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 from 1300 nm to 1600 nm. Both the transferred nanowire lasers and on-chip nanoridge lasers are investigated through extensive theoretical studies and simulations. The good optical characteristics of the guiding modes are presented and the TE₀₁ lasing mode is...[ Read more ]

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 from 1300 nm to 1600 nm. Both the transferred nanowire lasers and on-chip nanoridge lasers are investigated through extensive theoretical studies and simulations. The good optical characteristics of the guiding modes are presented and the TE₀₁ lasing mode is identified. With highly ordered and low defect nanoridges, strong lasing at a low threshold of around 40 μJ is experimentally demonstrated under optical excitation. The wavelength selectable lasing phenomena are also studied in simple Fabry-Pérot nanolaser cavities and the more sophisticated Distributed Bragg Reflector integrated nanolasers. The mode and loss analyses reveal that the mechanisms for controlling nanolaser emission wavelengths are mainly a result of the enhancement band-filling effect from the low-dimensional quantum well material. 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.