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光纤传感网络是一种重要的传感网络。将国内外现有光纤气体传感器网络的多址技术归纳为:频分多址、时分多址、波分多址和码分多址等四类。前两类受铌酸锂调制器的消光比及偏振相关性能的制约,且存在无法多点同时监测、系统损耗较大等缺陷。采用波分多址技术的网络,其损耗及监测点间串扰均较小,但受到待测气体吸收峰位置和强度等因素制约,且成本较高。采用光码分多址技术的传感网络,可同时检测位置与浓度信息。该网络采用环行器代替耦合器降低损耗,还可利用全光缓存技术数十倍增加气室有效长度。此类网络将成为气体传感网络发展的重要方向之一。
Optical fiber sensing network is an important sensing network. At home and abroad existing multi-access optical fiber gas sensor technology summarized as: frequency division multiple access, time division multiple access, wavelength division multiple access and code division multiple access four categories. The first two types are affected by the extinction ratio and the polarization-dependent performance of the lithium niobate modulators, and there are some defects that they can not be monitored at the same time and have large system losses. WCDMA networks, the loss and crosstalk between monitoring points are small, but by the gas absorption peak position and strength constraints and other factors, and the higher the cost. Sensing network using optical code division multiple access technology, can detect position and concentration information. The network uses a circulator instead of a coupler to reduce the loss, and can also use the all-optical buffer technology to increase the effective length of the gas chamber several times. Such networks will become one of the important directions for the development of gas sensor networks.