Advanced Methods of Semiconductor Research Seminar – Tuesday 7th of October 2025
We cordially invite you to Advanced Methods of Semiconductor Research Seminar on Tuesday 7th of October 2025 at 13:15 in room 321, building A-1, where there will be delivered a lecture:
Coherence-Controlled VCSEL: from Design to Application
by Wenbo Yan
from King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
The lecture abstract is attached below.
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Lecture abstract:
Vertical-cavity surface-emitting lasers (VCSELs) are a class of semiconductor lasers that emit light perpendicular to the wafer surface, in contrast to edge-emitting lasers (EELs), which emit light from cleaved facets. VCSELs offer significant advantages, including ease of fabrication, wafer-level testing, and low-cost mass production. As a result, they are widely deployed in applications such as optical communication, computer mice, laser printing, facial recognition, and emerging wearable technologies like smart glasses.
A central topic in laser research is coherence control. High spatial coherence enables highly directional beams with low divergence and diffraction-limited focusing. However, it also introduces unwanted effects such as coherent artefacts and crosstalk in imaging, displays, and advanced applications including materials processing, photolithography, holography, and optical trapping.
In this seminar, I will present our recent efforts on engineering the coherence of VCSELs through cavity geometry design. I will also highlight potential applications explored in our lab, including wireless optical communication, physical unclonable functions, and random number generation.
