Time-of-flight 3D imaging through multimode optical fibers

Area of Science:

• Optics and Photonics
• 3D Imaging Technologies
• Biomedical Engineering

Background:

• Time-of-flight (ToF) 3D imaging relies on measuring laser pulse round-trip times.
• Conventional ToF systems use large optics (centimeters in diameter).
• Existing methods are limited in applications requiring miniaturized or flexible imaging systems.

Purpose of the Study:

• To demonstrate near-video-rate 3D imaging through multimode optical fibers.
• To enable depth-resolving capabilities in ultrathin microendoscopes.
• To explore applications in clinical and remote inspection.

Main Methods:

• Utilized wavefront shaping for aberration correction synchronized with a pulsed laser source.
• Implemented a scanning technique to capture ~23,000 points per second.
• Employed multimode fibers with a small core diameter (50 micrometers) and total aperture of a few hundred micrometers.

Main Results:

• Achieved near-video-rate 3D imaging through optical fibers.
• Successfully imaged moving objects several meters away from the fiber end.
• Demonstrated frame rates of approximately 5 Hz with a ~40 cm long, 50-micrometer core diameter fiber.

Conclusions:

• This technique significantly advances 3D imaging through miniaturized optical systems.
• The developed method provides far-field depth-resolving capabilities for microendoscopes.
• Expected to enable novel clinical and remote inspection applications.