Instruments and standard measurement procedures for laser beam characterization

Abstract

The EUREKA-project CHOCLAB (Characterization of Optical Components and Laser Beams), which was initiated in 1995, aims to investigate and develop instruments and standard measurement procedures for laser beam and laser optics characterization. From the start of the project, one of the main work items in the field of laser beam characterization has been the determination of the beam propagation parameters (beam width, divergence angle and beam propagation factor). The most common measurement devices for these purposes are 2d-matrix-cameras (i.e. CCD-cameras), 1d or 2d scanning devices (i.e. scanning pinholes and/or moving knife- edges)--both of them requiring further evaluation of the measured power density distribution to obtain laser beam parameters--and variable transmission/reflectivity optical elements, which allow the direct measurement of beam properties. The advantages and drawbacks of the different types of measurement devices, as well as measures to reduce systematical and statistical errors will be discussed.