Development of highly damage resistant anti-reflection coating

摘要

High power laser is an important tool for industry. MITSUBISHI CABLE INDUSTRIES, LTD. is supplying optical glass fibers for high power lasers. It is very important to supply for the edge face of the optical glass fiber with antireflection coating (AR) to reduce reflection loss. However, there is not AR coating for high power laser, further the AR coating is of no practical use. We have developed a highly resistant AR coating for high power YAG laser of more than 4 kW. In this paper, we studied an AR with a high damage resistance by Taguchi method and laser annealing. This AR coating has a reflectance of for ≤0.2% at 1064 nm (Nd:YAG laser) and a damage threshold of 14.7 J/cm{sup}2 at 1064 nm (τ = 7 ns). It is possible for the AR coating to use YAG laser guide of the 10 kW class.