Sensing and Imaging with Multimode Fiber for Spatial Scanning

A team of Stanford engineers have developed a fast adaptive optics system for scanning, 3D imaging and sensing with a small (50 µm) multimode fiber (MMF). This technology uses a spatial light modulator (SLM) to manipulate the modes coupled at the MMF input in order to change the spatial focusing of light at the fiber output. Then an efficient algorithm reconstructs the optical field output into a 3D image with a wider field of view and higher resolution that current techniques. The system has applications in biological imaging, microscopy, sensing and optical communications. Because of the extremely small fiber probe, the invention may be particularly useful for imaging hard to reach locations in vivo.

This video shows a spot of light scanning across the output facet of a multimode fiber (MMF). When combined with a 3D image reconstruction algorithm, this adaptive optics system can be used for 3D imaging or sensor multiplexing.

Stage of Research
The inventors have demonstrated this technique for scanning microscopy and were able to distinguish between stripes 3.50 µm apart with axial resolution of 90 µm and depth of field of 200 µm. This invention motivated the application of MMF to high-resolution single-fiber microscopy/endoscopy (see Stanford Docket S12-501).