Axial superresolution with ultrahigh aperture lenses

Area of Science:

• Optical microscopy
• Superresolution imaging
• Biophysics

Background:

• Axial resolution is critical for 3D imaging in microscopy.
• Existing optical sectioning microscopy methods face limitations in achieving higher axial resolution.
• Novel lens designs and pupil engineering offer potential for overcoming these limits.

Purpose of the Study:

• To investigate the limits of axial resolution in optical sectioning microscopy using a single lens.
• To enhance axial resolution by combining high numerical aperture (NA) oil immersion lenses with superresolving binary aperture filters.
• To quantify the axial resolution improvement achieved by these combined techniques.

Main Methods:

• Utilized novel 1.45 numerical aperture (NA) oil immersion lenses.
• Employed superresolving binary aperture filters.
• Implemented the system in a confocalized two-photon excitation microscope.
• Quantified axial resolution by measuring the full-width-half-maximum (FWHM).

Main Results:

• Achieved an increased semiaperture angle to a maximum of 72.8 degrees.
• Demonstrated an absolute gain in axial resolution through the use of binary pupil filters.
• The combined system achieved an axial resolution of 330 nm FWHM.
• This represents a 34% improvement in axial resolution compared to a standard 1.4 NA system.

Conclusions:

• The combination of high NA lenses and binary aperture filters significantly enhances axial resolution in optical sectioning microscopy.
• This approach pushes the boundaries of optical sectioning microscopy, enabling finer 3D imaging.
• The demonstrated 330 nm axial resolution offers improved capabilities for biological and materials science applications.