The Linearized Research On Integrated Optical Waveguide Pulsed Electric Field Sensing Signal

Compared to traditional electric field sensor, integrated optical waveguide electric field sensor which is widely used in the measurement of electric field, has many advantages, such as small volume, wide bandwidth and the powerful ability to resist electromagnetic interference. In practical environment, the working point of electric field sensor will be easily influenced by temperature, stress, illumination and so on. And this results in that the electric field sensor cannot operate with optimum working point and the distortion of the output. On the other hand, in practical, the components used in the system and the surroundings can bring noise to the output signal, this makes a great influence to the accuracy of the signal.In allusion to the signal distortion resulted from the drifting character of the sensor, this thesis put forward nonlinearity compensation algorithm to distorted signal with the purpose of keeping the linear relation between the input and the output And In allusion to the output which is polluted by noise, this thesis realized the noise reduction of waveform by means of Labview which is a kind of software. The main contents of the thesis are as follows:1. This paper analyzed the operating principle and the distortion performance of the electric field sensor. On the basis of theoretical analysis of it, this thesis adopt the nonlinearity compensation algorithm to distorted signal. Due to the transmission characteristic of electric field sensor, when the sensor is working on without electric field signal,output signal is a direct current signal which is a function of offset working point in current time. When the transient pulse electric field signal affects the electric field sensor, the direct current signal of current output is a function of offset working point of sensor approximately. FFT(Fast Fourier Transformation) algorithm is used for extracting direct current signal from distorted signal.2. Nonlinearity compensation algorithm is studied firstly in the VPI(VPItransmissionMaker) simulation platform. The lightning impulse and gaussian pulse are used as particular cases of subtle pulse and nanosecond pulse. The paper set up the simulation framework and simulates the distortion performance of the sensor in actual environment. In use of the joint simulation between the VPI and Matlab, the paper realized nonlinearity compensation for distorted signal and at the same time the evaluation and analysis of the simulation data has been done from the changes of waveform parameters.3. The method of wavelet denoising and average-filtering has been firstly used for decreasing the noise of experimental data, involving hybrid programming between Labview and Matlab. Secondly, programming has been done in Labview platform to reduce the noise of output signal in experimental environment. Lastly, nonlinearity compensation algorithm is implemented of the denoising data in the purpose of wave recovery.