Theoretical Study of the Optical Specifications of some Materials Used as Resonator for Nd- (YAG Laser (1064 nm

Abstract

In this research, the Macleod software which meet the requirements of the most sophisticated designer and the fastest solution of various i design problems was used to design and analyze the optical specifications of multilayered (thin films ) that can be used as resonator for Nd-YAG Laser (1064 nm). The different film optical filters were used to control the transmittance and reflectance. Different samples of dielectric materials composed of HgS / Na3AlF6, HgS / MgF2, CdS/ Na3AlF6, CdS/ MgF2, ZnS/MgF2 and ZnS/Na3AlF6 and oxide materials of ZnO/ Na3AlF6, ZnO/ MgF2, HfO2/ Y2O3, TiO2 / Y2O3, SiO2 / Y2O3, Sc2O3 / MgO, Al2O3 /SiO2,T iO2 /SiO2,Ta2O5/SiO2, ZrO2/SiO2 and Ta2O5 /TiO2 were used and compared with each other in transmittance, reflectance, physical thickness, optical thickness, geometric thickness, full width at half maximum ( FWHM ) and incidence angle by the Macleod software. It was found that the dielectric material ZnS+ Na3AlF6 with 2007.47 nm physical thickness and 2.50000/1.38030 refractive index at range of 875- 1000 nm was the best in transmittances, reflectance, physical thickness, optical thickness, geometric thickness, full width at half maximum (FWHM) and incidence angle compared to other materials so it is suitable as an output coupler with high transmittance of 95.74% for Also the Nd :YAG ( 1064 nm ) Laser. dielectric materials (Ta2O5 / TiO2 ) with 8697.78 nm physical thickness and 2.10000/2.2500 refractive index at wavelength range of 800 -2000 nm was the best ii in all characteristics for transmittances, reflectance, physical thicknesses, optical thickness, geometric thickness, full width at half maximum (FWHM) and incidence angle compared with other materials. So it is suitable as a back mirror with high reflectance of 98.91 % for Nd:YAG (1094 nm) Laser. For more improvement, Ta2O5/TiO2 glass substrate was replaced by Ag substrate. It was found that with Ag substrate the change in reflectivity (%) was very simple with the change in the incidence angles. Also the number of layers and the thickness of the sample were less than the glass substrate . Therefore, Ag substrate was much better than the glass substrate and is recommended for use in Laser mirrors. Thus the major obstacle for improving the output of high- power Nd:YAG laser systems is resolved. Among the chosen materials, one can conclude that a resonator can be fabricated from Ta2O3/TiO2 with 66 Layers as back mirror and of ZnS+ Na3AlF6 with 13 layers as anoutput coupler