General analysis and optimization strategy to suppress autofluorescence in microscope lenses

Area of Science:

• Optical Engineering
• Microscopy
• Materials Science

Background:

• Autofluorescence from optical glass in microscope lenses is a significant source of stray light, degrading image contrast in fluorescence microscopy.
• A thorough understanding of autofluorescence in various microscope lens designs and the factors influencing it remains unclear.
• Traditional simulation methods (volume scattering, Monte Carlo raytracing) are computationally intensive and time-consuming.

Purpose of the Study:

• To systematically analyze the autofluorescence effect in diverse microscope lenses using an efficient simulation method.
• To identify dominant factors contributing to autofluorescence and pinpoint critical lens elements responsible.
• To investigate and present effective strategies for reducing autofluorescence intensity in optical lens design.

Main Methods:

• Application of a phase-space-based simulation method for accelerated autofluorescence analysis.
• Simulation of over 100 microscope lenses with varying numerical aperture (NA), magnification, working distance, and immersion medium.
• Calculation of autofluorescence contribution from individual lens elements and systematic analysis of simulation results.

Main Results:

• Autofluorescence intensity is dependent on system etendue and complexity.
• Critical autofluorescence contributions originate primarily from the front and rear lens groups.
• The study identified specific lens elements as major contributors to autofluorescence.

Conclusions:

• The developed simulation method provides efficient analysis of autofluorescence in microscope lenses.
• Lens etendue, complexity, and specific element design critically influence autofluorescence.
• A guideline is provided for optical designers and users to select or design low-autofluorescence microscope lenses.