Fast Focal Point Correction in Prism-Coupled Total Internal Reflection Scanning Imager Using an Electronically...

Area of Science:

• Optical microscopy
• Surface science
• Biomedical imaging

Background:

• Total internal reflection (TIR) is a powerful technique for studying interfacial phenomena.
• Prism-coupled TIR imaging microscopes have limited sensing areas due to the interface's orientation.
• Mechanical scanning in microscopes introduces noise and drift.

Purpose of the Study:

• To introduce an electrically tunable lens for focal length correction in TIR microscopy.
• To enhance the sensing area and imaging capabilities of oblique-incidence scanning microscopes (OI-RD).
• To reduce mechanical movement and associated artifacts in TIR imaging.

Main Methods:

• Integration of an electrically tunable lens into a prism-coupled TIR geometry.
• Application in an oblique-incidence scanning microscope (OI-RD).
• Imaging a protein microarray to demonstrate performance.

Main Results:

• Successful rapid and reproducible focal length correction was achieved.
• An image of a protein microarray was acquired over a 4 cm² scan area.
• Effective resolution of less than 20 microns was demonstrated.

Conclusions:

• Electrically tunable lenses can effectively correct focal length in TIR microscopy.
• This method significantly expands the usable sensing area for interfacial analysis.
• Elimination of mechanical lens movement improves image quality by reducing noise and drift.