Exploration for adequate non-diffractive beam generation in dense scattering media.

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Scattering Media Physics

Background:

• Non-diffractive beams (NDBs) are crucial for optical sensing, but their application in scattering media, especially for macroscopic imaging in living tissues, remains challenging.
• Existing NDB propagation methods are optimized for microscopic imaging, limiting their depth penetration and resolution in complex biological environments.

Purpose of the Study:

• To develop an experimental approach for generating adequate NDBs in dense scattering media for macroscopic sensing up to tens of centimeters deep.
• To establish a method for estimating the maximum center intensity ratio of NDBs at any propagation distance within scattering media.

Main Methods:

• Utilized the linear relationship between propagation distance and transport mean free path to generate NDBs in dense scattering media.
• Employed annular beams with varying diameters to investigate NDB propagation characteristics.
• Conducted experimental measurements and theoretical analysis to validate the findings.

Main Results:

• Demonstrated a consistent change in the center intensity ratio of NDBs for annular beams of different diameters.
• Successfully generated adequate NDBs in dense scattering media for macroscopic sensing applications.
• Developed a method to estimate the maximum center intensity ratio of NDBs at arbitrary propagation distances.

Conclusions:

• The proposed experimental approach effectively generates NDBs suitable for macroscopic sensing in living tissues.
• The findings provide a theoretical and experimental basis for predicting NDB behavior in scattering media.
• This research advances optical sensing capabilities for deep-tissue imaging and diagnostics.