Polarization-maintaining dispersion-compensation microstructure fiber
A polarization-maintaining dispersion-compensation microstructure fiber includes an inner core, an air-hole array in area 1 and an air-hole array in area 2 . The air holes in the area 1 and 2 air-hole arrays are arranged in square lattice. The air-hole arrays in areas 1 and 2 are dislocated by half-layer along y-direction. In area 1 , 2 air holes in the middle row are omitted to form a solid area as the inner core. 2 outer cores are located in 2 sub-areas of area 2 , and each outer core contains 2 air holes. The long (or short) axes of the inner and outer cores are perpendicular, and the center points of the inner core and the two outer cores are located on the x-axis.
1. A polarization-maintaining dispersion-compensation microstructure fiber, wherein pure silica glass is used as a base material; the fiber comprises an inner core, a single-layer air-hole array surrounding the inner core, an inner cladding air-hole array, an air-hole array in an outer core, a single-layer air-hole array surrounding the outer core, and an outer cladding air-hole array; the single-layer air-hole array surrounding the inner core and the inner cladding air-hole array are collectively referred to an air-hole array in a first area; the air-hole array in the outer core, the single-layer air-hole array surrounding the outer core, and the air-hole array in the outer core are collectively referred to an air-hole array in a second area;
the air-hole array in the first area includes 3 rows of air holes arranged in a square lattice arrangement with an adjacent air hole spacing Λ; in the first area, two air holes in a middle row are omitted to form the inner core; a midpoint of a line connecting centers of the two omitted air holes are defined as a coordinate original point; an axis connecting the centers of the two omitted air holes is defined as y-axis; an axis passing through the original point and perpendicular to the y-axis is defined as the x-axis; a diameter of the air holes in the single-layer air-hole array surrounding the inner core is d1; the air holes in the air-hole array in the second area are arranged in square lattice arrangement with the adjacent air hole spacing Λ; the second area contains two sub-areas that are located outside the first area in the x-direction; the air-hole arrays in the first and second areas are separated by Λ along x-direction, and dislocated by Λ/2 along y-direction; two outer cores are respectively located in the two sub-areas of the second area and are symmetrically distributed with respect to the y-axis; the two outer cores have an identical structure; each of the two outer cores contains the air-hole array in the outer core and each air-hole array in the outer core comprises two air holes with a diameter d3; four air holes with the diameter d3 are located on a positive x-axis and a negative x-axis respectively, with distances of 3Λ and 4Λ measured from the centers of the air holes to the original point, respectively; a diameter of the air holes in the single-layer air-hole array surrounding the outer core is d2; a diameter of the air holes in the inner cladding air-hole array and the outer cladding air-hole array are both d4; the four diameters satisfy the relationship of d1>d2>d4>d3.
2. The fiber according to claim 1 , wherein the air holes in the air-hole array in the first area and the air-hole array in the second area use the adjacent air hole spacing Λ in a range of 2.288-2.298 μm.
3. The fiber according to claim 1 , wherein the diameter d1 of the air holes in the single-layer air-hole array surrounding the inner core is in a range of 1.601-1.611 μm.
4. The fiber according to claim 1 , wherein the diameter d3 of the two air holes included in the air-hole array in the outer core is in a range of 0.224-0.234 μm.
5. The fiber according to claim 1 , wherein the diameter d2 of the air holes in the single-layer air-hole array surrounding the outer core is in a range of 1.372-1.382 μm.
6. The fiber according to claim 1 , wherein the diameter d4 of the air holes in the inner cladding and the outer cladding air-hole arrays is in a range of 1.055-1.065 μm.
7. The fiber according to claim 1 , wherein the inner cladding air-hole array directly above or below the single-layer air-hole array surrounding the inner core contains more than 1 row of air holes; and the two sub-areas of the air-hole array in the second area contains more than 5 rows and 5 columns of air holes.