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Large capacity new progress on distributed optical fiber sensing network 2015.04.30
 With the rapid development of optical fiber network technology, optical fiber sensing network has become one of the research focus of the present optical fiber sensing technology to build large capacity, long distance, high precision. In recent years, time-division multiplexing, wavelength division multiplexing,frequency division multiplexing and multiplexing technology has been widely used in the quasi distributed optical fiber sensing technology in network. Traditional time division multiplexing technique in sensor networks often need to produce all kinds of signal pulse modulator, which greatly increased the cost ofsensor network. At the same time, the existing sensor network requires more manpower and resources for fault real-time monitoring of network survivability, which undoubtedly hinder the optical fiber sensing networkpractical applications in engineering.

The leadership of associate professor of Wuhan National Laboratory for optoelectronics, optical and electronic information, the research group designed a quasi distributed optical fiber sensor network of large capacity optical chaos and hybrid time based on WDM technology. In this design, the probe is no longer apulse of light, but noise generated by the SOA ring cavity of the continuous wide spectrum light signal,namely the wide spectrum of chaotic light. By using the hybrid TDM WDM technology, multiplexing sensingnetwork sensing unit of chirped fiber Prague grating has been greatly improved, the theoretical analysis can support 512 sensor nodes and access capability. The cross-correlation algorithm combining intensitydemodulation chirped Prague grating and chaotic light, measurement can realize quasi distributed optical fiber sensing parameters, but also the exact location of each sensor unit. At the same time, the sensor network has its own real-time optical fiber fault monitoring function, fault point measurement of high spatial resolution of 2.8 cm, which greatly enhance its unique advantages in engineering application of survivabilityand reliability.