New High-power Optical Isolator Design And Experiment

Optical isolators is a optical passive device allowed signals to propagate in a forward direction. It is generally used to prevent unwanted back reflections from being transmitted back to a signal's source such as lasers and optical amplifiers。With the development of optical communication technology, the directions of compact configuration and low cost of optical isolators without polarization mode dispersion are expected.The paper is mainly based on developing a high-power optical fiber isolators. The brief description of the dissertation and some innovative places are presented as follows.1. It is introduced the development and tendency of the high-power Optical fiber isolators and contrasted several optical isolators without polarization mode, afterwards the principle and conformation of optical isolators is expounded. And then, we design a new structure of high-power optical isolator without polarization mode. The optical isolator component were introduced, analyzed and calculated.2. It is analyzed the important performance parameters of optical isolators theoretically, and showed the test method of the main performance parameters. The test results show that the isolator works well in the power of 45 W, the insertion loss is 0.7dB, the average isolation is 25dB, the highest average isolation is 30dB, the polarization dependent loss is less than 0.2dB, and the polarization mode dispersion is less than 0.1 ps.The innovation is:(1) After analyzing and calculating the C-lens, G-lens and A-lens, select C-lens as a collimator collimating lens and analyze the optical characteristics of their mass theoretically. Because of its uniformity refractive index, C-lens is suitable for long distance work and is the best choice for high-power devices. (2) During analyzing and comparing some kinds of magneto-optic materials, Use terbium Gallium Garnet as Magneto Optical Crystals, which has a bigger Faraday rotation coefficient in 1064nm, lower light loss, larger optical damage threshold, higher thermal conductivity and better mechanical properties. So it is a good material in high power devices.