Tunable mid infrared radiation in the range 2.6 to 5.2 mu m is generated in
a flux grown KTiOAsO4 crystal by noncollinear difference frequency mixing
of Nd:YAG second harmonic and the same pumped dye laser radiations as input
fundamental radiation sources and with the generated infrared source the i
nfrared absorption spectra of polythene sheets have been studied.