Design and fabrication of confocal fabry-perot interferometers used in laser-ultrasonic detection

• DING Hongsheng¹ , 
• TONG Lige² , 
• BAI Shiwu³

• 1. Department of Physics, University of Science and Technology Beijing, Beijing 100083, China;

• 2. Mechanical Engineering School, University of Science and Technology Beijing, Beijing 100083, China;

• 3. Pipeline Research Institute of China National Petroleum Corporation, China