High Flattened Comb Filter with Precise Channel Spacing Based on Linearly Chirped Fiber Bragg Grating and Phase Compensation |
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| Authors: | Sun Guodan Wang Rong Pu Tao Wei Zhihu |
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| Institution: | Institute of Communication Engineering, PLA University of Science, and Technology , Nanjing , China |
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| Abstract: | Abstract A novel approach to implement high flattened comb filters with precise channel spacing based on DC phase compensation is proposed. Channel wavelength error and peak reflectivity variation are discussed and calculated. A phase compensation method by simply changing the DC refractive index is proposed. Fiber Bragg gratings with different DC phase shifts are fabricated, which indicates that an arbitrary DC phase shift can be introduced precisely. A high flattened comb filter with precise 50-GHz channel spacing is realized with the help of a micrometer-precision translation stage. Then the peak reflectivity variation with and without phase compensation for different chirp coefficients is researched. |
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| Keywords: | optical communication fiber Bragg grating comb filter peak reflectivity variation DC refractive index modulation phase shift |
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