Ti sapphire chameleon ultra laser

Upon completion of biaxial mechanical testing, the tissue samples were imaged using the SHG technique at the unloaded state. We utilized a Zeiss 710 NLO inverted confocal microscope (Carl Zeiss Microscopy, LLC, Thornwood, NY, USA), equipped with a mode-locked Ti:Sapphire Chameleon Ultra laser (Coherent Inc., Santa Clara, CA), a non-descanned detector (NDD), and a Plan-Apochromat 40× oil immersion objective. The laser was set to 800 nm and emission was filtered from 380–430 nm. Samples were kept hydrated with saline solution during imaging to prevent drying artifacts and covered with #1.5 coverslips. Samples were imaged inside the area delimited by the graphite markers, and 2D image slices were collected in the thickness direction from the smooth side of each sample. A 2D slice has 512×512 pixels to 1024×1024 pixels, and for each sample the number of slices was varied to cover the thickness. In total, we obtained 3D SHG images (size from 512×512×N to 1024×1024×N) of 48 tissue samples from different animal subjects, and the corresponding mechanical testing data. Representative SHG images of a GLBP sample are shown in Figure 2, with a total of 18 slices (N=18) through the thickness. It can be seen that geometry variation (e.g. fiber waviness) in each imaging plane is much larger than that in the thickness direction as shown in Figure 2.