1. Department of Physics, University of Isfahan, 81747-73441 Isfahan, Iran
2. Quantum Optics Group, Department of Physics, University of Isfahan, 81747-73441 Isfahan, Iran
3. Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
4. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States