Obliquity factor for radiation from solid-state laser

The radiated field consists of forward radiation at an angle θ and backward radiation at π – θ reflected from the dielectric-air interface into an additional component of field at angle θ. The total radiation contains a factor that simplifies into an expression recently obtained by more sophisticated methods, and which is here interpreted as the Huygens obliquity factor for the arrangement. A small correction to the expression is also obtained.