Presentation
5 March 2021 Free-electron and thermally mediated pathways of photodamage in nonlinear microscopy
Author Affiliations +
Abstract
Photodamage in nonlinear microscopy of transparent tissues starts at irradiances 1.5 times above the autofluorescence imaging level. Although the free-electron density is low, their energy suffices to break bonds in water, DNA and the backbone and side chains of proteins. We explored photodamage kinetics using physical indicators (hyperfluorescence, plasma luminescence, bubble formation). By plotting threshold values in (irradiance/radiant exposure) space, we identified a “safe” region for microscopy. Thermomechanical effects become relevant in melanin-containing tissue. Two-photon excitation of retinal fluorophores allows monitoring metabolic transformations. We analyze the thermomechanical damage pathways in retinal imaging, and discuss strategies for mitigating such damage.
Conference Presentation
© (2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alfred Vogel, Xiao-Xuan Liang, Sebastian Freidank, and Norbert Linz "Free-electron and thermally mediated pathways of photodamage in nonlinear microscopy", Proc. SPIE 11648, Multiphoton Microscopy in the Biomedical Sciences XXI, 1164806 (5 March 2021); https://doi.org/10.1117/12.2583102
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KEYWORDS
Microscopy

Tissues

Electrons

Luminescence

Plasma

Retina

Skin

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