Breaking Abbe's diffraction limit with harmonic deactivation microscopy.

Area of Science:

• Nonlinear optics
• Microscopy
• Quantum optics

Background:

• Nonlinear optical microscopy enables label-free imaging but is limited by the Abbe diffraction limit.
• Existing super-resolution methods often require fluorescent labeling, limiting temporal resolution and applicability.

Purpose of the Study:

• To introduce a novel super-resolution technique for nonlinear microscopy that overcomes the Abbe diffraction limit without fluorescent labeling.
• To enable label-free imaging with enhanced resolution for biological and condensed matter systems.

Main Methods:

• Development of harmonic deactivation microscopy (HADES).
• Utilizing a second donut-shaped pulse to control quantum harmonic generation.
• Confining third-harmonic generation to below the diffraction limit of a scanning microscope.

Main Results:

• Demonstrated resolution improvement by deactivation in nonfluorescent samples.
• Showcased efficiency of resolution enhancement with higher harmonic orders.
• Identified deactivation-pulse fluence as the primary limitation for resolution.

Conclusions:

• HADES provides a route to break the diffraction limit in standard nonlinear microscopes.
• The technique offers potential for sub-100-nanometer resolution in label-free imaging.
• HADES expands the applicability of nonlinear microscopy to new frontiers.