Band-pass filter e.g. for optical data signal in wavelength multiplexed transmission system, has transmission curve with attenuation region including center frequency

摘要

A band-pass filter for optical data signals whose transmission characteristic (T) has a pass-zone at a center frequency (F0) for bandwidth (delta f). The transmission characteristic (T) has an attenuation zone which includes the center-frequency (F0). Independent claims are included for (a) a filter arrangement with several band-pass filters and (b) for a method of increasing the sensitivity of receiving optical data signals.