A new design method for a refractive beam shaping optical system operating in mid-infrared band

Jamming code development set-ups are generally employed for evaluating the jamming code effectiveness of Directed Infrared Countermeasure (DIRCM) Systems on seeker heads in laboratory conditions. In these set-ups, usually, the output beam of a mid- infrared (mid-IR) laser having similar properties with the DIRCM laser is expanded and collimated before directing it to the seeker head so that a beam with an almost-homogeneous intensity distribution is obtained at the seeker aperture. This simulates what would be expected in a real long distance engagement scenario where an infrared heat seeking missile is attacked by a countermeasure laser and the laser beam diverges to create an almost-homogenous intensity profile at the seeker aperture provided that the effect of atmospheric turbulence is neglected. Large aperture off-axis parabolic mirrors are often employed for the purpose of expanding and collimating the laser beam in these set-ups. However, instead, it is also possible to employ refractive beam shaping optical systems that are much smaller in size compared to these large collimating mirrors in an effort to reduce the laser power loss, required space, and cost for obtaining such uniform laser beam profiles.