Telecom-range Lasing in InP/InGaAs Nanoridges

Abstract
Semiconductor nanolasers directly grown on silicon substrates are ideal light sources for silicon-based photonic integrated circuits, benefiting from an ultra-small footprint and high scalability. However, constructing a compact on-chip laser source that covers a wide emission range is still challenging, especially for data-communication applications in the near-infrared region. This thesis presents a comprehensive study of in-plane InP/InGaAs nanolasers with a room temperature emission range fully covering the telecom band. Both the transferred nanowire lasers and on-chip nanoridge lasers are investigated through extensive theoretical studies and simulations. With highly ordered and low defect nanoridges, strong lasing at a low threshold is experimentally demonstrated under optical excitation. The wavelength selectable lasing phenomena are also studied in simple FP nanolaser cavities and the more sophisticated DBR integrated nanolasers. Through the mode and loss analyses, the mechanisms for controlling nanolaser emission wavelengths are revealed. The wavelength tunability schemes are also supported by the experimental realization of coarse lasing mode adjustments. This study paves the way for future advancements in nanolaser technologies, such as complete integration with other optical components in silicon devices and electrically pumped nanolasers.