Methods and challenges in laser-induced damage threshold evaluation of volumetric photopolymerized micro-structures

The spread of micro-optical elements fabrication by femtosecond 3D nanolithography is limited due to lack of available optically resilient photopolymers. We have conducted S-on-1 laser-induced damage threshold (LIDT) measurement experiment with two different photopolymers, which demonstrated varying damage probability distribution after which suitable linear approximation technique was not evident. Moreover, different optical damage mechanisms were present during laser irradiation of diverse photopolymers that featured different chemical composition and physical properties. Seeking to determine reliable LIDT evaluation method which would provide trustworthy results for all the investigated materials, we have used three different ISO standard-like approaches. Results comparison for two different cases was conducted concluding that linear approximation of input fluencies range where optical damage probability is 0%<P<100% provides the lowest LIDT value for discussed examples, at the same time showing consistent and suitable for practical applications results.