Projektbeschreibung
Durchbruch von Mikrokavitätslasern für ultraviolettes Licht
Das EU-finanzierte Projekt UV-LASE zielt darauf ab, den ersten Mikrokavitätslaser zur Erzeugung von UV-Licht herzustellen, das in der realen Welt angewendet werden könnte. Dank der bahnbrechenden Arbeit des Projekts werden hohe optische Verluste und Defektdichten die Einführung dieses Lasertyps nicht länger behindern. Der Ansatz des Projekts basiert auf einer einzigartigen Membrantechnik, die vertikale Hohlraumlaser mit hochreflektierenden dielektrischen Spiegeln auf beiden Seiten des Hohlraums ermöglicht – ein Gerätekonzept, das für UV-Laser bisher nicht realisierbar war. Das vorgeschlagene Design wird zudem auch die optische Ausgangsleistung um das Zehnfache erhöhen, da es einen Weg zur Umgehung von Antiguiding-Effekten bietet, einen meist übersehenen Verlustmechanismus in Mikrokavitäten.
Ziel
Achieving ultraviolet (UV) emission has proven to be difficult, in particular for microcavity lasers due to high optical losses and defect densities. Our group, with a world-leading position in microcavity laser research, has identified new possibilities to combat these challenges in both ultraviolet and blue-emitting devices. By using these breakthroughs, we aim to develop the first electrically injected blue microcavity laser with good enough performance to be useful in real-world applications and project out of the blue and into the ultraviolet to realize the very first electrically injected UV microcavity laser. Our two recent breakthroughs are:
1. The discovery of an overlooked loss mechanism in microcavities and schemes to circumvent it. Our proposed designs to circumvent this unintentional anti-guiding are being implemented worldwide and have led to a tenfold increase in optical output power in blue lasers.
2. A unique membrane technique to enable microcavity lasers with highly reflective dielectric mirrors on both sides of the cavity – a device concept previously un-realizable for UV-lasers. The method is based upon electrochemical etching of the chemically inert material AlGaN (the material of choice for UV), which enables lift-off of device membranes with smooth surfaces from the substrate and mirror-deposition on the bottom side. Our recent demonstration of the world’s first thin-film, flip-chip UV-B LED with this technique holds great promises for microcavity lasers.
These two new approaches will be combined with a focused effort to circumvent the problem of low electrical conductivity of p-doped materials. We will strengthen our capabilities by developing tunnel junctions, allowing highly conductive n-doped material to be used throughout virtually the entire laser. This will drastically reduce losses, which cause degradation within minutes in blue microcavity lasers, and might be the only solution to electrically driven UV microcavity lasers.
Wissenschaftliches Gebiet
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-COG - Consolidator GrantGastgebende Einrichtung
412 96 GOTEBORG
Schweden