Buried Subwavelength Gratings for Polarization Pinning of Bottom-Emitting GaAs VCSELs
Journal article, 2026
We demonstrate bottom-emitting GaAs vertical-cavity surface-emitting lasers (VCSELs) incorporating a buried subwavelength grating in the top, highly reflective distributed Bragg reflector (DBR), with oxide aperture diameters ranging from 2 to 6. The buried grating successfully pins the polarization for aperture diameters up to 4 mu m, and the 3 mu m aperture VCSELs achieve single-mode, single-polarization operation, delivering 3.9 mW of output power with a side-mode suppression ratio exceeding 30 dB and an orthogonal polarization suppression ratio (OPSR) of 20 dB. Simulations and measurements indicate that the buried surface-etched grating can only weakly influence the lasing mode in the bottom-emitting configuration, thereby preventing polarization pinning of higher-order modes in larger-aperture VCSELs. The surface-etched gratings introduce minor degradation in threshold current, slope efficiency, and beam profile.
Gratings
Etching
Vertical-cavity surface-emitting laser
subwavelength gratings
Apertures
Surfaces
polarization pinning
Pins
Vertical cavity surface emitting lasers
Indexing
PIN photodiodes
Polarization
monolithic integration
Indexes
Author
Erik Strandberg
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Mindaugas Juodenas
Kaunas University of Technology
Alexander Grabowski
Solinide Photonics
Åsa Haglund
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
IEEE Journal of Selected Topics in Quantum Electronics
1077-260X (ISSN) 15584542 (eISSN)
Vol. 32 6 1701408Metasurface-Emitting Lasers: Tomorrows Light Sources for Applied Photonics
Knut and Alice Wallenberg Foundation (2020.0119), 2021-07-01 -- 2026-06-30.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Telecommunications
Other Physics Topics
DOI
10.1109/JSTQE.2026.3714146