哪位高人帮我翻译一下摘要？

As the all-optical signal transmission network for all the light within, no longer have power relay, so all-optical network has the transparency of the signal, the network structure of scalability, reconfigurability, operability, and many other advantages. And end-users as to achieve all-optical network connections, which will deploy between the circuit and switching more simple and convenient. From the development trend, the establishment of a true to WDM technology and optical switching technology based on optical network layer, into pure "all-optical network," Elimination of optical / electrical conversion bottlenecks in the development of optical communication has become an inevitable trend.
At present people are all-fiber wavelength division multiplexing devices, little research, the current can be put to practical use and mass production of the device also only two channels. Multi-channel all-optical wavelength division multiplexer has been suggested, but due to the actual production of the device can not accurately control the splitting ratio, so not yet in use. Paper focuses on the existing channel all-fiber wavelength division multiplexer and producing less light than the issue of hours of study to improve.
In this paper, multi-level WDM devices in series method proposed three new all-fiber-based multi-channel wavelength division multiplexer structure, namely:
(1) Based on 2 × 2,2 × 2 and 3 × 3 coupler cascaded Mach - Zehnder interferometer (MZI) structure.
The wavelength division multiplexer structure is Professor Di Zai LU Huai-wei, "All-fiber wavelength interleaving filter" and improved on the basis made of it to improve the original filter is only two channels of Zhuangkuang, to achieve a good three-channel wave division multiplexing, the output light can reach flattened effect, simple structure, easy to produce, basically solved the splitting ratio of the production process control problem.
(2) based on 2 × 2,3 × 3 and 3 × 3 coupler cascaded MZI structure.
The WDM device structure is proposed first WDM based on the structure, which topped out in the output light of the effects of the effects in the most ideal, but there is always a weaker light output channel. Also in the production of basically solve the problem of the splitting ratio control, a certain degree of practicality.
(3) based on 3 × 3,3 × 3 and 3 × 3 coupler cascaded MZI structure.
The third WDM structure based on the previous two, although it is relatively flat top effect of the effect of the ideal, but somewhat complicated structure, there are still hours of light produced can not be accurately than control problems, practical not very strong.