What is an OPO?
Imaging thick tissue sections as well as whole animals plays a growing role in life science research. Obtaining spatial information in deep tissue areas is crucial to fully understanding biological processes. However, image quality decreases the deeper you image in the tissue, as light is scattered by biological specimens. Current methods allow light to reach about one hundred microns deep with standard widefield or confocal fluorescence microscopy by using excitation sources in the visible range. Unfortunately, it becomes impossible to penetrate hundreds of microns into the tissue while using visible light. Because light scattering is dependent on the wavelength, better tissue penetration can be achieved by using longer excitation wavelengths. This is where excitation with infrared light, two-photon processes, and the