Determining the bandgap dependence of nonlinear absorption and laser induced damage threshold through numerical simulation and experiment

authored by: Joshua McCauley, Xiaochuan Ji, Marco Jupé, Jinlong Zhang, Andreas Wienke, Detlev Ristau
Abstract: Nonlinear absorption is mainly governed by mechanisms involving excitation processes of electrons. Typically, two phenomena are considered when discussing nonlinear absorption; the multiphoton absorption where multiple photons interact directly with a single electron, and tunnel ionization, where the high electric field results in a shifting of the bandgap allowing an electron to tunnel into the conduction band. Electrons in the conduction band can be accelerated through the absorption of further photons until they obtain enough energy to excite further electrons to the conduction band, leading to runaway absorption and finally damage of the sample. By laser calorimetric measurement of the nonlinear absorption, it is expected that the laser damage threshold can be predicted without damaging the optic. Before accurate predictions can be made, the process must be thoroughly characterized and understood. The nonlinear behavior of the absorption was demonstrated with potential increases in absorption of an order of magnitude. Initial results show a noticeable impact of contaminants, though a nonlinear response is still observed.
Organisation(s): Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
External Organisation(s): Laser Zentrum Hannover e.V. (LZH)
Tongji University
MOE Key Laboratory of Advanced Micro-Structured Materials
Type: Conference contribution
No. of pages: 7
Publication date: 24.11.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1117/12.2685160 (Access: Closed)