The More The Brighter: Coupling and Emission Tunability in High-beta Telecom-band Semiconductor Nanolasers
- Author(s): Deka, Suruj
- Advisor(s): Fainman, Yeshaiahu
- et al.
The emergence of nanolasers over the past two decades has helped enable a plethora ofnovel applications such as optical communications, on-chip interconnects, sensing and superresolution imaging. Particularly for the field of computing/communication, nanolasers have become an intriguing area of research as photonic integrated circuits (PICs) of the future would require nanoscale light sources. To that end, nanolasers based on a variety of architectures and underlying physics have been demonstrated in the literature. Metallo-dielectric nanolasers (MDNLs) are particularly attractive since they combine the advantages of ultrasmall footprints and low thresholds offered by other nanolaser types while still offering electromagnetic isolation, telecom-band operation and current injection. In this dissertation, we mainly focus on exploring additional attributes of MDNLs that further lend credence to their suitability for dense integration on-chip. One of these desirable traits we study includes reversible wavelength tuning (upto 8.35 nm) and intensity modulation of an MDNL based on an external electric field (Chapter 2). More importantly, we report that this electric-field based intensity modulation can be performed at high-speeds of upto 400 MHz (limited only by the detector bandwidth). A second characteristic appropriate for dense integration involves investigating the presence of coupling when two MDNLs are designed in proximity on-chip (Chapter 3). Our results indicate that not only does coupling occur, but it can also be inhibited if independent operation of the emitters is required. We further explore the concept of coupling but with regards to phase-locking two high-b, laterally coupled lasers (Chapter 4). We found that high b values, that are usually only exhibited in nanolasers such as MDNLs, help significantly increase the stable phase-locking regions for two coupled lasers. Additionally, high b can also lead to a wider range of phase differences attainable for a stable nanolaser system (p) compared to what has been demonstrated for commercially available semiconductor lasers (p/10). Finally, we review some unique applications that have already been made possible by the inevitable next step in the nanolaser technology of integrating into dense arrays (Chapter 5) and we briefly discuss a couple of future directions that are worth pursuing in the nanolaser-arrays research field (Chapter 6).