Optics and Photonics Society of Iran

In this paper design and fabrication of an 8-12 micron antireflection coating on zinc sulfide substrate with good environmental durability is reported. This five layer is coated by e-gun, heating boat and PECVD methods using a quartz crystal to measuring the thickness. The chamber pressure order during the process was 10^-6mbar. In this coat, diamond like carbon is used as top protection layer in order to increase the mechanical hardness and environmental stability. This five layer passed the environmental tests and the abrasion test in agreement with related standards. The optical reflection of this coat in 8-12 micron wavelenght range, was less than 1.5%.