Measurement and Evaluation of Absorption Coefficient of Some Materials for Lasers in Infra Red Region

Abstract

In this study 3 types of materials selected: lead sulfate (PbSO4),zinc sulfide (ZnS), mixture of lead sulfate (PbSo 4) and zinc sulfide (ZnS) and antimony trioxide (Sb 2O3),which undergoes spectroscopical analysis using FT-IR spectrometer before and after irradiation by different wavelengths (810, 820, 1064) nm in IR region. Selected materials divided into four groups, five discs (D=1.4cm) were manufactured from each group by using pressing machine. Incident intensity (I 0) and transmitted intensity (I) through materials measured using three laser sources (diode laser �=810nm P=100mW, diode laser �=820nm P=200mW and Nd: YAG laser �=1064nm P=10W),Laser sources used to irradiate the materials then incident intensity (I 0) and transmitted intensity detected by photoelement and then readout using digital multimeter.The relation between the ratio of transmitted to incident intensity (I/I 0) and thickens has been plotted and absorption coefficient determined. The results showed that lead sulfate (PbSO 4) has absorption coefficients (0.01258, 0.05352, 0.03617) cm-1 for wavelengths (810, 820, 1064) nm respectively. (PbSO4) can be used to fabricate filter at wavelengths (810, 1064) nm with high efficiency. Zinc sulfide (ZnS) has absorption coefficients (0.05624, 0.04155, 0.07421) cm-1 for wavelengths (810, 820, 1064) nm respectively. (ZnS) can be used to fabricate attenuator at wavelength (1064) nm with high efficiency, also can be used to fabricate filter at wavelength (820) nm, with moderate efficiency. Mixture of lead sulfate (PbSo 4) and Zinc sulfide (ZnS) has absorption coefficients (0.05331, 0.03874, 0.0847) cm-1 for wavelengths (810, 820, 1064) nm respectively. This material can be used to fabricate attenuator at wavelength (1064) nm with high efficiency; also can be used to fabricate filter at wavelength (820) nm with moderate efficiency. The antimony trioxide (Sb2O3) (0.03495, 0.05905, 0.04496) has absorption coefficients cm-1 for wavelengths (810, 820, 1064) nm respectively. (Sb2O3) can be used to fabricate filter at wavelength (810) nm with high efficiency.