An dynamic optical filter 10 is provided to selectively attenuate or filter a wavelength band(s) of light (i.e., optical channel(s)) or a group(s) of wavelength bands of an optical WDM input signal 12. The optical filter is controllable or programmable to selectively provide a desired filter function....http://www.google.com.tw/patents/US20020176151?utm_source=gb-gplus-share專利 US20020176151 - Dynamic optical filter having a spatial light modulator
