Influence of Photonic Crystal Size and Lattice Constant on the Lasing Perfomance of UV-C PCSELs
D. Apaydin1, L. Persson1, M. Riedel2, S. Graupeter3, J. Ciers1, T. Wernicke3, M. Kneissl3,4, U.T. Schwarz2, and A. Haglund1
Published in:
ACS Photonics, vol. 13, no. 20, pp. 6199, doi:10.1021/acsphotonics.6c01610 (2026).
Abstract:
Semiconductor lasers are compact, high-power coherent light sources across a broad wavelength range in theelectromagnetic spectrum, including visible and infrared. Despite significant progress, they have yet to achieve the same performancefor ultraviolet-C (UV-C) wavelengths (?0 < 280 nm). Photonic crystal surface-emitting lasers (PCSELs) are a special type ofsemiconductor lasers and have shown high single-mode output powers and low-divergent beams for the infrared and visiblespectral range. So far, UV-C PCSELs have only been demonstrated under optical pumping. Here, we investigate the influence of designparameters, such as the photonic crystal size and the lattice constant, on the lasing characteristics in optically pumped UV-CPCSELs through experiments and simulations. We show that the PCSELs are very sensitive to the lattice constant, where a rangefrom 137 to 140 nm results in low-threshold devices. Also, the PCSEL size influences the threshold, which increases drastically forPCSELs < 70 µm. Finally, we explain the origin of high-angle lasing modes and how they can be suppressed by a small PCSEL size.For a device size around 70-90 µm in diameter, both a low-divergence far-field emission and a relatively low threshold can beachieved. Our findings provide a deeper understanding of UV-C PCSELs and pave the way for the development of future electricallydriven high-power light sources
1 Chalmers University of Technology, Department of Microtechnology and Nanoscience, 41296 Gothenburg, Sweden
2 Chemnitz University of Technology, Institute of Physics, 09126 Chemnitz, Germany
3 Technische Universität Berlin, Institute for Physics and Astronomy, 10623 Berlin, Germany
4 Ferdinand-Braun-Institut (FBH), 12489 Berlin, Germany
Keywords:
photonic crystal, UV-C, UVC, PCSEL, semiconductor, semiconductor lasers, semiconductor laser, Lasers, Laser, high-power, high power, Light sources, visible, surface-emitting laser, Surface emitting lasers, single-mode, single mode, output power, Optical pumping, Simulations, Simulation, low divergence, far-field, far field
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