Flexible method for generating needle-shaped beams and its application in optical coherence tomography.

Area of Science:

• Optics and Photonics
• Biomedical Imaging

Background:

• Needle-shaped beams (NBs) offer extended depth-of-focus (DOF) crucial for high-resolution microscopy.
• Existing methods for generating NBs are often inflexible and difficult to implement.
• A universal and adaptable NB generation technique is needed to advance microscopy applications.

Purpose of the Study:

• To develop a common and flexible platform for generating customized needle-shaped beams (NBs).
• To enable precise control over NB parameters like length, diameter, and axial intensity.
• To demonstrate the application of these NBs in enhancing optical coherence tomography (OCT) imaging.

Main Methods:

• Development of a spatially multiplexed phase pattern for generating multiple, closely spaced axial foci.
• Utilizing this pattern as a universal platform for designing various NBs with tunable properties.
• Integration of the generated NBs into an optical coherence tomography (OCT) system.

Main Results:

• Successful creation of NBs with controllable length, diameter, uniform axial intensity, and sub-diffraction-limit characteristics.
• Demonstrated extension of the DOF in an optical coherence tomography (OCT) system using the novel NBs.
• Achieved high-resolution imaging of human epidermis, dermal-epidermal junction, and Drosophila larval heartbeat over large depth ranges.

Conclusions:

• The developed spatially multiplexed phase pattern provides a universal and flexible method for generating customized needle-shaped beams (NBs).
• This technique significantly enhances the depth-of-focus (DOF) of imaging systems like OCT.
• The improved imaging capabilities enable detailed visualization of biological structures and dynamics across extended depths.