Research on the measurement method for a large laser beam profile based on CCD diffuse transmission imaging

Abstract

The intensity distribution of a laser beam (laser beam profile) is one of its most important characteristics because it yields information on the non-uniformity, centroid, centroid jitter and beam quality. A novel measurement method for obtaining a large laser beam intensity distribution based on CCD diffuse transmission imaging is proposed. The measurement principle is presented. The measurement components of the system have been designed. The layout of the system and the design of a diffuse transmission sampling target are emphasized. The methods of correcting geometric and intensity distortion of the spot are described in detail. The method to calibrate the power coefficient is also given. After the laser spot correction, we can obtain the precise laser beam intensity profile as well as the laser power. The presented test results validate the method. In the measurement field of large laser beams, the method can measure the profile with a non-uniformity of less than 1%, and laser power within 2% error compared with the calibration power meter. The measurement system can be used as a standard measurement instrument after being calibrated when manufactured.

LED diffused transmission freeform surface design for uniform illumination

“…Ripoll J proposed the expression of the reflection and transmission coefficients at the diffusiondiffusion interface [16]. M. Pang proposed a novel measurement method for obtaining a large laser beam intensity distribution based on CCD diffuse transmission imaging [17]. Serra et al [18] investigate the CW transmitted light profiles when an inhomogeneity is immersed in highly scattering media slabs.…”