Research On Faraday Effect In Magneto-optic Glass Fiber And Its Application In All-fiber Current Transducer

Faraday effect in magneto-optic glass fiber and its application to all-fiber current transducer are studied in this thesis.The distribution of electromagnetic field in single-mode fiber is analyzed, the theory of Faraday effect in magneto-optic glass fiber is clarified and the rules of Faraday effect are concluded in this thesis. We derive the relationship between Verdet constant of magneto-optic glass and operating wavelength by the dispersion theory of Verdet constant. ZF1 and ZF6 magneto-optic glass are experimentalized to testify the relationship. The experimental results are in agreement with the theory. The polarization properties of ZF1 magneto-optic glass fiber are studied by experiment and the sources of errors are analyzed. We draw a conclusion that magneto-optic glass fiber is applicable to be made into all-fiber current transducer to measure electric current and magnetic filed.The propagation properties of linearly polarized light in single-mode fiber are introduced in brief in this thesis. The depolarization phenomena of multi-mode fiber for communication and magneto-optic glass multi-mode fiber are experimented. The fundamental principles and configuration of a sort of all-fiber current transducer are introduced in this thesis.The second half part of this thesis studies some critical components of a pragmatic all-fiber current transducer. The range of light wavelength that dichroism polarizer is effective is studied experimentally in this part. The conception of two types of polarizer of multi-layer medium films is brought forward in this part. The principles of the application of these two polarizers to all-fiber current transducer are analyzed theoretically, and then experiments are performed to testify. We use the rod-in-tube method to draw the ZF1 magneto-optic glass into optical fiber. The factors of choosing light sources that are applicable to all-fiber current transducer are considered in this part. The principles of two schemes of signal detection that can be employed in all-fiber current transducer areABSTRACTanalyzed. The influence on all-fiber current transducer of linear birefringence in optical fiber is analyzed and partial resolvents are concluded in this part too.At the end of this thesis, we picture the nice prospect of all-fiber current transducer when it is used in the department of electric power, and some problems that should be solved when all-fiber current transducer is utilized pragmatically are summed up.