Acquisition of Multi-Modal Images of Structural Modifications in Glass with Programmable LED-Array-Based Illumination

Ultrashort laser pulses can induce structural modifications in bulk glass, leading to refractive index change and scattering damage. As bright-field, dark-field, and phase imaging each provide complementary information about laser-induced structures, it is often desired to use multiple observations simultaneously. As described herein, we present the acquisition of bright-field, dark-field, and differential phase-contrast images of structural modifications induced in glass by femtosecond laser pulses with an LED array microscope. The contrast of refractive index change can be enhanced by differential phase-contrast images. We also report on the simultaneous acquisition of bright-field and dark-field images of structural modifications in a glass with LED-array-based Rheinberg illumination. A single-shot color image is separated to obtain bright field and dark field images simultaneously. We provide an experimental demonstration on multi-modal imaging of structural modifications in a glass with an LED array microscope using temporally-coded illumination and color-coded illumination.

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