Compact extended-DOF microscope through electrowetting lens

Area of Science:

• Optical Microscopy
• Microscope Instrumentation
• Electrically Tunable Lenses

Background:

• Optical microscopy faces a resolution-depth of field (DOF) trade-off, limiting 3D sample observation to a few micrometers.
• Mechanical scanning to increase DOF is slow and can cause vibrations in delicate samples.

Purpose of the Study:

• To propose a novel extended-DOF microscope design using an electrically tunable lens (ETL) to overcome the limitations of traditional microscopy.
• To develop a compact microscope architecture capable of capturing extended depth image stacks.

Main Methods:

• An electrically tunable lens (ETL) based on electrowetting was integrated into a compact microscope setup.
• Axial scanning was achieved through non-afocal coupling of two M12 lenses and the ETL.
• The system was designed as a potential add-on module for commercial microscopes.

Main Results:

• The proposed extended-DOF microscope achieved a long depth range with constant magnification and resolution comparable to standard microscopes.
• Spatial resolution remained invariant across the entire depth range.
• The compact design maintained high optical performance.

Conclusions:

• The ETL-based extended-DOF microscope offers a viable solution for imaging thicker 3D samples without mechanical scanning.
• The proposed system's compact and adaptable design allows for integration with existing microscopes, enhancing their capabilities.