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31.
Michel Joindot 《电信纪事》2003,58(11-12):1725-1756
After briefly recalling the recent history of optical communication, this paper describes the structure of aWDM system, the critical parameters involved in its design, the different degradations which the transmitted signal suffers from, the state of the art and the future evolutions ofWDM transmission technology. Some recent results are given to illustrate the best results obtained in the research laboratories. 相似文献
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Measurements are reported of intervalence band absorption (IVBA) coefficient k/sub 0/ in three types of active layer structure: bulk, unstrained (MQW) and strained multiquantum wells. The IVBA measurements are performed by observing the spontaneous emission from the uncleaved facets of DCPBH Fabry-Perot lasers. k/sub 0/=(3.7+or-0.3)*10/sup -17/ cm/sup 2/ is obtained for bulk, (1.4+or-0.2)*10/sup -16/ cm/sup 2/ for MQW unstrained and (3.5+or-0.3)*10/sup -17/ cm/sup 2/ for strained MQW structures.<> 相似文献
34.
Michel Joindot 《电信纪事》1976,31(9-10):281-290
The knowledge of the coupling coefficients in a slightly non cylindrical waveguide is very important because it is the first step in the calculation of the additional attenuation of TE 01 mode due to the perturbation. In practice, it is quite impossible to get a perfectly cylindrical waveguide because of the limits of mechanical accuracy in the manufacturing process. A calculation method of the coupling coefficients is given in this paper and it leads to expression which have been already published, but using a different method. Ideal metallic waveguide, lined waveguide and helix waveguide are considered : in the third case it is shown that the method gives a quite general expression, which can be reduced in a simplified one, already published, in the particular case of the TE 01 mode. 相似文献