“…One attractive method of developing such a source is through frequency doubling of CO 2 laser emission by establishing the condition of phase matching in nonlinear crystals, e.g. AgGaSe 2 [1], GaSe [2], ZnGeP 2 [3], CdGeAs 2 [4], LiGaTe 2 [5] and LiInSe 2 [6]. In addition, the search for new and more appropriate crystals continues to be an area of interest [7,8].…”