High stability DFB laser driving power supply utilized in infrared gas detection

In order to meet the requirements of infrared gas detection for high performance laser driving power supply, the PID control algorithm was adopted, a high stability DFB laser driving power supply was designed and manufactured. Its hardware mainly included signal generation module, voltage-controlling current source module, circuit protection module. The system had the function of output current protection. In the signal generation module, the sine wave was generated by DDS and then square waves was generated through a comparator. At the same time, DA conversion technique was adopted to realize the output of DC wave, triangular wave and sawtooth wave. Meanwhile, in respect of control scheme, the current high stability was effectively ensured by the use of PID control algorithm and veep negative feedback. With this driver, the driving test was performed on a DFB laser with a center wavelength at 1 563.09 nm. The results show that the driver has the function of the output waveform type, amplitude and frequency can be changed by digital control, the current amplitude ranges from 0 to 1 A and the frequency range is from 1 Hz to 1 MHz. The frequency resolution is 1 Hz. The linearity of the system is 99.93% and the long term output current stability reached 0.019 7%.