Laser driver pulse shaping control
AssigneeAnalog Devices International Unlimited Company
InventorsJonathan Ephraim David Hurwitz, Davide Portaluppi
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Abstract
Time-of-flight (ToF) systems which use pulsed laser diodes, are required to measure distances with high level of precision and control. The present disclosure provides a method and a corresponding system for controlling a temporal response of a laser diode, in particular pulsed laser diodes. In particular, the present disclosure provides a method and a related system for driving a laser diode so as to obtain predominantly a peak pulse response while minimising or completely avoiding the post-peak response in a temporal response of the laser diode.
Claims20
A method of determining a duration, Tdr, for a laser drive signal, to minimise post-peak response in a temporal response of a laser diode driven by the laser drive signal, the method comprising:
- iteratively:
- applying a test drive signal having a test duration, Tt, to the laser diode;
- monitoring an output of a photodetector, wherein the output is indicative of an energy of a light pulse output by the laser diode in response to application of the test drive signal;
- varying the test duration, Tt, of the test drive signal with successive iterations;
- and
- determining a temporal response output characteristic of the laser diode with successive iterations;
- and
- then, in response to the temporal response output characteristic of the laser diode meeting at least one criterion for at least one of the successive iterations, setting the duration, Tdr, based on the test duration Tt.
A control unit for determining a duration, Tdr, for a laser drive signal, to minimise post-peak power in a temporal response of a laser diode driven by the laser drive signal, and comprising an input for coupling to an output of a photodetector, and an output for coupling to an input of the laser diode, wherein the control unit is configured to:
- iteratively:
- apply a test drive signal having a test duration, Tt, to the laser diode;
- monitor an output of the photodetector, wherein the output is indicative of an energy of a light pulse output by the laser diode in response to application of the test drive signal;
- vary the test duration, Tt, of the test drive signal with successive iterations;
- and
- determining a temporal response output characteristic of the laser diode with successive iterations;
- and
- then, in response to the temporal response output characteristic of the laser diode meeting at least one criterion for at least one of the successive iterations. setting the duration, Tdr, based on the test duration Tt.
A system for determining a duration, Tdr, for a laser drive signal, to minimise post-peak response in a temporal response of a laser diode driven by the laser drive signal, the system comprising:
- a laser diode;
- a photodetector;
- a control unit to the laser diode and the photodetector, wherein the control unit is configured to:
- iteratively:
- apply a test drive signal having a test duration, Tt, to the laser diode;
- monitor an output of a photodetector, wherein the output is indicative of an energy of a light pulse output by the laser diode in response to application of the test drive signal;
- vary the test duration, Tt, of the test drive signal with successive iterations;
- and
- determining a temporal response output characteristic of the laser diode with successive iterations;
- and
- then, in response to the temporal response output characteristic of the laser diode meeting at least one criterion for at least one of the successive iterations, setting the duration, Tdr, based on the test duration Tt.
Dependencies are inferred from the claim text.