Miao Xinxiang

Explanation of Laser-Induced Damage Behavior of Fused Silica in a Large-Aperture Laser using a Small-Aperture Damage Test

Laser-induced damage is a key lifetime limiter for optics in large laser facilities. Fused silica is tested to find the damage threshold on two different laser facilities of different apertures. The damage threshold shows that the corners of the component are less damage resistant. The acid etch on a corner does not effectively increase the damage threshold. A statistics-based model is presented to extrapolate the threshold data in a small-aperture test to predict the damage threshold under functional conditions.

Liquid Concentration Sensing Properties of Microfibers with a Nanoscale-Structured Film

A type of compact solution concentration sensor based on a microfiber with a nanoscale-structured film is proposed and demonstrated experimentally Additional loss at different solution concentrations is calculated by means of the three-dimensional finite-difference time-domain (3D-FDTD) method. The microfiber is fabricated by using the flame-heated scanning technique. Nanoscale-structured film is coated on the microfiber surface, which is assembled as a sensing unit. The sensitivity of this kind of sensor increases with the decreasing diameters of the microfiber. When the diameter of the microfiber is 2 ?m, a minimum concentration sensitivity of 1% (under 450 s measuring time) is demonstrated in the experiment. Higher sensitivity can be attained when the solution concentration is higher. The sensing properties of this microfiber with the nanoscale-structured film may provide opportunities for new applications in optical sensing devices.