Research And Implement Of Tunable Optic Time Domain Reflectometry

With the development and widespread use of optical communication technique, the technique of optical network has already evolved into DWDM-PON (Dense Wavelength Division Multiplexing Passive Optical Network) instead of present TDM-PON (Time-Division Multiplexing Passive Optical Network) step by step. As an indispensable and important instrument for optical fiber network measurement, Optic Time Domain Reflectometry(OTDR) has continuously improved following the development of optical network. Nowadays the method of traditional optical time domain reflecting is using a single wavelength light source to detect optical network, but OTDR with single wavelength can’t accomplish the detecting task of DWDM-PON which is faced to by the reflectometry.Towards the application requirements, this paper makes a study of wavelength Tunable OTDR from both the theory and practice. The paper is written for scientific research item based on Tunable OTDR and the author has finished system plan and produced partial objects. Through the analysis of theory and Realize points towards Tunable OTDR, we determined the system design proposal of Tunable OTDR based on AMR+FPGA. It completes the system hardware design, FPGA sequential logic design, ARM-Linux software design. The hardware design section includes the production of tunable light source optical signal amplification, the A/D sampling circuit, the FPGA subsystem hardware circuit design. FPGA sequential logic design section which includes the equivalent sampling logic, real-time sampling logic, and data storage handling logic is completed. In ARM software system design section, we finish the transplantation of an embedded Linux operating system, the overall design of Tunable OTDR software, and OTDR event analysis algorithm. Finally it realizes the target of the Tunable OTDR research and implement.