Metallo-dielectric Nanolasers for Dense Chip-scale Integration

Metal-clad nanolasers have recently become excellent candidates for light sources in densely-packed chip-scale photonic circuits. This dissertation focuses on the metallo-dielectric type of metal-clad nanolasers. To understand the quantum effects in nanoscale semiconductor lasers, a formal treatment of the Purcell effect, which describes the modification of the spontaneous emission rate by a sub-wavelength cavity, is first presented. This formalism is developed for the transparent medium condition, using the emitter-field-reservoir model in the quantum theory of damping, and its utility is demonstrated through the analysis and design of nanolasers. Next, the design, fabrication, and characterization of metallo- dielectric lasers under electrical pumping are discussed. To achieve nanolasers with optimal performance, different active medium materials are compared, and, it is shown that that the commonly suggested multiple quantum well (MQW) structure may not be suitable for nanolasers. The interplay of various temperature-dependent parameters, as well as their effects on optical mode and emission characteristics are subsequently studied. Building on this knowledge, electrically pumped metallo-dielectric nanolasers amenable to room temperature operation are designed, with the focus on minimizing thermal heating and threshold gain. Preliminary experimental validation of the design is shown. Finally, future research directions toward high efficiency nanolasers and their integration into chip-scale photonic systems are discussed