Inline contaminants detection with optical microfiber in high-power laser system

Abstract

The rudimental microparticle contaminants and airborne molecular contaminants (AMCs) will obviously reduce the lifetime of the lens widely used in the high peak power laser system. An inline contaminants sensor based on the optical microfiber (OM) is here proposed. Due to Van Der Waals force and electrostatic attraction, contaminants are easily adhered to the surface of OM, which will cause an obvious perturbation to the evanescent field transmitted in the OM. The additional loss, caused by the adhered contaminants, has been theoretically analyzed and simulated. The corresponding experiments have also been carried out, and the experimental results agree well with the simulation. The inline containments sensor based on OM has potentially wide sensing range for many kinds of determinate absorptive materials.