Descrizione del progetto
Innovazione del laser a microcavità per la luce ultravioletta
Il progetto UV-LASE, finanziato dall’UE, mira a produrre il primo laser a microcavità in grado di generare luce ultravioletta che potrebbe essere applicato al mondo reale. Grazie al rivoluzionario lavoro del progetto, le elevate perdite ottiche e la densità dei difetti non ostacoleranno più l’attuazione di questo tipo di laser. L’approccio del progetto si basa su un’esclusiva tecnica a membrana che consente l’utilizzo di laser a cavità verticali con specchi dielettrici altamente riflettenti su entrambi i lati della cavità, un concetto di dispositivo precedentemente impossibile da realizzare per i laser ultravioletti. Il progetto proposto comporterà anche un aumento di dieci volte della potenza di uscita ottica, in quanto consente di evitare la non linearità, un meccanismo di perdita trascurato nelle microcavità.
Obiettivo
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.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-COG - Consolidator GrantIstituzione ospitante
412 96 GOTEBORG
Svezia