The Design Of Semiconductor Laser Based On Embedded System

Semiconductor laser has various kinds of application in industrial production and scientific research for its small volume, light weight, high efficiency and low cost. However, traditional driver circuit of semiconductor laser has many disadvantages such as complex structure, simple function, low control precision and fixed control mode, which limits the further expansion of the semiconductor laser’s application fields.In this paper, in reference to the traditional semiconductor laser driver, a nove laser diode driver circuit based on embedded systems was proposed to solve the problems in existing design. The driving circuit is divided into two parts, one is the embedded control system in the upper layer and the other is the peripheral drive system in the underlying layer. The embedded control system is based on S3C6410processor. Android operating system running on the processor is response for for drive circuit management, real-time monitoring and working status displaying. Based on the extensible markup language (EML), graphical user interface (GUI) has been designed to provide luxuriant control and data display modes to the users. The peripheral drive system controls all the peripheral modules through a PIC microchip control uniter (MCU). With the voltage controlled constant-current module WLD3343and temperature control module WTC3243, the structure of driver has been optimized. High precision ADC and DAC are provided to significantly improve the control accuracy of the system for laser drive current and the operating temperature. Power on delay, temperature alarm and drive current limit are realized with various hardware protection circuits as well as software functions to ensure the safe operation of the laser diode.Both the hardware and software have been tested and the experimental results have shown that the proposed driver design can satisfy the requirement for both accuracy and long-term stability while ensure the safety of laser, which has fully achieved the expected design goals. At the same time the involving of embeded system can provide a convenient ways of parameter setting, monitoring and recording for the user that is quite suitable for the practical applications under various in-field environments.