1. Department of Physics and Optical Science Center for Optoelectronics and Optical Communications University of North Carolina at Charlotte Charlotte NC 28223‐0001 USA
2. Air Force Research Laboratory Sensor Directorate Wright‐Patterson AFB OH 45433 USA
3. Air Force Research Laboratory Materials and Manufacturing Directorate Wright Patterson AFB OH 45433 USA
4. Centro de Fisica de Materiales (CSIC‐UPV‐EHU) and Donostia International Physics Center (DIPC) E‐20018 Donostia‐San Sebastian Spain
5. Ikerbasque Basque Foundation for Science 48011 Bilbao Spain
6. University of Nizhny Novgorod Nizhny Novgorod 603950 Russia