1. University of Arkansas, Microelectronics-Photonics Program, 731 West Dickson Street, Fayetteville, Arkansas 72701, United States
2. University of Arkansas, Department of Physics, 825 West Dickson Street, PHYS 226, Fayetteville, Arkansas 72701, United States
3. University of Arkansas, Microelectronics-Photonics Program, 731 West Dickson Street, Fayetteville, Arkansas 72701, United StatesbUniversity of Arkansas, Department of Physics, 825 West Dickson Street, PHYS 226, Fayetteville, Arkansas 72701, United States