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Updated: Oct 25, 2026

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
Homotopic Vortex Lasing Mediated by a Resonant Geometric Phase in a Bound States in the Continuum Cavity
Ronghui Lin1, Thi Thu Ha Do1, Emek Goksu Durmusoglu2
1Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way, Innovis #08-03, Singapore138634, Republic of Singapore.
Abstract:
Geometric phases are fundamental to wave physics and underpin a broad range of optical phenomena. The most prominent example, the Pancharatnam-Berry (PB) phase, originates from polarization evolution during wave propagation. In contrast, geometric phases associated with optical resonances and cavities remain largely unexplored. Here, we uncover the relation between the generalized PB phase and the far-field polarization evolution in bound states in the continuum (BIC) cavities. We demonstrate the continuous homotopic evolution of vortex lasing modes through geometric-phase engineering of BIC resonances. To experimentally validate this concept, we realize metasurface lasers composed of titanium dioxide hole arrays integrated with CdSe/CdxZn1-xS core/shell colloidal quantum wells as the gain medium. Our results reveal a previously unexplored form of spin-orbit interaction in BIC cavities under oblique incidence and provide a versatile route for on-chip control of polarization and orbital angular momentum in nanolasers.
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