1. Department of Electrical Engineering, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
2. Centre for Advanced Materials & Related Technologies (CAMTEC), University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
3. Advanced Optics and Photonics Laboratory, Department of Engineering, School of Science & Technology, Nottingham Trent University, Nottingham NG11 8NS, U.K.