26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Telecom-Wavelength III-V Metasurface Laser via Brillouin-Zone-Folded Guided-Mode Resonance

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral ANZOS | Photonics and Optics (ANZCOP)

Speaker

Mr Joshua Jordaan (Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2600, Australia)

Description

Surface-emitting semiconductor lasers provide a highly adaptable, compact and integrable light source for a range of rapidly growing applications, spanning consumer devices, data-centre interconnects, 3D sensing, and the automotive and robotics industries. Vertical-cavity surface-emitting lasers (VCSELs) are the most mature devices in this category, achieving surface emission through single-mode cavity dimensions and distributed reflectors. However, their small emission apertures typically produce large divergence angles exceeding 20°. As an emerging alternative, photonic-crystal surface-emitting lasers (PCSELs) exploit band-edge modes with selective in-plane feedback to achieve vertically emitting, single-mode lasing over large cavity volumes, with far-field divergence angles below 0.3°. These devices, however, generally require complex cavity architectures both to ensure adequate coupling between the structured photonic crystal and the active region and to maintain single-mode operation at the large aperture sizes needed for low divergence.

Recent advances in metasurface optics have enabled alternative surface-emitting laser concepts based on periodic subwavelength resonators. Brillouin-zone folding grants access to high-Q guided resonances by folding otherwise non-radiative slab modes into the radiation continuum, enabling single-mode surface emission in planar structures without conventional vertical cavities or otherwise complex cavity designs.

Here for the first time, we demonstrate a Brillouin zone-folded guided-mode resonance semiconductor metasurface laser operating within the Telcom C-band. We experimentally verify ultra-low femtosecond-pumped threshold and Γ-point surface-normal emission with beam divergence below 5°. The device utilizes a directly patterned InP/InGaAs multi-quantum-well metasurface transferred onto sapphire. This configuration allows for convenient back-side optical pumping combined with ultra-low threshold, and narrow normal emission while maintaining a highly simplified cavity structure.