Current spike reduction technique for high power laser diode driver with pulse current output

A Vertical-Cavity Surface-Emitting Laser (VCSEL) has attracted a strong interest as a pump source of diode pumped solid state (DPSS) lasers for many applications, such as welding, cutting and marking, in recent years. In the past, a series dropper has been typically used as a laser driver. However, the power loss of series dropper which adopts several kW class high power laser is very large, and the cooling system becomes much larger and whole driver is also much larger. In order to solve these problems, switch mode power supply (SMPS) is adopted as a laser driver. However, switch device breakdown problem occurs in this case. This paper clarifies the mechanism of mentioned above problem and proposes the solution technique.