The point spread function of optical microscopes imaging through stratified media

Area of Science:

• Optical microscopy
• Biophysics
• Image processing

Background:

• Accurate modeling of light propagation is crucial for optical microscopy.
• Existing models may not fully account for refractive index mismatches at interfaces.
• This can lead to inaccuracies in predicting microscope performance.

Purpose of the Study:

• To propose a novel model for imaging point objects through dielectric interfaces.
• To provide an analytical solution for various microscopy techniques.
• To highlight limitations of current models under specific conditions.

Main Methods:

• Development of a theoretical model for imaging through stratified media.
• Derivation of an analytical solution using readily computable functions.
• Analysis of illumination and detection point spread functions.

Main Results:

• The proposed model is applicable to conventional and confocal fluorescence microscopy (single- and multiphoton excitation).
• Significant differences in point spread functions were observed with large refractive index mismatches.
• Current imaging models may inaccurately predict microscope performance in such scenarios.

Conclusions:

• The new model offers a more accurate approach for understanding image formation in microscopy.
• It is essential to consider refractive index variations for precise optical microscope characterization.
• This work improves the predictive power of imaging models for complex optical systems.