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Shaping the light of VCSELs through cavity geometry design
Hang Lu1, Omar Alkhazragi1,2, Heming Lin1
1Photonics Laboratory, Electrical and Computer Engineering Program, Division of Computer, Electrical, and Mathematical Sciences and Engineering (CEMSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia.
Light, Science & Applications
|September 28, 2025
Summary
Cavity geometry significantly impacts vertical-cavity surface-emitting lasers (VCSELs). Non-circular shapes, like pentagonal, boost optical power and mode dynamics, offering tailored performance for advanced photonic applications.
Area of Science:
- Optoelectronics and Photonics
- Semiconductor Lasers
Background:
- Vertical-cavity surface-emitting lasers (VCSELs) are crucial for optical communications, 3D sensing, and LiDAR.
- Optimizing VCSEL performance through cavity geometry is an underexplored area.
Purpose of the Study:
- To systematically investigate the influence of various cavity geometries on broad-area VCSEL static and dynamic properties.
- To analyze how circular, square, D-shaped, mushroom-shaped, and pentagonal cavities affect optical power, multimode behavior, beam profile, spatial coherence, and polarization dynamics.
Main Methods:
- Experimental and theoretical analysis of VCSELs with distinct cavity geometries.
- Evaluation of optical power density, mode characteristics, beam profiles, spatial coherence, and polarization dynamics.
Main Results:
- Breaking rotational symmetry enhances gain utilization, optical power, and modifies lasing characteristics and polarization.
- Pentagonal VCSELs show >2x power density and fastest mode dynamics; mushroom-shaped VCSELs offer high power with low spatial coherence; D-shaped VCSELs provide stable polarization and controllable multimode behavior.
- Cavity geometry dictates VCSEL performance, enabling tailored designs for specific applications.
Conclusions:
- Cavity geometry is a critical design parameter for optimizing VCSEL performance.
- Specific geometries (pentagonal, mushroom, D-shaped) offer unique advantages for applications ranging from high-speed communication to speckle-free imaging and stable low-coherence sources.
- This research provides foundational insights for developing next-generation VCSELs for diverse photonic technologies.
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