The Research Of Optical Performance Monitor

During the past decade, optical transport has enabled the rapid growth of data traffic in the network backbone. Further increases in capacity are gained by moving to dense wavelength division multiplexing (DWDM) with large channel counts. Optical performance monitor (OPM) is essential for managing such high capacity optical transmission and switching systems, Ultralong haul and optically swithed networks, with new optical layer functionality such as dynamic reconfiguration and link level restoration, promise improved operations, reduced footprint and cost. However, these benefits come with the added complications required by managing transparent networks and have stimulated interest in OPM for enhanced fault management applications. All of these issues bring focus to OPM as an enabling technology for next generation optical networks.At present, OPM is mostly developed by the technology of optical dispersion, such as optical adjustable filter, optical wavelength division implement. By the technology of optical wavelength division implement, OPM can't distinguish the excursion of center wavelength and the factor of permance change among optical power, because the characteristic of spectral filter is fixed. By the techenology of optical adjustable filter, it can scan frequency spectral of multiple wavlength of DWDM and analyze data, work out optical power value and OSNR fastly. But now the technology of optical adjustable filter isn't perfect enough and costs much. So the technology of OPM must improve.This thesis is based upon "Intelligentize Optical Performance Monitor". Its' optical system applies MEMS Scanner. Scanner turning different angle can refract different wavelength of optical signal. Then through photoelectricity transform, A/D transform, data acquisition and signal processing, it can work out optical power, center wavelength and OSNR of every channel, then deduce many parameters such as wavelength excursion, ASE, gain and gain decline of amplifier, Q value and so on. Through these parameters, OPM can available detect every channel.The main task including are as follows:(1) The design of OPM circuit. It mainly includes photoelectricity transform and amplifier circuit, A/D transform and data acquisition circuit.(2) The algorithm of spectral signal processing is researched. FFT and WaveletTransform are introduced and compared, and Wavelet Transform is selected finally. The idea of LabVIEW and Matlab mix programme is used. (3) The design of OPM software. It is finished by LabVIEW.