Optical Channel Fault Monitoring Techniques Using Fabry-Perot Laser Diodes

• Main Authors: Yi-Tsuen Hu, 胡懿存
• Other Authors: Chun-Liang Yang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/42347507034588211226

碩士 === 淡江大學 === 電機工程學系碩士班 === 98 === With the upcoming era of broadband applications, the users are going to demand far more bandwidth. Fiber-optic network has become the best solution in wired broadband networks. Among the existing access network technologies, passive optical network (PON) is predominant. It can provide high quality and ultra-wideband transmission network services, but it only needs some passive optical components placed in the region between the central office and end users. Thus construction and maintenance issues derived from the exposure of active optical components in the outdoor environment can be avoided. Therefore, passive optical network architecture can simultaneously meet the requirements for simplifying network design and reducing the cost of deployment and maintenance. In order to ensure the quality of network service, how to effectively maintain the passive optical network system is indeed very important as an issue. In this thesis, we propose a fault monitoring system, which can detect the breaking of distribution fibers and monitor the statuses of optical network units (ONUs) in passive optical networks. This fault monitoring system adopts the operation in polling mode. An optical monitoring unit (OMU) at an ONU, which employs a Fabry-Perot (FP) laser diode as an optical transceiver, normally operates in receiving state. When an OMU receives its identity frequency, FP laser diode will be turned into transmitting state and then be modulated by a corresponding tone according to the status of an ONU. Under the circumstances, the tone decoder at the optical line terminal can decode the statuses of each distribution fiber and ONU.