High birefringence large non-linear photonic crystal fiber

Abstract

The invention provides a high birefringence large non-linear photonic crystal fiber. The high birefringence large non-linear photonic crystal fiber having a hexagonal crystal lattice oval air hole array structure composed of first oval air holes and second oval air holes and working in an intermediate infrared range from 3 [mu]m to 5 [mu]m includes a fiber core and a cladding disposed on an optical fiber background material. The cladding has six-layer hexagonal crystal lattice oval air hole arrays composed of first oval air holes and second oval air holes having identical long axis and different short axes. The second oval air holes are distributed along the y axis while the first oval air holes are distributed along the x axis. The fiber core is arranged in the solid area of the center position of the optical fiber background material. High birefringence of the optical fiber as high as 0.1177 is acquired in a wavelength range from 3 [mu]m to 5 [mu]m and the corresponding beat-length is 42.4 [mu]m. The nonlinear coefficient of the optical fiber in the x polarization direction and the y polarization direction is 38390w-1km-1 and 49760w-1km-1.

Description

Technical field [0001] The present invention relates to the technical field of mid-infrared optical fiber communication and optical fiber sensing, in particular to a high birefringence and large nonlinear photonic crystal fiber operating in the mid-infrared range of 3 μm to 5 μm. Background technique [0002] The fundamental mode transmitted in a single-mode fiber is composed of two degenerate orthogonal polarization modes. Under ideal conditions (the fiber is cylindrically symmetric and unstressed), these two orthogonal polarization modes are completely coupled . For actual optical fibers, due to the influence of gravity and internal residual stress during the drawing process, the shape of the core changes randomly along the length of the optical fiber, and the optical fiber no longer exhibits ideal cylindrical symmetry. As a result, the degenerate mode is destroyed. The two orthogonal polarization states have different propagation constants, which in turn causes the effective ...

AI Technical Summary

Problems solved by technology

However, the working wavelength (less than 3 μm) of the traditional photonic crystal fiber made of quartz material limits its application in the mid-infrared and far-infrared, and the nonlinear coefficient of the quartz material is small, making it difficult to realize the high nonlinear device. Miniaturization and Integration

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