High-speed optical coherence tomography by circular interferometric ranging.

Area of Science:

• Optical imaging
• Biomedical optics
• Metrology

Background:

• Existing 3D optical imaging struggles with large, dynamic fields, limiting applications in material inspection and medicine.
• Optical coherence tomography (OCT) is challenged by sparse scattering fields where most locations lack signal.
• Current OCT methods face signal acquisition barriers affecting speed and imaging field.

Purpose of the Study:

• To develop advanced optical coherence tomography (OCT) methods for efficient interrogation of sparse scattering fields.
• To overcome speed and field-of-view limitations in 3D OCT imaging for practical applications.
• To enable high-speed, large-volume 3D imaging in challenging environments.

Main Methods:

• Utilized frequency comb sources for optical subsampling, superimposing reflected signals from equispaced locations.
• Implemented circular ranging to reduce the number of required measurements for large volumetric fields.
• Developed an ultrafast, time-stretched frequency comb laser with 7.6 MHz to 18.9 MHz repetition rates.

Main Results:

• Achieved efficient interrogation of sparse scattering fields, a significant advancement for OCT.
• Successfully reduced signal acquisition barriers, enhancing both speed and field-of-view in OCT.
• Demonstrated 3D imaging of multi-cm³ fields at rates up to 7.5 volumes per second.

Conclusions:

• The developed OCT method enables efficient, high-speed 3D imaging of large, sparse scattering volumes.
• This technique overcomes critical limitations in current OCT systems, broadening its applicability.
• The advancements pave the way for improved material inspection, medical imaging, and other fields requiring large-scale 3D optical analysis.