The Measurement System of Birefringence and Verdet Constant of Optical Fiber
The Faraday magneto-optical effect of optical fiber has many applications in monitoring magnetic field and electric current.When a linearly polarized light propagates in the direction of a magnetic field,the plane of polarization will rotate linearly proportional to the strength of the applied magnetic field,which following the relationship of θF =VBlθF is the Faraday rotation angle,which is proportional to the magnetic flux density B and the Verdet constant V.However,when the optical fiber contains the effect of linear birefringence,the detection of Faraday rotation angle will depend on the line birefringence.In order to determine the Verdet constant of an optical fiber under a linear birefringence,the fiber birefringence needs to be accurately measured.In this work,a model is applied to analyze the polarization properties of an optical fiber by using the Jones matrix method.A measurement system based on the lock-in amplifier technology is designed to test the Verdet constant and the birefringence of optical fiber.The magnetic field is produced by a solenoid with a DC current.A tunable laser is intensity modulated with a motorized rotating chopper.The actuator supplies a signal as the phase-locked synchronization reference to the signal of the lock-in amplifier.The measurement accuracy is analyzed and the sensitivity of the system is optimized.In this measurement system,the Verdet constant of the SMF-28 fiber was measured to be 0.56±0.02 rad/T·m at 1550nm.This setup is well suitable for measuring the high signal-to-noise ratio(SNR)sensitivity for lock-in amplifier at a low magnetic field strength.
Faraday effect Verdet constant Birefringence magneto-optic optical fiber
Yi Huang Li Chen Qiang Guo Fufei Pang Jianxiang Wen Yana Shang Tingyun Wang
Key laboratory of Specialty Fiber Optics and Optical Access Networks,School of Communication and Information Engineering,Shanghai University 149 Yanchang Road,Shanghai 200072,China
国际会议
2013 International Conference on Optical Instrument and Technology (OIT’2013)(2013年光学仪器与技术国际会议)
北京
英文
1-7
2013-11-17（万方平台首次上网日期，不代表论文的发表时间）