A real-time visual display of a high-power laser-beam

A technique is described whereby the focused output of a high power laser, such as the CO₂, can be quickly and effectively characterised. Precisely machined pinholes and special high power detectors are not required; a scanning beam is employed in conjunction with simple electronic circuitry. The novelty of the system is in the method of attenuation, which is very flexible, so that a beam of virtually any high power-density can be safely and easily measured. Very high resolution is available since extremely small portions of the beam can be sampled.