Research On Dual-Channel Semiconductor Laser Drive Technology

The semiconductor laser as a new type of the most practical laser, has the excellent character of high efficiency, good reliability, small size, low weight, long life-time and direct current modulation, and has playing an increasing important role in the field of information and photoelectron. In modern application, output optical power and wavelength spectrum of the semiconductor laser must be stable and fast, and the laser can be easy and flexible controlled and practical. Comparing to the traditional semiconductor laser controller, it has the shortcomings of low control precision, the longer of the system boot time, and uncontinuously adjustable output optical power. A high control precision, double channels and continuously adjustable optical power of laser controller has been sdudied and designed in this paper, the system has high, fast and long stability of optical power and temperature after laboratory tests and practical application. The main research works are as follows:1. The working principle and characteristic of semiconductor laser, as well as the factors affecting the stability of the output optical power are discussed, and the overall plan of a semiconductor laser driver system are designed.2. A precision constant current source for driving semiconductor laser has been studied and designed, based on the current negative feedback control technology. The working principle and the stability of constant current circuit are analysed. It improves the current stability by applying the method of circuit compensation.3. The working principle of semiconductor cooler are analysed, based on the digital PID control algorithm, A constant temperature controller for semiconductor laser has been studied and designed, the temperature controller can stable the the environment temperature of laser rapidly by heating or cooling.4. A CAN bus communication circuit has been designed, it realizes the control of semiconductor laser with double channels, the selection of lasers source and contiuously adjustable optical power. 5. The experimental circuit of dual-channel semiconductor laser with stable optical power output and the corresponding software have been developed. The tests show that the stability of current and temperature reach the system requirement. The output optical power of semiconductor laser has the long term stability±0.006dB.