High Orbital Angular Momentum Lasing with Tunable Degree of Chirality in a Symmetry-Broken Microcavity

Chiral lasers with orbital angular momenta (OAM) are building blocks in developing high-dimensional integrated photonic devices. However, it remains demanding to arbitrarily manipulate the precise degree of chirality (DOC) and quantum numbers of OAM in microscale lasers. This study reports a new strategy to generate OAM microlasers with tunable DOC and large quantum numbers through a ring-structured Fabry-Perot microcavity with nanoscale symmetry-broken geometry. By exploiting the uneven potential of photons distributed in a microcavity, the dissymmetry factor of OAM laser can be continuously tuned from -1 to +1 by manipulating optical pump positions. High-order vortices with tunable quantum numbers were achieved, in which the largest quantum number reached up to 352. Finally, multi-vortex laser generation on chip in spatial and temporal domains was accomplished. This study reveals the fundamental physics of symmetry-broken cavity and provides a simple yet scalable approach for manipulating the chirality of OAM microlasers, offering new insights for high-dimensional information processing and optical communications