| 摘要 |
A tuneable filter arrangement (10) includes a plurality of tuneable Bragg gratings (22, 24), each grating (22, 24) arranged, in use, to be independently tuneable to different wavelengths, a first switch (16) for selectively directing an incoming optical signal (26) to any one of the gratings (22, 24), a first optical element (18) arranged, in use, such that an optical signal transmitted through any one of the gratings (22, 24) is directable to a through-output of the filter arrangement (10), and an optical drop structure (20) arranged, in use, such that a filtered optical signal from any one of the gratings (22, 24) is dropped at a drop-output (28) of the filter arrangement (10). The first switch (16) and the first optical element (18) maybe Y junction thermo-optic switches, and the optical drop structure (20) may be an optical circulator. Another optical circulator may be provided at the through-output of the filter arrangement (10) for adding WDM channels to the through-output signal. |
