In this thesis, we successfully fabricated patterned semiconductor substrates, edge-emitting lasers with deeply etched distributed Bragg reflectors (DBRs), two-dimensional photonic crystals (2DPCs) and two-dimensional photonic crystal microcavities (2DPC microcavities) by electron-beam lithography and inductively coupled plasma-reactive ion etching (ICP-RIE). We have obtained a minimum writing linewidth of 50nm and a maximum writing range of 500¡Ñ500µm2 in our electron-beam lithography system. Pitch arrays of 100nm pitch-diameter and 100nm separation have been formed on 100¡Ñ100µm2 semiconductor substrates. The etching depth of patterned Si substrates and patterned GaAs substrates are 50nm and 20nm, respectively. In the design of edge-emitting lasers with deeply etched DBRs, two and three pairs of DBRs were formed on the edge of laser cavity, respectively. To obtain high reflectance at wavelength (£f) = 960nm, 209nm mirror width and 240nm or 720nm air gap were fabricated. In the design of 2DPCs, a triangular array of air columns was adopted. The lattice constant (A) and column radius (R) are 742nm and 327nm, respectively. It has a band gap for TE modes corresponding to wavelength range in 936.45nm~968.85nm. We placed single defect in the 2DPCs to form 2DPC microcavities. In addition, we simulated the photonic band structure of a seven-defect 2DPC microcavity with A = 224nm and R = 56nm. We obtained a monopole defect mode at £f = 959.86nm. To measure 2DPCs and 2DPC microcavities, we have set up a micro-photoluminescence (Micro-PL) spectrum measurement system. We observed the Micro-PL intensity of the 2DPC microcavity is 4.5 times larger than 2DPCs at £f = 960nm in the same pumping power. The 2DPC microcavities show a lasing performance under optical pumping. The threshold power of 2DPC microcavities is 5.13mW~6.81mW at room temperature and decreases to 1.4mW~3.13mW at 15¢J.

The dielectric waveguide component has become a mature industry in these days in making it and understanding how it works. There are many theoretical and numerical methods to solve these waveguide modes. For example, the rigorous vectorial coupled transverse mode integral equation formulation (VCTMIE), finite-difference frequency-domain method (FDFD), vectorial beam propagation method (VBPM) and modal expansion method with simple bases (MEMSB)¡Ketc. With the exception of the MEMSB method and the alike, all these methods work very hard to handle interface boundaries and many require many terms meet the convergence requirements. In this thesis, we propose a rigorous modal expansion method based on a set of orthogonal transverse magnetic bases to analyze arbitrarily profiled 2-D cylindrical dielectric waveguides. First, we expand the mode field solution of a general multi-layered waveguide by linear combination of 1D homogeneous solutions. Magnetic and components are chosen for its continuity property across the material interface. The choice of Magnetic field over electric field also reduces the number of terms and minimizes the Gibb¡¦s phenomenon. Our new vector bases eliminate the numerical difficulty of working with the singular term of the cylindrical differential operators. When compared with the results using simple bases, we further reduce one quarter of terms without loosing any accuracy. Although the process of deriving the formulation of this vector cylindrical basis expansion technique is complex because Bessel functions and their derivatives are involved, the resulting matrix eigenvalue-eigenvector equation is much simpler than that of the simple bases and the new the result is also more accurate. We also extended the analysis to study the 2-D cylindrical dielectric waveguide problem.

Includes bibliographical references (p. 155-159).

Photonic crystals have the capability to control electromagnetic waves due to the existence of photonic bandgap. The devices based on photonic crystal structures usually have the advantage of substantial size reduction compared to their conventional counterparts, which may lead to miniaturization and large-scale integration of optical and optoelectronic devices.In this dissertation, several novel optical devices based on photonic crystals are designed and analyzed, including a compact power splitter, a compact polarizing beam splitter, an optical intersection of nonidentical optical waveguides, and a single mode coupled resonator optical waveguide. The simulation results show superior advantages compared to their conventional counterparts. In addition, a new fabrication method based on combining a custom-built blue laser writer and the technique of optical holography is developed for the purpose of mass production of useful photonic crystal devices.

