Design of measurement equipment for high power laser beam shapes

To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD-chip implemented in a camera system. Most available CCD-based systems do however suffer from a low maximum intensity threshold. Therefore attenuation is needed. This paper describes the construction of such a beam analysing system where beam
patterns produced by single mode fiber laser on a diffractic optical element can be evaluated using a CCD based camera. The system is tested with various DOE’s for evaluation of efficiency and measurement of scattered light with success. Also tests with capturing beam caustics of focused laser beams from which beam parameters has been fitted and compared with measurements by a
commercial product has been done. The realised system might suffer from some thermal drift at high power; future work is to clarify this.