Effects of inhomogeneous fields in superresolving structured-illumination microscopy.

Area of Science:

• Microscopy and Imaging Science
• Optical Physics
• Biophysics

Background:

• Structured illumination microscopy (SIM) enhances resolution by down-converting high spatial frequencies.
• High-contrast, high-frequency illumination patterns are crucial for effective SIM.
• High numerical aperture (NA) objectives are often used to generate these patterns.

Purpose of the Study:

• To investigate the generation of high-frequency illumination patterns using high NA objectives (1.42 NA and 1.65 NA) in SIM.
• To analyze the impact of inhomogeneous illumination fields on super-resolution imaging.
• To identify methods for avoiding adverse effects caused by inhomogeneous fields.

Main Methods:

• Utilizing high NA microscope objectives (1.42 NA and 1.65 NA) in a structured illumination microscopy setup.
• Characterizing the spatial frequency content and homogeneity of the generated illumination patterns.
• Evaluating the performance of super-resolution imaging under conditions of inhomogeneous illumination.

Main Results:

• High NA objectives can generate relatively high-frequency illumination patterns necessary for SIM.
• These high-frequency patterns can become evanescently decaying, leading to inhomogeneous illumination within the sample.
• Inhomogeneous illumination fields were shown to negatively impact super-resolution imaging quality.

Conclusions:

• While high NA objectives facilitate high-frequency pattern generation in SIM, their use can introduce field inhomogeneities.
• Understanding and mitigating the effects of these inhomogeneous fields is essential for optimal super-resolution imaging.
• Strategies exist to avoid the adverse impacts of evanescently decaying illumination patterns in high-NA SIM.