Comparing the laser-induced damage distribution in POFs with raytracing simulations

authored by

Kevin Kiedrowski, Mario Ferraro, Raphael Jauberteau, Stefan Wabnitz, Maria Caterina Crocco, Vincenzo Formoso, Marco Jupé, Detlev Ristau

Abstract

The understanding of the laser-induced damage behavior in polymer optical materials is of high interest to prevent their damage and to increase the laser damage resistance of optical components. Moreover, compared with optical components made from high-quality glass materials, nanosecond laser-induced damage for wavelengths in the visible and near-infrared (NIR) occurs inside the bulk material of PMMA and not at its surface. This phenomenon complicates the determination of the laser-induced damage threshold (LIDT) in PMMA fibers. Since the bulk material itself determines the LIDT, knowledge of the intensity distribution in the multimode fiber is of utmost importance. Our fibers were irradiated at a wavelength of 532 nm with an ns-pulsed laser system with a 10 Hz repetition rate. To investigate the damage behavior in polymer optical fibers, we applied different imaging and analysis techniques. To our knowledge, those techniques are used here for the first time in order to study damaged polymer materials. With the help of a Nomarski microscope, axial and radial damage distributions within the multimode PMMA fibers were determined and compared with ray-tracing simulations of the intensity distribution within the optical fiber. Moreover, extruded PMMA plates were irradiated with the aim of comparing the damage behavior of materials with different manufacturing. In addition, the planar geometry of the plates allows for a more reliable application of the different measurement methods. Overall, investigations with a thermal imaging camera and EDX analysis indicate that the damage behavior of polymer optical material is thermally driven during the ns-pulsed irradiation. Furthermore, voids are formed during the damaging process within the polymer optical fibers and plates, as indicated by both SEM images and X-ray computed microtomography (µ-CT) investigations. Finally, we investigated the damages in fiber preforms and PMMA plates using two photon-microscopy. By doing this, we detected fluorescence signals from the damaged material, indicating that the damage process leads to a major modification of the polymer.

Organisation(s)

Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines

External Organisation(s)

Laser Zentrum Hannover e.V. (LZH)
Sapienza Università di Roma
University of Calabria

Type

Article

Journal

Optical materials express

Volume

14

No. of pages

16

ISSN

2159-3930

Publication date

30.04.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials

Electronic version(s)

https://doi.org/10.1364/OME.520782 (Access: Open)