Laser intensity distribution measuring method based on fiber array

A method for measuring laser intensity distribution based on fiber array is presented. The principle and structural design of the fiber array are introduced. The attenuation characteristic is analyzed theoretically. A demonstration module is built in our lab. And experiments are carried out with a high power fiber laser operating at 1064 nm. The experimental results show that this system can provide laser power density distribution information with a spatial resolution better than 3 mm and with a measurement error less than 3%. Experiments with fiber laser radiation and numerical simulation by the finite element method indicate that the damage threshold of the fiber array is higher than 10 kW/cm2 with a radiation time of 50 s. Therefore, it might be appropriate for the method to measure the high energy laser beam directly.