Dynamic adjusting system for driving current of semiconductor laser pumping source

Abstract

The invention provides a dynamic adjusting system for driving current of a semiconductor laser pumping source. The dynamic adjusting system comprises a pumping source, an adjustable output voltage source, a current sampling resistor, an MOS tube and a dynamic current adjusting circuit, wherein the adjustable output voltage source is used for providing input voltage for the pumping source; the dynamic current adjusting circuit outputs MOS tube grid voltage corresponding to a preset pumping source current according to the preset pumping source current; real-time pumping source current is collected through the current sampling resistor; and the output voltage of the adjustable output voltage source is dynamically adjusted according to a deviation value between the preset pumping source current and the real-time pumping source current. According to a technical scheme provided by the invention, the output voltage of the adjustable output voltage source is adjusted in real time according to the change of each voltage and current parameter, the stable and reliable work of the pumping source is ensured, the abrupt change of the power consumption of the MOS tube is not caused when the rated current is switched, the heating power of the MOS tube is reduced, and the working stability of the whole system is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor lasers, in particular to a dynamic adjustment system for driving current of a semiconductor laser pumping source. Background technique [0002] Such as figure 1 Shown is the schematic diagram of the current constant current drive circuit of the existing semiconductor laser pump source. There may be one laser chip in a semiconductor laser pump source, or there may be multiple laser chips connected in series. The electrical performance of each laser chip is the same as that of a diode. The positive pole of the laser pump source is connected to the output positive pole of a DC constant voltage source, and its negative pole is connected to the drain of the constant current drive MOSFET. The source of the MOSFET is connected to a current sampling resistor, and the other end of the sampling resistor is connected to the above DC constant The negative pole of the piezoelectric power supply is the ...

AI Technical Summary

Problems solved by technology

[0008] The pumping source is composed of 30 laser chips in series, and its rated current is 20A. The voltage drop of each laser chip at the rated current is 1.7V; at the rated current, we make the MOSFET drain The voltage between the sources is the optimal value of 0.8V (too small to work in a constant current state, too large to cause high heat dissipation), and the resistance of the current sampling resistor is 0.05 ohms; then the preset constant voltage power supply voltage It is: V=30×1.7+0.8+20×0.05=51+0.8+1=52.8(V); at this time, the heating power consumption of MOSFET is: P=20×0.8=16(W); due to laser pumping Source constant current drive requires that the operating current range is continuously adjustable from 0 to the maximum current. Assume that the laser pump source is operated at a current of 10A. At this time, the voltage drop of each laser chip is 1.5, because the constant voltage power supply voltage has been preset. It is a fixed 52.8V, so according to formula (1), it can be concluded that the voltage between the drain and source of the MOSFET at this time is: Vmos=52.8–30×1.5–10×0.05=52.8–45–0.5=7.3 (V) ; At this time, the heat dissipation of MOSFET is: P=10×7.3=73(W), which will cause serious heat generation of MOSFET

Images