The Driver Circuit And High Precision Temperature Control Development For The Pumping Source Of All Solid-state Ultraviolet Lasers

Ultraviolet(UV) laser with a short wavelength, good focusing performance and cold working, making it widely used in medical, high resolution spectroscopy, optical communication, micro processing and other fields. In recent years, laser diode-pumped all solid-state UV laser has become the main direction of development of UV lasers, has high efficiency, small size, high repetition rate and stable performance etc. The laser diode is a relatively sensitive device. Current and temperature changes will affect the stability of the wavelength and power of laser diode, thereby affecting the performance of the UV laser. Therefore, it is of great practical significance to develop a constant current drive circuit of current continuously adjustable and high stability and a high precision temperature control system.This paper is a laser-diode(LD) power supply design which mainly consists of a LD constant current drive circuit, a high precision temperature control system, a control core of DSP F28335 and interactive features constituted by keys and liquid crystal display panel. Compared the feedback voltage value by the high-precision current detecting resistor PBV-R010 with the preset value, the comparative value was processed by analog proportional-integral amplifying circuit, a real-time output control voltage value was sent to adjust the degree of pass-off of power regulator IRF150 N and then adjust the current. In addition, there were hardware and software dual-overcurrent protection and delay soft start function to prevent damage to the laser diode in the constant current drive circuit. A constant current module was designed to drive semiconductor cooler in the high precision temperature control system. The current of constant current module was changed to control the thermoelectric cooler cooling capacity. The optimal control parameters of proportion-integration-differentiation algorithm was set, which to realize high precision temperature control.The circuit system was continuously tested for 6h at 5~26?,the constant circuit driving and temperature control of dual 50 W high power laser diode. The drive circuit was adjustable in 0~8.8A current range, the current control accuracy which was less than ±0.01 A and stability reached 0.13% when the drive circuit was working long hours at 7.5A. The temperature control accuracy which was less than ± 0.02 ? in 20 ~ 45 ? temperature range. The results show that the circuit system has engineered value to the development of laser diode-pumped all solid-state UV laser for high precision and good stability of the current temperature control.