Distorted Grating Wavefront Sensing in the Midwave Infrared

Kestrel Corporation has extensive experience using distorted grating wavefront sensors (DGWFS) in a number of applications. The DGWFS has previously been demonstrated in the visible range (400–700 nm) by Kestrel and others. An experimental system was built in a laboratory environment to show that the DGWFS could recover wavefront characteristics of a midwave infrared (MWIR) laser. This paper describes the theory of the DGWFS and the experimental procedures implemented to run the system with the MWIR laser. The sensitivity to the type of gratings employed will be addressed. The results of sensitivity, dynamic range and thermal noise measurements will be discussed.