Determination of porcine corneal layers with high spatial resolution by simultaneous second and third harmonic generation microscopy.

We describe a dual, second harmonic generation (SHG) and third harmonic generation (THG) microscope, with the aim to obtain large-scale images of the cornea that can simultaneously resolve the micron-thick thin layers. We use an Ytterbium femtosecond laser as the laser source, the longer wavelength of which reduces scattering and allows simultaneous SHG and THG imaging. We measure one-dimensional SHG and THG profiles across the entire thickness of pig cornea, detected in both the forward and backward directions.

Efficient selection of focusing optics in non linear microscopy design through THG analysis.

A theoretical and experimental study of the THG signal from a reference interface in confocal microscope allows precise analysis of beam propagation and optimization of the focusing objectives.