The Working Point Control Syetem In The 2D Electric Field Sensor Using M-Z Type Optical Interfrence

Compared with the electrical field sensor,the integrated Optical electric field sensor have strong resistance to the electromagnetic interference, high sensitivity, the advantages of small volume.So it is more suitable for being used in the field of the electric field measurement. With the development of optical sensor, the performance in the field of the measurement have been improved a lot after the production process improvement and system structure optimization. But in actual use process, the sensor based on the lithium niobate crystal as the core material of the M-Z optical interference sensor will produce working point drift problem. Working point drift problems will directly affect the space electric field signal measurement, so we need to control system’s working point to make the device in an appropriate state in the changing environment.For the working point of drift problem of the MZ type optical interference sensor during pulsed electric field. In view of the single light source drive two-dimensional electric field sensor system, the working point controlled system is designed in this paper. The system using the method of tuing the wavelength of the laser to control the work point.Then the waveform recovery was used to further improve the measurement precision. Besides the noise problem in the system is analyzed in the paper. The main research contents are as follows:1 The principle of the optical electric field sensor system working point drift have been presented, then the difference between the 1-D and 2-D system’s working point drift is analysed in the paper.2 According to the working point drift problem,the wavelength tunable light source and asymmetric type of optical waveguide MZ type device are adopted in the system. The point-set control circuit and the wavelength selection method are designed. The formula derivation and simulation is carried out for the system. The performance and the deficiency of the system are verified by experiments. Experiments show that the system can control the sensor in the stable state.3 In the case of the two devices drived by a single light, in order to solve the problem of the reduce of the sensing precision after the adopting of the above working point system. According to the characteristics of the pulsed electric field, the waveform optimization is used to improve the precision of the sensor waveform.This paper analyzes the principle of waveform recovery, and the experimental feasibility is verified. The analyze of the waveform after recovery shows that the precision of the electric field sensor waveform has improved.4 The noise is an important factor affecting the feasibility and accuracy in the experimental process which contains the system described and the waveform after the recovery process. The paper analyze the principle of the system noise, especially the backscattering noise and the polarization noise, which is verified by experiment. Then puts forward the method of noise suppression.