The function of a laser driver is to deliver the exact amount of current set, and at whatever voltage is needed, to the laser diode in a circuit. As a result, they protect the laser diode from damage.
Laser driver applications
Laser drivers are used in a variety of applications, from diagnostic and analytical equipment in the medical field to welding.
Why does a diode need a laser current driver?
An often overlooked factor in using laser diodes in circuits is the influence of temperature on the output power and operating current.
While the threshold current rises as the temperature increases, the optical output power and differential efficiency decrease. The driver circuit therefore needs a safety feature that ensures that a significant temperature increase will not destroy the laser – a laser driver fulfils this need.
Laser drivers provide closed-loop control of the average optical power of a continuous wave (CW) laser diode. The control loop adjusts the laser to maintain a constant current and power. This ensures a regular temperature and so protects the laser from heat damage.