Laser Diode Drivers

Driver circuits for laser diodes are either automatic power control (APC) circuits that maintain a constant light output power or automatic current control (ACC) circuits that maintain a constant current. The output power and wavelength of the laser diode can be affected by the changing of temperature. APC circuits provide a constant light output power despite variations in ambient temperature. If you have a DC power supply which provides you an accurate and stable DC voltage. You may use this APC circuit board without voltage regulator. APC with voltage regulator circuit enhances the function of APC circuit. It provides constant output power when the input voltage is between 2.8V DC and 6V DC.

Even with constant current drive, the output power of laser diodes varies with ambient temperature. However, a slight change of output power during operation is acceptable for many applications such as laser pointer and laser sight. In addition, battery is the most popular power source for laser diode module. In this case, the output power of laser will go down caused by the battery voltage decreased. The ACC circuit will provide the laser diode with constant current and stable output power.