Determination Of Photonic Crystal Fibers’ Azimuthal Angle Based On The Light Intensity Characteristics

Determination of azimuth angle of photonic crystal fiber is essential in the fabrication of devices based on photonic crystal fiber. Using side polishing technique tophotonic crystal fiber, theoretical studies show that: with the change of photonic crystal fiber’s side polishing position, and polishing depths, its internal characteristics of the transmitted light will change, they can achieve different modes of optical transmission in a photonic crystal fiber and show different performance. In the fabrication of photonic crystal fiber devices, determining accurately the azimuth angle of photonic crystal fibers is an important technology, based on the experimental study and theoretical calculations, we propose a high accuracy method to photonic crystal fiber’s azimuth angle‐a method of characteristics judgment of light intensity.Hexagonal PCF、Hybrid and LAM‐20have been researched in experimental studies，the results show that the light intensity characteristics in side image changes in corresponding with the rotation of azimuthal angel，which could be applied to determine the azimuthal angle. With the rotation of photonic crystal fiber, experimental results show the light intensity changes periodically, the photonic crystal fibers themself have theirown cyclical and structural characteristics of symmetry, the experimental light intensity’s period is in corresponding to the photonic crystal fiber’s Air holes’s period, by extracting the feature value of the light intensity at different axial orientation angle, the experimental characterictic value of the photonic crystal fiber show maxima, which verifies the symmetry between the experimental characterictic value and the azimuthal angle. Accordingly to the experimental result, we propose a method to determine the photonic crystal’s azimuthal angle‐side light intensity characteristic value method.With Tracepro simulation software, simulation of photonic crystal fibers’s ray tracing verifies the existence of photonic crystal fiber side light intensity characteristics, and with the rotation of fibers, the light intensity characteristic value is also changed, the variation of azimuthal characteristic values show the same period, and the light intensity characteristic value changes with the fiber’s ratation, the light intensity values also show periodical characteristic maxima, the comparison of the simulation and experimental results show that in particular azimuthal angle, the intensity eigenvalues axial position of the azimuth can be used to determine the photonic crystal fiber’s azimuthal angle, this could be used to verify the correctness of the side light intensity characteristic value method.Side intensity eigenvalues discrimination law has lossless, online, non‐contact to determine photonic crystal fiber’s azimuth angle, and this method could be highly accurate in determining photonic crystal fiber’s azimuthal angle, and the accuracy can be reaches1°.