Method and apparatus for optical frequency demodulation of an optical signal using interferometry

An optical frequency demodulator for selectively demodulating a first information stream from an input optical signal containing the first information stream and a second information stream, the input optical signal being characterized by frequency variations in a first frequency band which are representative of the first information stream and frequency variations in a second frequency band which are representative of the second information stream, the optical frequency demodulator comprising:

• a asymmetrical interferometer operable to introduce a plurality of interference ripples in the second frequency band of the input optical signal spectrum and discriminate the frequency variations in the first frequency band from the input optical signal to produce an intermediate optical signal;
• a photo-detector operable to convert the intermediate optical signal to an electrical signal representative of the first information stream;
• and
• a filter operable to filter the electrical signal to approximate the first information stream.

An optical frequency demodulator for selectively demodulating a first information stream from an input optical signal containing the first information stream and a second information stream, the input optical signal being characterized by frequency variations which are representative of the first information stream and intensity variations which are representative of the second information stream, the optical frequency demodulator comprising:

• a asymmetrical interferometer operable to discriminate the frequency variations in the input optical signal to produce an intermediate optical signal;
• a photo-detector operable to convert the intermediate optical signal to an electrical signal representative of the first information stream;
• and
• a filter operable to filter the electrical signal to approximate the first information stream.

An optical frequency demodulator for selectively demodulating a first information stream from an input optical signal containing the first information stream and second information stream, the input optical signal being characterized by frequency variations in a first frequency band which are representative of the first information stream and intensity variations in a second frequency band which are representative of the second information stream, the optical frequency demodulator comprising:

• interferometry means for discriminating the frequency variations in the first frequency band from the input optical signal to produce an intermediate optical signal;
• photo-detecting means for converting the intermediate optical signal to an electrical signal representative of the first information stream;
• and
• filtering means for filtering the electrical signal to approximate the first information stream.

An optical frequency demodulator for selectively demodulating a first information stream from an input optical signal containing the first information stream and a second information stream, the input optical signal being characterized by frequency variations in a first frequency band which are representative of the first information stream and frequency variations in a second frequency band which are representative of the second information stream, the optical frequency demodulator comprising:

• interferometry means for introducing a plurality of interference ripples in the second frequency band of the input optical signal spectrum and discriminate the frequency variations in the first frequency band from the input optical signal to produce an intermediate optical signal;
• photo-detecting means for converting the intermediate optical signal to an electrical signal representative of the first information stream;
• and
• filtering means for filtering the electrical signal to approximate the first information stream.