1. Institute of Laser Engineering; Beijing University of Technology; Pingleyuan 100 Chaoyang District Beijing 100124 P.R. China
2. Department of Mechanical; Aerospace and Biomedical Engineering; University of Tennessee; Knoxville TN 37996 USA
3. School of Electronic Science and Engineering; Southeast University; Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology; Ministry of Education; Nanjing 210096 China
4. Department of Physics and Astronomy; University of Waterloo; Waterloo ON N2L 3G1 Canada