DLC/BP ultra durable LWIR protective coatings for ZnS windows

DLC/BP ultra durable LWIR (long wave infrared) protective coatings have been designed and prepared on ZnS (Zinc Sulphide) windows successfully. Both of BP and DLC coatings are deposited by RF-PECVD (radio frequency enhanced plasma chemical vapor deposition) process, but in different chamber. The transmittance, micro-hardness and durability of DLC/BP coatings have been investigated, which are measured by FTIR spectroscopy, micro-hardness tester and simulative harsh environmental test system. The ZnS window outer face coated with DLC/BP coatings and inner face coated with high efficient antireflection coatings is also fabricated. In the band of 8~11.5μm, the measured maximum transmittance is above 93% and the average transmittance is about 89%. The coated ZnS windows meet with the demands of LWIR electro-optics systems workable in battlefield environment.