Graded arc beam in light needle microscopy for axially resolved, rapid volumetric imaging without nonlinear processes

Area of Science:

• Biomedical Optics
• Microscopy
• 3D Imaging

Background:

• High-speed 3D imaging is crucial for understanding biological structures and functions.
• Confocal laser scanning microscopy is widely used but involves slow image stacking.
• Previous light needle microscopy was limited to multiphoton excitation due to Bessel beam sidelobes.

Purpose of the Study:

• To introduce a novel light needle beam for 3D imaging.
• To enable rapid 3D imaging in one-photon excitation fluorescence microscopy.
• To overcome artifacts associated with Bessel beam sidelobes.

Main Methods:

• Developed a new beam generating a needle spot without sidelobe artifacts.
• Applied this beam to one-photon excitation fluorescence 3D imaging.
• Demonstrated real-time 3D observation of nanoparticles and neuronal structures.

Main Results:

• Achieved real-time 3D observation of 200-nm particles at over 50 volumes/second.
• Successfully visualized fine neuronal spine structures in fixed mouse brain tissue.
• The method is compatible with various biological imaging modalities.

Conclusions:

• The proposed light needle beam facilitates rapid 3D imaging in one-photon excitation microscopy.
• This technique overcomes previous limitations, enabling faster and artifact-free biological imaging.
• Offers broad applicability for high-speed 3D image acquisition in diverse biological studies.