Research on Power Stability Control Technology of Light Source for Steel Ball Surface Defect Detection

When the semiconductor laser is used as the light source device to detect the surface defects of steel balls, because its output light power and light wavelength are greatly affected by injection current, ambient temperature and other factors, the output power of the light source is unstable, which will seriously affect the accuracy of steel ball surface defect detection. To solve this problem, this paper designs a power stability control system of small power semiconductor laser based on single-chip microcomputer, which can feedback control the output power and working temperature of the laser, and add an optical isolator in the laser to achieve automatic control of laser luminous power stability. After the simulation of the system, the 1310nm and 1550nm lasers are tested experimentally. The test results show that the circuit works reliably and the optical power control effect is good. The instability of the output power of the two lasers is 1.42% and 1.7% respectively. This design provides a relatively stable light source for the detection of steel ball surface defects.