Specifically, a Laser Diode Power Supply (or Laser Diode Driver) is a very accurate DC source. The circuit consists of, among other things, a switching power supply, a (PID) regulator and an output filter. The important thing is: small ripple, little interference and high efficiency. Because the development of such circuits ties up a lot of resources, manufacturers of laser systems purchase OEM LDDs. This shortens the development time and brings the final product to market more quickly.