The nonlinear tuning technique of a DFB laser using frequency predistortion procedures

摘要

The frequency modulation continuous wave (FMCW) light detection and ranging (LIDAR) has drawn enormous attention and intense effort. In this paper a nonlinear tuning technique for a DFB laser which is driven by a home-made LD driver is proposed and developed experimentally for generation of linearly chirped light which may be applied in FMCW LIDAR systems. A frequency predistortion procedure based on nonlinear tuning technique can be applied to the LD driver which could be controlled by a field-programmable gate array (FPGA) module. And the frequency predistortion procedure can be used iteratively until the desired linearity of the chirped optical waves is achieved before the PLL is introduced in. This technique can be seen as an effective way to increase the acquisition bandwidth of the PLL significantly so that the trade-off between large acquisition frequency and narrow bandwidth of the PLL is no longer a problem.