A simple online large-spot laser power/energy measurement device

In order to eliminate effect of inhomogeneous light spot, light intensity randomness, beam off-axis in the process of online large-spot laser energy measurement，a simple method was introduced. The laser beam was collected with a common diffusive plate and its spot was decreased so that its spatial information was eliminated and only the intensity information was reserved. At the same time, the sampling spots were laid in the region diffusive light could reach so as to eliminate effect of transmission section and polarization state. Furthermore, the distance between sampling spots and the diffusive plate was much greater than beam size to eliminate the effect of insufficiency of the sensor receiving angle. Laser energy was obtained by a photoelectric integrator. Experiment results indicate that the response in the laser detection surface is coincident and partial intensity change and laser divergence have little effect on the measurement result. The above suggested method can eliminate effect of many factors and ensure the measurement accuracy.