Optical frequency filter

An optical frequency filter comprising:

• a frequency dependent disperser that disperses a frequency modulated input optical signal to form a dispersed signal having a plurality of frequencies;
• an attenuator that modulates at least one of the dispersed plurality of frequencies;
• and
• a frequency dependent combiner that combines the frequencies in the dispersed signal to generate an intensity modulated output signal, the output signal having a transmitted power of light through the frequency filter that is a monotonically varying function with respect to frequency over a selected bandwidth.

In an optical communications network, a frequency modulation (FM) to intensity modulation (IM) converter comprising:

• a frequency dependent disperser that disperses a frequency modulated light signal into a plurality of frequencies;
• a modulator that modulates at least one of the plurality of frequencies to generate a spatially mapped, dispersed signal;
• and
• a frequency dependent combiner that combines the frequencies in the dispersed signal to form an intensity modulated output signal, the output signal being transmitted through the converter comprising a monotonically varying function with respect to frequency over a selected bandwidth.

An optical communication system comprising:

• an optical FM source operating in communication with a transmitter, the source being further capable of outputting a FM optical signal;
• an optical transmission link for carrying the FM optical signal to a receiver;
• a FM to IM converter in communication with the receiver, the converter including a frequency dependent disperser to disperse light associated with the FM optical signal such that a plurality of frequencies are coupled to a modulator that modulates an intensity of one or more frequencies to generate a spatially mapped, dispersed signal and a frequency dependent combiner to produce an IM output signal that is linear with frequency over a selected bandwidth;
• and
• a detector to detect IM signals.

A method to convert input FM optical signals to IM optical output signals, comprising the steps of:

• dispersing an FM input optical signal using a frequency dependent disperser to form a dispersed optical signal having a plurality of frequencies;
• modulating the dispersed optical signal using a modulator that spatially maps and alters a magnitude of one of the plurality of frequencies;
• and
• combining the dispersed optical signal using a frequency dependent combiner to form an intensity modulated output signal, the intensity modulated output signal comprising a monotonically varying function with respect to frequency over a selected bandwidth.

A method of filtering a received optical signal comprising the steps of:

• dispersing a frequency modulated input optical signal using a frequency dependent disperser to form a dispersed optical signal having a plurality of frequencies;
• modulating the dispersed optical signal using a modulator that modulates one of the plurality of frequencies using spatial mapping;
• and
• combining the optical signal using a frequency dependent combiner to form an IM output signal that monotonically varies with frequency over a selected bandwidth.

A method of filtering a received optical signal comprising the steps of:

• forming a plurality of filters in series or parallel, each filter having a disperser, an attenuator and a combiner and comprising the steps of:
• dispersing a frequency modulated input optical signal using a frequency dependent disperser to generate a dispersed optical signal having a plurality of frequencies;
• modulating the dispersed optical signal using a spatial mapping modulator that modulates one of the plurality of frequencies;
• and
• combining the optical signal using a frequency dependent combiner to generate an intensity modulated output signal that monotonically varies with frequency over a selected bandwidth.

A method to shape the transmission of a an optical signal with respect to frequency comprising the steps of:

• dispersing a frequency modulated input optical signal using a frequency dependent disperser to form a dispersed optical signal having a plurality of frequencies;
• modulating the dispersed optical signal using a modulator that modulates at least one of the plurality of frequencies to generate a spatially mapped, dispersed signal;
• and
• combining the dispersed optical signal using a frequency dependent combiner to form an intensity modulated output signal that is linear with frequency over a selected bandwidth.