| 摘要 |
The invention proposes a Grouped Optical Add Drop Multiplexer (GOADM -100, 80) comprising a periodic filter (62, 72, 102, 86, 90) for forming a group of spaced optical wavelengths to be dropped or added. The GOADM is also provided with one or more secondary filters (68, 78, 112, 114, 88, 92) connected to the periodic filter serving a primary filter, wherein each of the secondary filters is responsible of dropping or adding one particular wavelength from the group. |
