Latest Developments on Membrane External-Cavity Surface-Emitting Lasers (MECSELs)

Membrane external-cavity surface-emitting lasers (MECSELs) are a new kind of vertically emitting semiconductor laser with enormous potential and versatility for tailoring the laser parameters. Part of their benefits is related to the fact that they do not employ integrated distributed Bragg reflectors (DBRs), which are known to hamper the heat transfer and limit wavelength versatility via strain and band-gap engineering constrains. Furthermore, the substrate on which the active region is grown on is removed and the resulting thin active region membrane is sandwiched between transparent intra cavity heat spreaders for improved thermal management. Based on the membrane geometry of MECSELs, an intrinsically excellent beam quality is another benefit of this new vertically emitting laser kind. MECSELs have experienced a rapid progress in recent years. The latest developments will be discussed and an overview of future perspectives will be given. The most important recent progress, like continuous wave broadband tuning and anti-resonant gain membrane design play a major role. MECSELs with all their benefits are bringing new dynamics in the field of vertical semiconductor emitters.

Subject Matter Level: Intermediate - Assumes basic knowledge of the topic

What You Will Learn:
• Key aspects of the vertical emitting semiconductor laser technology, especially VECSELs and MECSELs
• Recent progress in the development of high-performance MECSELs

Who Should Attend:
• Graduate students and early-career researchers to senior academics
• Everyone interested in laser R&D, especially semiconductor and surface emitting technologies
• Industry representatives

About the Presenter: Hermann Kahle from Institute of Nanostructure Technologies and Analytics, University of Kassel

Hermann Kahle received his PhD in Physics at the University of Stuttgart, Germany in 2016, on the detailed investigation and optimization of red emitting semiconductor disk laser structures. He developed a novel concept - the membrane external-cavity surface-emitting laser with the first double-side diamond cooling implementation. After PhD graduation he moved to Tampere, Finland, where he joined the Optoelectronics Research Centre (ORC) at the Tampere University in 2017. He was leading a research team further investigating this novel category of heat spreader sandwiched membrane structures as laser gain elements. After a short research stay in 2022 at Kassel University, Germany, he joined the Institute for Photonic Quantum Systems (PhoQS) at Paderborn University in 2023. In 2024 he moved to the US and joined The University of New Mexico at the Department for Physics and Astronomy continuing research on MECSELs in the NIR spectral range and for high-power applications.