| The revolutionary achievements on both digital and analog fiber-optic communications have shown their powerful functions and significant influences on our everyday life - from the Internet to cable TV. Semiconductor optoelectronic devices, as major enabling components in the physical layer of the optical communication network, are being explored extensively for various high-speed applications.;Direct modulated semiconductor lasers, particularly vertical-cavity surface-emitting lasers (VCSELs), with their great advantages on cost and size, are attractive for optical data transmission along both analog and digital links. However, these devices have limited modulation performance that prevents them from being widely employed as data transmitters in various communication systems. Other than novel device design and engineering, an alternative technique to help improve the laser modulation properties is optical injection locking, which refers to a state when the frequency and phase of one laser oscillator, known as the slave laser, are locked through the direct coupling to the light injection from another laser oscillator, known as the master laser.;In this dissertation, optical injection locking induced laser dynamics in a VCSEL is investigated in detail both theoretically and experimentally. A hybrid model based on a Fabry-Perot amplifier structure for the VCSEL and the well-formulated injection-locking laser rate equations is established, which can be used to intuitively explain the physics of various experimental phenomena. Systematic experimental study on the modulation characteristics of injection-locked VCSELs is conducted, showing significant performance improvement, such as record resonance frequency > 100 GHz and 3-dB bandwidth of 66 GHz for small-signal modulation, and 10 times chirp reduction and > 10 times transmission distance enhancement for large-signal modulation. A number of intriguing applications are discussed, including a microwave optoelectronic oscillator (0E0), pre-chirp technique for digital data transmission and wavelength-division-multiplexed (WDM) passive optical networks (PONs), all of which appear exceptionally good performance. Finally, future work and projections of the technology are briefly mentioned to encourage further study and development on this research topic. |
