| 摘要 |
An optical flattening filter is cascaded with an optical filter between an input and an output of an optical arrangement to provide a substantially widened flat passband at an output of the optical arrangement. The optical filter is responsive to an input signal for generating a periodic or a periodic output response waveform having a cosine squared or Gaussian passband or any rounded passband shape. The optical flattening filter is designed to generate a response waveform having a spectral profile which is complementary to the periodic or aperiodic output response waveform of the optical filter. The interaction of the response waveforms of the optical filter and the optical flattening filter provide a resultant response waveform at the output of the optical arrangement wherein each peak therein is substantially flattened to provide a passband which is wider than the response waveform provided by the optical filter. |
