为获得高效的合成孔径激光雷达信号,提出一种通过精密控制谐振腔提高激光线性调频信号有效功率的方法,并描述了激光器的调频实现。首先,分析驱动信号获得其傅里叶谱,获知调腔信号有效功率低的原因在于调腔器件对信号高次谐波响应较差;通过在谐振腔驱动电路中引入了高次谐波响应模块,最终有效地减小了信号调频波形下降沿,提高了合成孔径激光雷达信号的有效功率。对所获得的调频信号性能指标进行了测试,结果表明,调频周期为1 ms时,调频带宽达到了789 MHz,信号功率中有用功率由72%提高到92%以上。
To obtain a synthetic aperture ladar signal with a high net power rate,a novel method to obtain the Linear Frequency Modulation(LFM) laser signal was presented and the LFM laser experiment was also performed.Detailed Fourier analysis for the driving signal shows that the cavity tuning device can not response the high-order harmonics well.A high-order harmonics response module was introduced into the driving circuit of the cavity resonator to drive the piezoelectric transducer for cavity tuning,so that the trailing edge of the signal was shortened and the net power rate of the signal was improved greatly.Furthermore,the performance of obtained signal was tested and analyzed.The results show that when the FM period is 1 ms,the FM bandwidth is 789 MHz with the FM linearity better than 1.6%.Meanwhile,the net power rate of the signal is raised to 92% from 72%.