Dissertation > Excellent graduate degree dissertation topics show

The Research and Controlling of the Modulation Performances of Electro-optic Modulator for the Distributed Brillouin Sensing System

Author: ZhangKai
Tutor: ZhangXuPing
School: Nanjing University
Course: Optical Engineering
Keywords: Optical fiber sensing Brillouin Optical Time Domain Reflectometer Electro-optic modulator Bias voltage control Digital Signal Processor
CLC: O437.2
Type: Master's thesis
Year: 2011
Downloads: 108
Quote: 0
Read: Download Dissertation

Abstract


Based on spontaneous Brillouin scattering optical time domain reflectometer (BOTDR) while the optical fiber as a sensing element and signal transmission medium , to detect the changes of the optical fiber along the temperature , stress , and other physical quantities , realize distributed measurement , in recent years cause of widespread concern . In the BOTDR system , spontaneous Brillouin scattering signal is very weak and the hundreds of GHz frequency , is not easy to directly detect . Using self-heterodyne coherent detection method can increase the signal strength of the Brillouin scattering , easy to get a good sensor measurement accuracy , but still has a very high center frequency of the signal directly to the Brillouin scattered light and the local reference light coherent obtained , resulting in subsequent signal processing difficulties . A viable option is the use of electro-optic modulator (EOM) to the local reference light microwave electro-optic modulation frequency shift to a frequency close to the Brillouin backscattered light , this time coherent signal center frequency of several hundred MHz, largely reducing the requirements on the photoelectric detector , easy - to - follow - up detection and handling . However , EOM , due to the inherent structure , susceptible to the influence of environmental factors such as temperature, stress , the drift of the operating point occurs , affected the BOTDR system measurement accuracy and measurement stability . The article summarizes abroad on EOM working point control method , conducted in-depth research to the selection of the operating characteristics of the EOM and EOM working point BOTDR system A method for the BOTDR in control EOM working point of the new method . This method uses a digital signal processor as the core of the hardware platform , with the stepping follow \This paper discusses the characteristics of the hardware system design and software algorithms to analyze the system performance , compared with the traditional the EOM working point control method . The experimental results show that this method can be effectively stabilized EOM working point , so that long-term stability of the EOM work in the working point of the high microwave modulation efficiency and high extinction ratio . This program applied to BOTDR system , get the stable local reference light , to ensure the accuracy of the Brillouin power spectrum measurement accuracy and system stability of BOTDR be promoted .

Related Dissertations

  1. The Research of Control System of Permanent Magnet Synchronous Motor Based on DSP,TM383.42
  2. A Novel Controller Design for Active Power Filter with Low Switching Loss,TN713.8
  3. Design of the Adjustable Parameter ECG Signal Generator Based on DSP and MCU,TP368.12
  4. Distributed Optical Fiber Sensor Technology and Utilizations in Smart Grid,TP212.14
  5. Based on DSP and CPLD design and implementation of motion control card,TP273
  6. Permanent magnet linear motor Magnetic Levitation System Control Strategy,TM359.4
  7. Development of the Control and Processing System for Currency Sorter,TH693.5
  8. Research on the DSP Based Sensorless PMSM Control System,TM341
  9. Mach - Zehnder distributed optical fiber vibration sensor system research,TP212.14
  10. DSP-based signal detection system implementation logging,TP274.4
  11. Design and implementation of CANopen protocol,TP273
  12. Infrared spectrometer arm Control System,TP273
  13. The Research on High-speed Low-power Signal Sampling System Based on DSP and USB2.0,TP274.2
  14. AIS Marine Radio Test Platform Testing Software Design,TP274
  15. Research on the Embedded Fiber Sensing System Based on DSP,TP212.14
  16. Design of Miniature Wireless Neural Recording System,TP274.2
  17. DSP-based research and development of STATCOM,TM761
  18. The Applications of Fiber Sensors in the Measurement of Seawater Salinity,TP274
  19. F2812 DSP -based support system maglev combination of digital controller,TH133.3
  20. Design and Realization of Micro Navigation System Based on Floating-Point DSP,V249.322
  21. DSP-based variant wing SMA actuator control system,V224

CLC: > Mathematical sciences and chemical > Physics > Optics > Nonlinear optical ( light and matter) > Stimulated Brillouin scattering
© 2012 www.DissertationTopic.Net  Mobile