Project description
Microcavity laser breakthrough for ultraviolet light
The EU-funded UV-LASE project aims to produce the first microcavity laser capable of generating ultraviolet light that could be applied to the real world. Thanks to the project's groundbreaking work, high optical losses and defect densities will no longer hinder implementation of this type of laser. The project approach is based on a unique membrane technique that enables vertical cavity lasers with highly reflective dielectric mirrors on both sides of the cavity – a device concept previously impossible to realise for ultraviolet lasers. The proposed design will also result in a tenfold increase in the optical output power, as it provides a route around anti-guiding, an overlooked loss mechanism in microcavities.
Objective
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.
Fields of science
Programme(s)
Funding Scheme
ERC-COG - Consolidator GrantHost institution
412 96 GOTEBORG
Sweden