Calibrating a frequency difference between two or more lasers over an extended frequency range

A method for calibrating a frequency difference between two or more lasers over an extended frequency range, comprising:

• measuring, with a frequency detector, a first value of a frequency difference between a signal from a first laser and a signal from a second laser, wherein the first frequency difference value lies within a finite range of the frequency detector;
• fixing a parameter of the first laser to fix a frequency of the first laser;
• varying a parameter of the second laser to vary a frequency of the second laser;
• for one or more values of the second laser parameter, measuring, with the frequency detector, a second value of the frequency difference between the signal from the first laser and the signal from the second laser, wherein a frequency difference range between the first and second frequency difference values lies within the finite range of the frequency detector;
• fixing the second laser parameter to fix the frequency of the second laser;
• varying the first laser parameter to vary the frequency of the first laser;
• and
• for one or more values of the first laser parameter, measuring, with the frequency detector, a third value of the frequency difference between the signal from the first laser and the signal from the second laser, wherein a frequency difference range between the second and third frequency difference values lies within the finite range of the frequency detector, and wherein a frequency difference range between the first and third frequency difference values extends beyond the finite range of the frequency detector.

A computer readable medium having embodied therein a set of computer readable instructions for implementing a method for calibrating two or more lasers over an extended frequency range, the method computer readable instructions comprising:

• a set of instructions for tuning the lasers in coordination with respect to one or more readily characterized narrow frequency ranges to characterize one or more tuning parameters of each of the lasers over the extended frequency range, wherein execution of the instructions on a computer generates signals that cause a detector to measure a frequency difference between the lasers and one or more tuning controllers to adjust one or more tuning parameters of the lasers in response to the signals,
• wherein the set of computer readable instructions for tuning the lasers in coordination includes:
• a set of instructions for calibrating the frequency difference with respect to the one or more tuning parameters over a first narrow frequency range;
• a set of instructions for calibrating the frequency difference with respect to the one or more tuning parameters over a second narrow frequency range;
• and
• a set of instructions for coordinating the resulting frequency difference calibrations for the first and second narrow frequency ranges to calibrate the frequency difference with respect to the one or more tuning parameters over the extended frequency range.

An apparatus for calibrating a frequency difference between a first laser and a second laser, the apparatus comprising:

• means for calibrating the frequency difference with respect to the one or more tuning parameters over a first narrow frequency range;
• means for calibrating the frequency difference with respect to the one or more tuning parameters over a second narrow frequency range;
• and
• means for coordinating the resulting frequency difference calibrations for the first and second narrow frequency ranges to calibrate the frequency difference with respect to the one or more tuning parameters over the extended frequency range.

An apparatus for calibrating a frequency difference between a first laser and a second laser, the apparatus comprising, comprising:

• a first tuning controller coupled to the first laser;
• a second tuning controller coupled to the second laser;
• an optical coupler optically coupled to the first laser and the second laser;
• a frequency detector coupled to the optical coupler;
• and
• a controller coupled to the frequency detector and the first and second tuning controllers, wherein the controller includes a processor and a memory, the memory containing a set of instructions that are executable by the processor, the set of instructions implementing a method far calibrating a frequency difference between the first and second lasers over an extended frequency range, wherein the tuning controllers and frequency detector are operable in response to signals from the controller, the instructions including a set of instructions directing the tuning controllers and frequency detector to calibrate a frequency difference between the first and second lasers with respect to the one or more tuning parameters of the first and/or second laser over a first narrow frequency range that is within a frequency range of the detector;
• a set of instructions directing the tuning controllers and frequency detector to calibrate a frequency difference between the first and second lasers with respect to the one or more tuning parameters over a second narrow frequency range that is within the frequency range of the detector and that is different from the first narrow frequency range;
• and
• a set of instructions for coordinating the resulting frequency difference calibrations for the first and second narrow frequency ranges to calibrate the frequency difference between the first and second lasers with respect to the one or more tuning parameters over an extended frequency range that is greater than the frequency range of the detector.

An optical signal generator apparatus, comprising:

• a first laser;
• a second laser;
• a first tuning controller coupled to the first laser;
• a second tuning controller coupled to the second laser;
• an optical coupler optically coupled to the first laser and the second laser;
• a frequency detector coupled to the optical coupler;
• and
• a controller coupled to the frequency detector and the first and second tuning controllers, wherein the controller includes a processor and a memory, the memory containing a set of instructions that are executable by the processor, the set of instructions implementing a method for calibrating a frequency difference between the first and second lasers over an extended frequency range, wherein the tuning controllers and frequency detector are operable in response to signals from the controller, the instructions including a set of instructions directing the tuning controllers and frequency detector to calibrate a frequency difference between the first and second lasers with respect to the one or more tuning parameters of the first and/or second laser over a first narrow frequency range that is within a frequency range of the detector;
• a set of instructions directing the tuning controllers and frequency detector to calibrate a frequency difference between the first and second lasers with respect to the one or more tuning parameters over a second narrow frequency range that is within the frequency range of the detector and that is different from the first narrow frequency range;
• and
• a set of instructions for coordinating the resulting frequency difference calibrations for the first and second narrow frequency ranges to calibrate the frequency difference between the first and second lasers with respect to the one or more tuning parameters over an extended frequency range that is greater than the frequency range of the detector.