The design and characterization of both electromagnetic bandgap (EBG) and inter-coupled split-ring resonator (SRR) structures utilized in microwave frequencies were proposed and studied. A new double-stopband EBG structure with a passband region of 14 to 18 GHz was initially constructed by determining the critical structural ratios. To reduce the size of EBG structure, a novel tapered array pattern was introduced. The structural period, the number of slot, and the length of slot were examined and a strong correlation was found between the lowpass cutoff frequency and the center slot length. Non-linearly tapered configuration was applied to enhance the filter performance and its size was only 57% of the conventional EBG structure. Inter-coupled SRR was also examined and utilized as a bandpass filter when it is implemented on the microstrip line for the first time. It was found that the proposed structure can provide a fractional bandwidth of over 68% with an insertion loss of 0.81 dB in the passband region with a device size of 15.5 mm. / Chemical bath deposited Cadmium Sulfide (CdS) thin film was applied to the microwave structures to construct switchable filters. The illumination-sensitive CdS thin film's sheet resistance has been demonstrated to be able to switch from 300 to 109 O/square. With the proposed "conductive-islands" implementation, switching of EBG structure's transmission coefficient (S21) was achieved from 31.3 dB to 5.6 dB at 13 GHz. The inter-coupled SRR structure also showed a S21 switching response from 19 dB to 1.5 dB at 5 GHz. Therefore, optically controlled microwave filters were successfully constructed and realized. / Critical contributions in the field of microwave periodic structures are the characterization and the construction of double-stopband structure, linearly and non-linearly tapered array structures, and inter-coupled SRR structures. Vital characteristics and advantages discovered include wide stopband, reduced size, and large fractional bandwidth. Chemical bath deposited CdS thin films were studied to achieve an ultra low sheet resistance and high photosensitivity. Important applications associated with these structures are microwave lowpass/bandpass filters and optically controlled filters.

Nonlinear optical phenomena associated with high-order soliton breakup in photonic crystal fibres and squeezed state generation in three dimensional photonic crystal microcavities are investigated. In both cases, the properties of periodically patterned, high-index contrast dielectric structures are engineered to control the dispersion and local field enhancements of the electromagnetic field. Ultra-short pulse propagation in a polarization-maintaining microstructured fibre (with 1 um core diameter and 1.1 m length) is investigated experimentally and theoretically. For an 80 MHz train of 130 fs pulses with average propagating powers in the fibre up to 13.8 mW, the output spectra consist of multiple discrete solitons that shift continuously to lower energies as they propagate in the lowest transverse mode of the fibre. The number of solitons and the amount that they shift both increase with the launched power. All of the data is quantitatively consistent with solutions of the nonlinear Schrodinger equation, but only when the Raman nonlinearity is treated without approximation, and self-steepening is included. The feasibility of using a parametric down-conversion process to generate squeezed electromagnetic states in 3D photonic crystal microcavity structures is investigated for the first time. The spectrum of the squeezed light is theoretically calculated by using an open cavity quantum mechanical formalism. The cavity communicates with two main channels, which model vertical radiation losses and coupling into a single-mode waveguide respectively. The amount of squeezing is determined by the correlation functions relating the field quadratures of light coupled into the waveguide. All of the relevant model parameters are realistically estimated using 3D finite-difference time-domain (FDTD) simulations. Squeezing up to ~20% below the shot noise level is predicted for reasonable optical excitation levels. To preserve the squeezed nature of the light generated in the microcavity, a unidirectional coupling geometry from the microcavity to a ridge waveguide in a slab photonic crystal structure is studied. The structure was successfully fabricated in a silicon membrane, and experimental measurements of the efficiency for the signal coupled out of the structure are in good agreement with the result of FDTD simulations. The coupling efficiency of the cavity mode to the output channel is ~60%.

Recently photonic crystals with a three - dimensional ordered structure with periodicity of the optical wavelength have attracted attention from both fundamental and practical points of view. Control of electromagnetic waves flow in photonic crystals was discussed. The application of photonic crystals is to create tunable band gap materials especially in visible spectra region, where the gap could be controlled by an external parameter. Opal crystal films have been fabricated on solid substrates with a horizontal deposition method. We have studied transmission spectra of synthetic opal, infiltrated with nematic liquid crystal 5CB and demonstrating that the position of the stop band in the visible spectra is shifted to IR wavelength with increasing volume part of 5CB in photonic crystal opal. We show dependence upon stop band position and light incidence angle in bare opal. It is a possibility turning this stop band. Opal filled with LC photonic strength was studied. We demonstrating that photonic strength saturates when was filled about 20% of opal voids.

We have studied inverse opal optical properties. Defects, action on photonic band gab position was discussed. We showed that defect gives us possibility to control light flow in photonic crystal.

Recently photonic crystals with a three - dimensional ordered structure with periodicity of the optical wavelength have attracted attention from both fundamental and practical points of view.Light flow control in photonic crystals was discussed.Opal crystal films have been fabricated on solid substrates with a vertical deposition method.

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: CROW; PBG; PhC; coupled resonator optical waveguide; metamaterials; photonic crystal; Bloch wave; photonic band gap;dynamic waveguide; Brillouin zone; thermal spreading. Includes bibliographical references (p. 84-87).