New types of microlasers with improved performance and unique functionalities have always been pursued to open up new opportunities to discover novel physical phenomena and generate new application potential. In this project, we aim to design and fabricate rolled-up perovskite microtube cavities to explore three-dimensional (3D) lasing. The 3D active microtube cavity provides a higher degree of freedom for manipulating the laser resonances, suggesting a versatile platform to explore novel physical effects and applications based on 3D microlasers. Metal halide perovskites are selected as the optical gain medium for the fabrication of microtube lasers owing to their large optical gain coefficient and chemically tailorable bandgap. The integration of optical gain media into specially designed microtube cavities is expected to demonstrate new laser device concepts for multiple orthogonally polarized emission beams, 3D directional lasing and on-chip multichannel lasing. With this investigation, we would pave the way for perovskite microtube lasers that can simultaneously deliver coherent light for different photonic components distributed in 3D space. The multichannel lasing source could become a key element in wavelength division multiplexing for on-chip parallel communication and optical data processing.

The purpose of this project is to investigate topological state transition in Su-Schrieffer-Heeger (SSH) waveguide arrays enabled by manipulating optical phase differences in neighbouring waveguides. For topological phase tuning, the complexity of previously reported modulation methods is one of the main impediments to the development of topological photonic devices for practical applications. This project will investigate topological state transition by tuning optical phase in topological SSH waveguide arrays which support asymmetric topological edge states (a-TES). By changing the optical phase difference in neighbouring waveguides, topological state transition can be realized, which provides a simple and efficient way for TES manipulation. Numerical simulations will be carried out to predict the underlying basic principles and support the design of the proposed photonic lattice.

Here we aim to investigate the spin-orbit coupling in Möbius-strips, where right/left handed circular polarization basis provides spin angular momentum while the rotation of optical electric field along the twisted strip provides orbital angular momentum. In theoretical studies, both analytical model and numerical simulation will be explored to illustrate and predict the underlying fundamental principles and support the design of the Möbius-strip. In experimental investigation, optical scan mapping will be used to reveal the mode distribution. In addition, by manipulating the number of twists as well as the geometry of the strip, the manipulation of spin-orbit coupling will be investigated.