Laser damage measurement techniques for the femtosecond regime

Abstract

Laser-induced damage is defined as any permanent laser-induced change in the characteristics of a sample. This change can be observed by many different inspection techniques, with different sensitivity, depending on the intended objectives and available techniques. The damage threshold definition and measurement are therefore very subjective and related to the detection method. The choice and implementation of a damage test system is then a critical issue on any experiment. In this work we present some implementation of detection techniques for laser damage metrology in the sub-picosecond regime. Different damage testing methods that have been applied will be discussed in view of their potential applications for testing functional optical components or to study physical process in the femtosecond regime, particularly the role of defects: optical microscopy, phase microscopy and time-resolved microscopy.

Development of a defect recognition algorithm for visual laser-induced damage detection

“…Therefore, in-situ online monitoring of key optical components is important, especially for high energy applications, such as inertial confinement fusion or plasma physics (National Ignition Facility, Mercury Laser, Omega EP). Optical and phase imaging microscopic techniques have an advantage in sensitivity and reliability over other damage detection methods [5]. However, microscopic investigation is time consuming and subjective in nature if the images are evaluated by a human operator.…”