| 摘要 |
<p>First 2, 3 and second 5, 6 pairs of signals 7 the signals of each pair being at a different frequency, are input to first and second wavelength division multiplexers 4, 7 to provide corresponding multiplexed signals 8, 10 of orthogonal polarizations. Polarising beam splitter 9 receives both multiplexed signals and passes them 11 to quarter waveplate 12. The resultant circularly polarized signal passes via the rotatable joint 1 to a second quarter waveplate 13 and thence 14 to a second polarising beam splitter 15, and then 16, 18 to third and fourth wavelength division multiplexers 17, 19. This enables the four input signals to be output 20, 21, 22, 23. <IMAGE></p> |
