31results about How to "Improve scattering efficiency" patented technology

The invention discloses a large-core-diameter multimode optical fiber PDT light diffuser based on a torsion-tapering-etching composite structure, a preparation method and application, relates to the technical field of optical fiber devices for photodynamic therapy, and aims to solve the problems that in the prior art, light field distribution is uneven, wavelength adaptability is insufficient, and minimally invasive property and in-vivo stability are difficult to balance. According to the technical scheme, one end of a functional section is connected with a multimode optical fiber body, and the other end of the functional section is sequentially provided with a torsion part, a polishing and etching part and a tail end tapering part; a twisting-tapering-etching composite structure design is adopted; multi-mode coupling can be triggered when the optical fiber is twisted by 30 degrees, a low-order mode is converted into a high-order mode, a light field diffuses from the axis of the core layer to the edge, and a sufficient light field basis is provided for lateral light emitting; the tail end tapering changes the mode effective refractive index by narrowing the core diameter, more axial transmission light is promoted to be converted into a leakage mode to be emitted from the side direction of the conical surface, the total side light emitting power is improved through cooperation of the tail end tapering and the leakage mode, and sufficient light energy is provided for 630 nm PDT treatment.