Method and system for detection of regions of instability in multi-section tunable lasers

A method of obtaining a measurement plane from a multi-section tunable laser, the method comprising:

• (a) obtaining a first set of measurement values for the output of the laser diode by increasing a first control current through a range of values in a positive direction and decreasing a second control current in a negative direction at the same time;
• (b) increasing one of the first or second control currents by a step;
• (c) obtaining a second set of measurement values for the output of the laser diode by increasing the second control current through a range of values in a positive direction and decreasing a first control current in a negative direction at the same time;
• and
• (d) repeating steps (a)-(c) until a sufficient range of the first and the second control current has been used, wherein total control currents to the laser are changing at a continuous rate.

A control system for obtaining a measurement plane from a multi-section tunable laser diode, the control system comprising:

• means for obtaining a first set of measurement values for an output of the laser diode by increasing a first current through a range of values in a positive direction;
• means for increasing a second control current by a step after obtaining the first set of measurement values;
• means for obtaining a second set of measurement values for the output of the laser diode by decreasing the first control current through a range of values in a negative direction;
• means for increasing the second control current by a step after obtaining the second set of measurement values;
• means for operating the foregoing means elements to repeatedly obtain first and second measurement values and to increase the second control current by a step until a sufficient range of the second control current has been used;
• and
• means for identifying, in a resultant data set, regions of hysteresis.

A control system for obtaining a measurement plane from a multi-section tunable laser diode, the control system comprising:

• means for obtaining a first set of measurement values for an output of the laser diode by increasing a first control current through a range of values in a positive direction and decreasing a second control current in a negative direction at the same time;
• means for increasing one of the first or second control current by a step after obtaining the first set of measurements;
• means for obtaining a second set of measurement values for the output of the laser diode by increasing the second control current through a range of values in a positive direction and decreasing a first control current in a negative direction at the same time;
• and
• means for operating the foregoing means elements to repeatedly obtain first and second sets of measurements and to increase one of the first or second control current by a step until a sufficient range of the first or second control current has been used, where total control currents to the laser are changing at a continuous rate.

A control system for obtaining a measurement plane from a multi-section tunable laser diode, the control system comprising:

• a current source control for obtaining a first set of measurement values for an output of the laser diode by increasing a first control current through a range of values in a positive direction;
• a meter for obtaining a second set of measurement values for the output of the laser diode by decreasing the first control current through a range of values in a negative direction;
• an increment function for increasing a second control current by a step after obtaining the first set of measurement values but before obtaining the second set of measurement values, and for incrementing the second control current by a step after obtaining the second set of measurement values;
• a repetition function for repeatedly obtaining first and second measurement values and incrementing the second control current over a predetermining range of possible values for the second control current;
• and
• a computing apparatus for identifying regions of hysteresis in a resultant data set.

A control system for obtaining a measurement plane from a multi-section tunable laser diode is provided, the control system comprising:

• a current source control for obtaining a first set of measurement values for an output of the laser diode by increasing a first control current through a range of values in a positive direction and decreasing a second control current in a negative direction at the same time;
• a meter for obtaining a second set of measurement values for the output of the laser diode by increasing the second control current through a range of values in a positive direction and decreasing a first control current in a negative direction at the same time;
• a increment control for incrementing either the first control current or the second control current by a step after obtaining the first set of measurement values but before obtaining the second set of measurement values;
• and
• a repetition control for repeatedly obtaining first and second sets of measurement values, and incrementing the first or second control current, over a predetermined range of the first and second control currents, wherein the total control currents to the laser are changing at a continuous rate.