A variable optical source 801 to selectively provide a desired optical output signal in response to a control signal is provided. The optical source includes an optical filter that attenuates a broadband optical input signal or a multi-spectral input signal 802. The optical filter is controllable or...http://www.google.com.hk/patents/US20020176149?utm_source=gb-gplus-share專利 US20020176149 - Variable optical source
