Intracavity Adaptive Optics

A major consideration in most laser resonator designs for high power is to obtain the maximum far field irradiance on a target. Various design approaches have emerged in recent years to optimize the far-field irradiance by utilizing different resonator concepts for the purpose of obtaining the best mode control and near field beam quality. The different concepts utilize annular and compacted gain mediums, spatial filtering techniques, novel optical components and adaptive optics. This paper will describe recent results using intracavity adaptive optical techniques versus extracavity adaptive optical techniques. Experimental results will be provided which will show the correction capability for low order aberrations (tilt and astigmatism) commonly found in high energy lasers. A comparison of several optimization control techniques using a multidither zonal COAT system will be discussed describing the effects of hardware limitations and considerations on the performance of the system.