Optical effects of gas flow through an optical train: an experimental determination

High power laser optical systems often require gas flow in the optical train to control effects such as thermal blooming. The gas flow is itself a source of optical degradation for the laser beam. An experimental investigation has been performed for a scale simulation of a typical optical train. Optical effects of the type of gas used and the method of flow injection have been ascertained. It was determined that substantial optical degradation can be caused by the flow, and a number of qualitatively desirable flow implementations, which produced little degradation, were identified.