Lecture Giuseppe Visimberga
|26 October 2009||FWN-Building 5114.0004, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Dr. Giuseppe Visimberga|
|Affiliation:||Tyndall National Institute of UCC, Cork, Ireland|
|Title:||Aluminum coating of Zinc Oxide nanowire lasers: modified optical and structural properties inducing enhanced lasing|
|Date:||Mon Oct 26, 2009|
|Telephone:||+31 50 363 4119|
Zinc Oxide nanowires are promising building blocks for novel miniaturized optical and optoelectronic devices because of their remarkable properties in terms of wave guiding and UV lasing. Whereas high structural purity is a prerequisite for efficient laser emission, metal coating of the end facets is expected to enhance their laser performances in terms of a reduced excitation power threshold. This can be achieved with a simple technological step, namely electron beam sputtering of an Aluminium thin layer.
The experimental investigation of single free-standing Al-coated ZnO nanowire lasers shows that, along with the formation of a high-reflectance mirror facet at one end, the Aluminium coating induces further optical cavity modifications in ZnO nanowires leading to low-threshold lasing. These include the suppression of surface state losses and the enhancement of the laser spectral purity through the reduction of both the number and the modal gain of higher order guided modes.
|Last modified:||22 October 2012 2.30 p.m.|