Topological lasers

ORAL

Abstract

Recently, we have demonstrated novel lasers which exploit the topological properties of the photonic band structure to control the scaling and emission profile of semiconductor lasers. Among them are topological lasers based on the quantum-hall and valley-hall effects. These laser cavities rely on feedback from edge-modes that are robust to disorders and can produce vortex beams with orbital angular momentum. We also developed the first bound state in the continuum (BIC) laser which can minimize the threshold for small cavities and investigated their viability for electrical injection. Due to the properties of this topological singularity, lasers operating at BIC modes can be optimized for both small and large scale apertures. In this talk, we will focus on the scaling of photonic crystal lasers with increasing cavity size. The influence of the symmetry of the modes and the coupling between Bloch bands on the lasing response will also be discussed. Finally, we conclude by introducing a scheme that can improve the threshold gain difference between the fundamental and higher-order modes and enable single-mode lasing in large-scale photonic crystal lasers.

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Publication: Bahari, B. et al. Nonreciprocal lasing in topological cavities of arbitrary geometries. Science 358, 636–640 (2017).
Noh, W. et al. Experimental demonstration of single-mode topological valley-Hall lasing at telecommunication wavelength controlled by the degree of asymmetry. Opt. Lett., OL 45, 4108–4111 (2020).
Bahari, B. et al. Photonic quantum Hall effect and multiplexed light sources of large orbital angular momenta. Nat. Phys. 17, 700–703 (2021).
Kodigala, A. et al. Lasing action from photonic bound states in continuum. Nature 541, 196–199 (2017).
Contractor, R., Noh, W., Le-Van, Q. & Kanté, B. Doping-induced plateau of strong electromagnetic confinement in the momentum space. Opt. Lett. 45, 3653 (2020).

Presenters

  • Rushin Contractor

    University of California Berkeley

Authors

  • Rushin Contractor

    University of California Berkeley

  • Walid Redjem

    University of California Berkeley, UC Berkeley

  • Wanwoo Noh

    University of California Berkeley

  • Hwi Min Kim

    University of California Berkeley

  • Boubacar Kante

    University of California Berkeley, UC Berkeley, University of California, Berkeley