High reflectivity III-nitride UV-C distributed Bragg reflectors for vertical cavity emitting lasers
Abstract
UV-C distributed Bragg reflectors (DBRs) for vertical cavity surface emitting laser applications and polariton lasers are presented. The structural integrity of up to 25 layer pairs of AlN/Al0.65Ga0.35N DBRs is maintained by balancing the tensile and compressive strain present between the single layers of the multilayer stack grown on top of an Al0.85Ga0.35N template. By comparing the structural and optical properties for DBRs grown on low dislocation density AlN and AlGaN templates, the criteria for plastic relaxation by cracking thick nitride Bragg reflectors are deduced. The critical thickness is found to be limited mainly by the accumulated strain energy during the DBR growth and is only negligibly affected by the dislocations. A reflectance of 97.7% at 273 nm is demonstrated. The demonstrated optical quality and an ability to tune the resonance wavelength of our resonators and microcavity structures open new opportunities for UV-C vertical emitters.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 05, 2016
- Source ID
- 10.1063/1.4963831
Entities
People
- A. Franke
- Felix Kaess
- J. Tweedie
- M. Bobea
- M. Gerhold
- M. P. Hoffmann
- Ramón Collazo
- Ronny Kirste
- Zlatko Sitar
Organizations
- Army Research Office
- North Carolina State University
- United States Army Research Laboratory