Focusing of light through a stratified medium: a practical approach for computing microscope point spread functions: Part II: confocal and multiphoton microscopy

We propose a rigorous and easy to use model to compute point spread functions of confocal and multiphoton microscopes imaging through a stratified medium. Our model is based on vectorial theories for illumination and detection, combined with the simple ray-tracing method of Gibson and Lanni to calculate the aberration function. We show the validity of this approach, which is always very precise for biological applications, and exact in the case of a single interface. For mediums with very large index of refraction gaps, small discrepancies appear between rigorous vectorial theories and our simplified model. Our model may also be used to precisely compute point spread functions of 4-Pi and STED microscopes.

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