Spatio-angular fluorescence microscopy II. Paraxial 4f imaging.

Area of Science:

• Optics and Photonics
• Biophysics
• Microscopy

Background:

• Fluorescence microscopy is crucial for biological imaging.
• Accurate interpretation of fluorescence data relies on understanding imaging system properties.
• Approximations in optical models can introduce biases in quantitative measurements.

Purpose of the Study:

• To analyze the imaging properties of a single-view fluorescence microscope in a 4f geometry without approximations.
• To investigate the system's spatio-angular band limit and its implications for simulations.
• To determine if out-of-plane fluorophore orientation information is captured and assess biases from the monopole approximation.

Main Methods:

• Theoretical analysis of a 4f fluorescence microscope.
• No monopole or scalar approximations were used.
• Exploitation of the identified spatio-angular band limit for efficient simulations.
• Investigation of fluorophore orientation effects on imaging.

Main Results:

• The 4f fluorescence microscope exhibits a spatio-angular band limit.
• This band limit allows for computationally efficient simulations.
• Paraxial fluorescence microscopes record information on the out-of-plane orientation of in-focus fluorophores.
• The monopole approximation can lead to biased fluorophore concentration estimates, though biases are minimal under specific sample conditions.

Conclusions:

• Single-view fluorescence microscopes in 4f geometry capture rich information beyond simple intensity.
• Understanding the spatio-angular band limit is key for accurate modeling and simulation.
• The study highlights the importance of avoiding approximations for precise quantitative fluorescence microscopy.