High orbital angular momentum lasing with tunable degree of chirality in a symmetry-broken microcavity

• Main Authors: Qiao, Zhen, Yuan, Zhiyi, Zhu, Song, Gong, Chaoyang, Liao, Yikai, Gong, Xuerui, Kim, Munho, Zhang, Dawei, Chen, Yu-Cheng
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering; Orbital Angular Momentum; Integrated Photonic Devices
• Online Access: https://hdl.handle.net/10356/171065
• Institution: Nanyang Technological University

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 strategy to generate OAM microlasers with tunable DOCs 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 OAM with tunable quantum numbers were also demonstrated, in which the largest quantum number reached up to 352. Finally, multivortex 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 insights for high-dimensional information processing and optical communications.