Development of light emitting and detecting devices for photonic integrated circuit

Abstract

Over the last decade, we have seen enormous increase in the information capacity of data communication. The expansion of such information bandwidth and related energy consumption is expected to continue in an unprecedented way for the foreseeable future. Electronics alone, however, is not enough to process this tremendous amount of information with reasonable power consumption and space constraints. Integrated photonic devices offer an exciting solution to this problem by utilizing faster and low power optical signals in conjunction with well-established semiconductor fabrication technologies. In this dissertation, I demonstrated various light emitting and detecting devices, which are important component for integrated optical communications. In the first part, I demonstrate the subwavelength-scale metallodielectric light source. I observe cavity effects when a semiconductor nano-block is on a metal substrate, and the bottom metal substrate significantly enhances a spontaneous emission rate. Introducing an upper metal layer allows the metallodielectric nano-cavity to reach lasing condition with subwavelength-scale effective mode volume (~0.0064 cubic wavelengths) and physical volume (~0.017 cubic wavelengths). I also investigate a thermal issue of small laser with considering temperature dependent characteristics of the metallodielectric nano-cavity. In the second part, I introduce hybrid metal-dielectric cavity to reduce vertical radiation loss. In the first chapter, bottom metallic mirror plane was combined with photonic-crystal bandedge laser. Lateral confinement of PhC and vertical confinement of bottom metal plane allow room temperature operation with restricted 2D PhC layers. In the second section, hybrid metal-circular bragg reflector cavity was demonstrated. Proper combination of in-plane photonic bandgap from circular Bragg reflector and vertical antiresonances from bottom mirror plane provides lasing condition with a few Bragg reflector. In the third part, electrically-driven metal-dielectric-metal (MDM) photonic device was demonstrated for the practical applications. In the first, second and third chapter, MDM photonic devices were combined with metal-insulator-metal (MIM) waveguide for plasmon link and its elements. Firstly, plasmon source and detector were characterized, and then on-chip scale plasmon signal transmittance was demonstrated. In the last chapter, electrically driven nano/micro cavity was studied for the densely integrated photonic device. In the last part, I introduce facile metal-oxides synthesis methods for application of optoelectronics. By using focused and pulsed laser illumination as a local heat source, rapid and self-limited synthesis of various metal oxide semiconductor materials is achieved with precise spatial and temporal control. Its distinctive characteristics allow highly localized real-time metal-oxides synthesis between separated metal structures, which provides mechanical joining as well as electrical connection and photoconductivity. The growth time for a micrometer-sized metal oxide bump is educed to seconds from hours in the conventional hydrothermal technique. Proposed methods can easily synthesize metal-oxides on an electronics based circuit, and will open up integration of metal-oxides semiconductor based light sensor and light emitting device with the electronics.