摘要 |
<p>Wavelength-multiplexed light including wavelength lights (»1, »2, ···, »n) is separated at periodic intervals of wavelength by means of a periodic optical filter (1), thereby generating wavelength groups composed of the following wavelength lights (»1, »p+1, »2p+1, ···), (»2, »p+2, »2p+2, ···), ···. Then, an optical switching section (3) selects any one of the wavelength groups and introduces the selected wavelength group into a periodic optical filter (2). Making the period p of the periodic optical filter (1) different from the period q of the periodic optical filter (2) causes the wavelength lights included in each wavelength group to be outputted at the different separation ports of the periodic optical filter (2). As a result, each wavelength light is separated completely from the other wavelength lights.</p> |