Remote Focusing in a Temporal Focusing Microscope

Area of Science:

• Microscopy
• Optical Physics
• Biomedical Imaging

Background:

• Temporal focusing microscopy enables axial scanning of the focal plane via dispersion.
• Conventional methods require physical stage movement, limiting speed and applicability.
• Current systems focus on a single depth at a time on a fixed camera.

Purpose of the Study:

• To demonstrate remote focusing in a temporal focusing microscope.
• To enable dynamic axial scanning of the focal plane without mechanical sample movement.
• To achieve image stack acquisition equivalent to traditional methods.

Main Methods:

• Utilized an electrically tunable lens (ETL) within a 4f pulse shaper for dispersion tuning.
• Employed a second ETL in the detection path to maintain focus on the shifted excitation plane.
• Acquired image stacks by axially scanning the focal plane using the ETLs.

Main Results:

• Successfully demonstrated remote focusing capability in the temporal focusing microscope.
• Achieved axial scanning of the excitation plane using dispersion tuning via an ETL.
• Maintained focus on the shifted excitation plane using a second ETL, allowing image acquisition at different depths.
• Image stacks generated using the dual-ETL system were found to be equivalent to those acquired via traditional stage scanning.

Conclusions:

• Remote focusing is feasible in temporal focusing microscopy using electrically tunable lenses.
• This method offers an alternative to mechanical stage scanning for axial image acquisition.
• The dual-ETL system provides equivalent performance to traditional stage scanning, enhancing imaging flexibility.