Temperature‐Controlled Tunable Broadband Dispersion Compensation Photonic Crystal Fiber With High Birefringence for DWDM Transmission System

ABSTRACT In this article, a high birefringence tunable broadband dispersion compensation photonic crystal fiber (TB‐DC‐PCF) is proposed. Periodically triangular lattice air holes are arranged in the cladding of TB‐DC‐PCF. By reducing the diameter of the air holes in the third layer of the cladding, a weakly coupled double‐core structure is formed, which is conducive to the realization of broadband dispersion. In the first layer of cladding, the two air holes in the x direction are filled with temperature‐sensitive material to realize the dispersion tunable function. The symmetry of the core region is broken to make it highly birefringent, which avoids the crosstalk between polarization modes. The performances of TB‐DC‐PCF are numerically analyzed by the finite element method with perfect matching layer. The results show that the TB‐DC‐PCF has the birefringence of 2.26 × 10 ‐2 ~ 2.69 × 10 ‐2 at 1360 ~ 1625 nm wavelengths, and the dispersion of the x‐ and y‐polarized directional modes of − 309 ~ − 1140 ps/(nm·km) and − 68 ~ −222 ps/(nm·km), respectively. At 1550 nm, the dispersion compensation multiples of the x‐ and y‐polarization direction modes are up to 57.90 and 9.52, which enables simultaneous compensation of dispersion and dispersion slope for standard single‐mode fibers. In addition, the dispersion of TB‐DC‐PCF can be linearly varied with temperature within a certain range. At 1550 nm, the dispersion of the x and y polarization directions can be changed by 5.28 and 0.31 ps/(nm·km) per 1°C by controlling the temperature, respectively. The proposed TB‐DC‐PCF can be used for broadband dynamic dispersion compensation in the dense wavelength division multiplexing systems, the construction of passive all‐optical networks of sensing.