Thermal chirp compensation systems for a chirp managed directly modulated laser (CML™) data Link

A fiber optic communication system for receiving an electronic digital data signal and transmitting the same, comprising:

• an optical signal source adapted to receive the digital data signal and to produce a frequency modulated optical signal from a directly modulated semiconductor laser;
• and
• an optical spectrum reshaper adapted to convert the frequency modulated optical signal into an amplitude modulated optical signal;
• wherein the semiconductor laser is configured so that the adiabatic chirp per unit of modulating current exceeds the thermal chirp per unit of modulating current over an operative range of frequencies.

A fiber optic communication system for receiving an electronic digital data signal and transmitting the same, comprising:

• an optical signal source adapted to receive the digital data signal and to produce a frequency modulated optical signal from a directly modulated semiconductor laser;
• an optical spectrum reshaper adapted to convert the frequency modulated optical signal into an amplitude modulated optical signal;
• and
• an electronic circuit adapted to modify the electronic digital data signal so as to additionally modulate the frequency modulated optical signal whereby to reduce the variations in the amplitude of the 1 and 0 logic levels in the amplitude modulated optical signal.

A fiber optic communication system for receiving an electronic digital data signal and transmitting the same, comprising:

• an optical signal source adapted to receive the digital data signal and to produce a frequency modulated optical signal from a directly modulated semiconductor laser;
• an optical spectrum reshaper adapted to convert the frequency modulated optical signal into an amplitude modulated optical signal;
• and
• an electronic circuit to modify the electronic digital data signal to additionally modulate the optical source, wherein the electronic circuit is adapted to compensate for the thermally induced frequency variations of the optical signal source.

A method for transmitting an electronic digital data signal through a fiber optic communication system, comprising:

• modulating an optical signal source with a digital data signal so as to produce a frequency modulated optical signal from a directly modulated semiconductor laser;
• converting the frequency modulated optical signal into an amplitude modulated optical signal with an optical spectrum reshaper;
• and
• compensating for the adverse effects of the thermal chirp normally induced in the frequency modulated optical signal by modulating the semiconductor laser with the electronic digital data signal.