Drive design and performance test of a tunable DFB laser

In order to meet the requirements of TDLAS technology and to ensure the optical wavelength stability and the optical power stability of the laser light source, we design the DFB (distributed feedback) laser drive system using STM32 as the controller. The hardware circuit mainly includes drive current control circuit, constant temperature control circuit and laser optical power monitoring circuit. Then, the performance test of 1550nm DFB laser is carried out. Test condition is under the normal atmospheric temperature and ensuring constant control current. The test shows that the range of the laser output wavelength is 3pm and the optical power fluctuation is less than 0.005mW after preheating an hour. The stability of the optical wavelength and optical power is excellent.