Imaging through a square multimode fiber by scanning focused spots with the memory effect.

Area of Science:

• Optics and Photonics
• Waveguide Technology
• Biomedical Imaging

Background:

• A shift-shift memory effect in square waveguides was previously observed using correlation measurements.
• This effect describes how input field translations induce symmetrical output field translations.

Purpose of the Study:

• To demonstrate the shift-shift memory effect in real space for imaging applications.
• To utilize this effect for fluorescence imaging through multimode fibers without transmission matrix measurements.

Main Methods:

• Wavefront shaping using guide-star feedback to create a focus at the output of a square-core multimode fiber.
• Exploiting the shift-shift memory effect to scan four symmetrical spots at the fiber output by shifting the input wavefront.

Main Results:

• The shift-shift memory effect was successfully demonstrated in real space.
• A method for fluorescence imaging through a multimode fiber was developed, leveraging the memory effect.
• The imaging technique eliminated the need for measuring a transmission matrix.

Conclusions:

• The shift-shift memory effect is a viable phenomenon for real-space imaging applications.
• Wavefront shaping and the memory effect enable efficient fluorescence imaging through multimode fibers.
• This approach offers a simplified method for imaging in complex optical systems.