1. Applied Optics Laboratory, School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
2. Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
3. Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
4. Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
5. Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA