, photonic crystal fiber (PCF) consisting of a central defect region surrounded by multiple air holes is attracting much attention in recent years because of its unique properties, such as full photonic bandgaps, wideband, dispersion, endlessly single mode and birefringence, etc. This thesis is mainly focused on the development of the photonic band structures and propagation properties of PCF. And we propose a novel ideal about 3-D PCF, which can be fabricated using the laser heated pedestal growth (LHPG) method. In the thesis, we study the optical properties of 2-D and 3-D PCFs made by Pyrex using the software RSoft. From the result of simulation, the 2-D out-of-plane bandgaps for a hexagonal close packed structure appear between the air filling fraction range from 0.30 to 0.88 for the incident light of wavelength range from 0.7 to 1