Abstract: The present disclosure provides a hollow-core microstructure optical fiber preform, an optical fiber, and a method for manufacturing thereof. An objective of the present disclosure is to introduce a support sheet into a nested structure unit of the hollow-core microstructure optical fiber preform, which not only increases the number of reflection surfaces without increasing the number of nested layers of glass tubes, but also achieves a more accurate positioning by the support sheet and improves manufacturing accuracy as compared to a tangential structure of nested glass tubes, such that the following technical problems, difficulty in controlling a curvature of reflection surfaces, low manufacturing accuracy, large difference between actual loss and theoretical loss, or poor batch consistency, in related anti-resonance optical fibers, caused by increasing the number of layers of nested microstructure units in order to increase the number of reflection surfaces, are solved.

Abstract: A single-mode fiber with a large effective area comprises a core layer and a cladding layer. The core layer is cladded with an intermediate cladding layer, and a depressed cladding layer is provided outside the intermediate cladding layer. The core layer comprises a first fiber sub core layer having a radius r1 of 1.5-5 ?m and a relative refractive index difference ?n1 of 0.05-0.22%, and a second sub core layer having a unilateral radial width (r2?r1) of 1.5-5 ?m and a relative refractive index difference ?n2 of 0.15-0.34%, where ?n1 is less than ?n2. Accordingly, the optical fiber can reach an effective area equal to or greater than 120 ?m2 when the related parameters thereof are optimized.

Abstract: In one aspect of the invention, the bend insensitive single-mode optical fiber includes a core layer and cladding layers having an inner cladding layer, a trench cladding layer and an outer cladding layer sequentially formed surrounding the core layer from inside to outside. For the core layer, the diameter is 7-7.9 ?m, and the relative refractive index difference ?1 is between 4.6×10?3 and 6.5×10?3. For the inner cladding layer, the diameter is 16.5-20 ?m, and a relative refractive index difference ?2 is between ?3×10?4 and 3×10?4. For the trench cladding layer, the diameter is 33-40 ?m, and the relative refractive index difference ?3 is between ?2.9×10?3 and ?7.3×10?3, changes in a gradient manner and increases gradually from outside to inside, where a relative refractive index difference ?32 at an outermost interface is smaller than a relative refractive index difference ?31 at an innermost interface.

Abstract: A single-mode fiber with a large effective area comprises a core layer and a cladding layer. The core layer is cladded with an intermediate cladding layer, and a depressed cladding layer is provided outside the intermediate cladding layer. The core layer comprises a first fiber sub core layer having a radius r1 of 1.5-5 ?m and a relative refractive index difference ?n1 of 0.05-0.22%, and a second sub core layer having a unilateral radial width (r2?r1) of 1.5-5 ?m and a relative refractive index difference ?n2 of 0.15-0.34%, where ?n1 is less than ?n2. Accordingly, the optical fiber can reach an effective area equal to or greater than 120 ?m2 when the related parameters thereof are optimized.

Abstract: In one aspect of the invention, the bend insensitive single-mode optical fiber includes a core layer and cladding layers having an inner cladding layer, a trench cladding layer and an outer cladding layer sequentially formed surrounding the core layer from inside to outside. For the core layer, the diameter is 7-7.9 ?m, and the relative refractive index difference ?1 is between 4.6×10?3 and 6.5×10?3. For the inner cladding layer, the diameter is 16.5-20 ?m, and a relative refractive index difference ?2 is between ?3×10?4 and 3×10?4. For the trench cladding layer, the diameter is 33-40 ?m, and the relative refractive index difference ?3 is between ?2.9×10?3 and ?7.3×10?3, changes in a gradient manner and increases gradually from outside to inside, where a relative refractive index difference ?32 at an outermost interface is smaller than a relative refractive index difference ?31 at an innermost interface.