Focused light delivery and all optical scanning from a multimode optical fiber using digital phase conjugation

Abstract

We demonstrate a digital phase conjugation technique for generating a sharp focus point at the end of a multimode optical fiber. A sharp focus is experimentally obtained at the distal end of a 200µm core multimode fiber. By recording the digital holograms for different excitation conditions, the sharp focus can be digitally scanned over a 175µm diameter regular grid. The demonstrated technique is used for high resolution scanning lensless imaging based on multimode fibers, of stained biological samples that can enable diagnosis from the investigation of cellular phenotype.

Optical scanning endoscope via a single multimode optical fiber

“…Photorefractive crystals are wavelength-selective and have a slow response time. Besides, the optical phase conjugation setup is complex, often requiring two identical optical fibers, which can be challenging to achieve in practical applications 66 . Recently, the emergence of pixelated SLM has made the digital phase conjugation technique a preferred choice for wavefront corrections.…”

Color optical biopsy

“…Holographic microscopy in cellular imaging has emerged in recent years as a new tool for medical imaging application [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Current techniques allow imaging of very thin layers of scattering media.…”