1. Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
2. Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
3. Engineering Research Center of Industrial Computed Tomography Nondestructive Testing, Ministry of Education, Chongqing University, Chongqing 400044, China