Method and circuit arrangement for correcting the light power output of a laser diode

A method for correcting light power of a laser diode, comprising the steps of:

• providing a constant current source to provide driver current for driving the laser diode;
• modulating the constant current source with a modulating signal at a modulating input thereof;
• with a low-pass filter having said modulating signal at its input, creating a correction signal at an output of the low-pass filter which simulates a chronological thermal behavior of laser transition dependent on the modulating signal;
• enhancing the correction signal to create a re-correction signal which more exactly matches non-linear thermal behavior of said laser transition;
• and
• feeding said re-correction signal to said constant current source to correct the light power of the laser diode.

A circuit arrangement for correcting an output light power P of a laser diode, comprising:

• generator means connected to said laser diode for generating a driver current I.sub.T which defines said output light power P;
• means for modulating said driver current I.sub.T dependent on a modulation signal;
• a low-pass filter means for receovomg said modulation signal for approximately simulating a chronological curve of an internal temperature of said laser diode dependent on said modulation signal, and for providing a correction signal for correction of said driver current I.sub.T in order to compensate a dependency of said output light power P on said internal temperature of said laser diode;
• and
• a function generator means for enhancing compensation precision by providing a re-correction function which re-corrects said correction signal of said low-pass filter and outputs a re-correction signal according to said re-correction function, an input of said function generator means being connected to an output of said low-pass filter means, an output thereof being connected to a control input of said generator means for converting said driver current I.sub.T into a corrected driver current I.sub.T * for the laser diode.

A circuit arrangement for correcting light power P of a laser diode, comprising:

• first generator means connected to said laser diode for generating a driver current I.sub.T for said laser diode which defines said output light power P;
• means for modulating said driver current I.sub.T dependent on a modulation signal;
• a low-pass filter means input with said modulation signal for approximately simulating a chronological curve of an internal temperature of said laser diode dependent on said modulation signal;
• said low-pass filter means creating a cprrectopm signal for correction of said driver current I.sub.T to compensate a dependency of said output light power P on said internal temperature of said laser diode;
• second generator means connected to said laser diode for generating a correction current I.sub.K for said driver current I.sub.T ;
• and
• function generator means for providing a re-correction signal based on a re-correction function for enhancing compensation precision, an input of said function generator means being connected to receive said correction signal output from said low-pass filter means and an output of said function generator means being connected to a control input of said second generator means in order to modify said correction current I.sub.K with said correction signal.

A circuit arrangement for correcting light power P of a laser diode, comprising:

• first generator means connected to said laser diode for generating a driver current I.sub.T for said laser diode for defining said output light power P;
• means for modulating said driver current I.sub.T dependent on a modulation signal;
• a low-pass filter means which receives said modulation signal for approximately simulating a chronological curve of an internal temperature of said laser diode dependent on said modulation signal, said low-pass filter means providing a correction signal for correction of said driver current I.sub.t for compensating a dependency of said output light power P on said internal temperature of said laser diode;
• a second generator means connected to said laser diode for generating a correction current I.sub.K for said driver current I.sub.T ;
• a third generator means for generating a bias current I.sub.B for said laser diode, an output of said third generator means being connected to said laser diode and a control input thereof being connected with a first control signal;
• switch means between said laser diode and said output of said third generator means for being actuated by a third control signal;
• a first multiplier means connected to receive a second control signal and said modulation signal, said second control signal being connected to a control input of said first generator means;
• a second multiplier means connected to receive said first control signal and said third control signal;
• adder means whose inputs are connected to outputs of said first and second multiplier means and whose output is connected to an input of said low-pass filter means;
• and
• a function generator means for providing a re-correction signal based on a recorrection function for correcting the correction signal of said low-pass filter means for enhancing compensation precision, an input of said function generator means being connected to said correction signal from said low-pass filter means and an output of said function generator means being connected to a control input of said second generator means.