Research On High Stability Semiconductor Laser And Dual Differential Optical Receiver Used For Polarization Type Optical Fiber Sensors

Optical fiber voltage transformer(OVT)is the use of electro-optical effect to measure the applied voltage.It has the advantages of small footprint,high measurement accuracy and good insulation performance.Fiber optic voltage transformers have been studied for about 40 years,but until now So far,no one has been able to meet the grid measurement standards and obtained the access certificate.The main reason for its development is the poor stability and low measurement accuracy of the current OVT system,which are related to the light source and the optical receiver.Therefore,the stable and cost-effective light source and the optical receiver capable of meeting the requirements of the measurement system are in the OVT.The system plays an important role and has great value in the development and research of the two.In this paper,high-precision constant temperature control and power stability control method are used to design and fabricate a semiconductor laser with polarization,wavelength and output power,which are suitable for polarized OVT.The control circuit and temperature control circuit are controlled by Labview.The feasibility of the method is proved by theoretical analysis and experiments.The experimental results show that the output wavelength control accuracy of the semiconductor laser is±0.01nm,the fluctuation range of the drive current is less than±0.05mA,and the output polarization ellipse The degree is 0.00(linear)and the direction angle fluctuation range is less than 0.1°.This shows that the wavelength,power and polarization stability of the laser meet the requirements of the fiber optic voltage transformer system.This paper also designs and produces a low noise and high precision analog dual differential optical receiver.It can receive two polarized lights perpendicular to each other to achieve high-precision polarization measurement.The experimental results show that when the signal-to-noise ratio is 1,the minimum measurement power is 800nw,the noise is less than 2mv,and the responsivity is 4900v/w,which satisfies the fiber.Requirements for voltage transformer systems.At the same time,it is possible to accurately measure the output light(spatial light)of the self-focusing lens,and the longest distance to find 3dB loss by constructing a measurement system is 11 cm.