High-speed focusing and scanning light through a multimode fiber based on binary phase-only spatial light modulation

A binary phase-only modulation technique was proposed to focus and scan light through a multimode fiber (MMF) based on spatial light modulator (SLM). For the same number of modulation modes, the number of iterations using this method is only 1/256 of that using phase-only iterative optimization or 1/3 of that using phase-only computation optimization, and the modulation time is at least one to two orders of magnitude shorter than previous wavefront shaping systems. Focusing and scanning light through an MMF with a 105 μm core diameter and 5 m length was achieved experimentally. This method can be extended to focus and scan light at multiple planes along the axial direction by modifying the input wavefront accordingly.