Research On High Accuracy And Wide Dynamic Range Optical Power Meter

With the rapid development of modern fiber-optic communication technologies, asone of the basic fiber-optic test equipments, the existing domestic optical power metershave been increasingly unable to meet the system testing requirements of high accuracyand long distance. There is an urgent need to launch more excellent performance opticalpower meters for the markets. In consideration of the high price of the foreign products, itis necessary to research and develop the high performance optical power meter to meet thedomestic demands, and break the monopoly of foreign technology.At present, domestic optical power meters have following problems: the measurementrange (-70to10dBm) is narrow, the accuracy of measurement (0.2dB) is low, and the testspeed (about100ms) is slow. Based on the study of the photoelectric detection technology,this paper presents a design scheme of high accuracy and wide dynamic range opticalpower meter, by establishing and simulating the models of photoelectric conversion, signalamplification, the noise suppression of the signal chain. It is mainly used for low opticalpower detection to extend the measurement range (-90to10dBm), while improving theaveraging time to125us and accuracy up to0.005dB, and can be used as the digital opticalpower meter for the transient testing, which meets the requirements of measurementaccuracy, response speed and measurement range in the high speed and long distanceoptical communication systems.On the basis of investigating the structures and working principle of the optical powermeter, firstly, this paper introduces several common photoelectric detectors used inphotoelectric detection systems, including their working principle, structures, equivalentcircuit models and characteristic parameters. Secondly, this paper analyzes thephotoelectric detection circuits and the models of the preamplifier circuits, and estimatesthe noise of the photoelectric detection circuits. Thirdly, this paper discusses the designscheme and ideas of the high accuracy and wide dynamic range optical power meter indetail. At last, based on the testing of the optical power meter and the analyses of experimental datas, it shows that the design scheme of high accuracy and wide dynamicrange optical power meter has achieved the desired objectives at the aspects of accuracy,speed and range, verifies that the design scheme is feasible.