基于注入锁定和时域综合的倍频三角波产生技术

Frequency Doubled Triangular Waveform Generation Based on Injection Locking and Time-Domain Synthesis

提出并验证了一种利用载波抑制调制和半导体激光器注入锁定相结合的倍频三角波产生方案。方案中激光器发出的连续光经正弦信号驱动的马赫-曾德尔调制器进行抑制载波调制后分为两路,一路保持不变,另一路注入分布反馈激光器锁定放大调制光的高阶谐波分量,获得六倍频信号。两路信号经相位和功率比控制,合路后在光电探测器中叠加产生二倍频的三角波信号。实验利用频率为3GHz和4GHz的正弦调制信号产生了6GHz和8GHz的二倍频全占空三角波信号。理论分析和实验结果均证明了此方案的可行性,避免了复杂的谱线操作,所提方案更加简单高效,在高重复频率三角波产生方面有显著优势。

A new approach to generate frequency doubled triangular waveform signals is proposed and verified through the combination of carrier suppression modulation and semiconductor laser injection locking. In the scheme, the continuous wave emitted by the external cavity tunable laser is modulated by a sinusoidal signal through Mach-Zehnder modulator to suppress the optical carrier. The modulated signal is divided into two branches. One signal remains unchanged and the other is launched into a distributed feedback laser to select and amplify higher-order harmonic components for six-fold signal generation. After controlling the relative phase and power ratio of the two signals, we achieve frequency doubled triangular waveform by overlapping the signals in the photodetector. In the experiment, sinusoidal modulation signals at the frequencies of 3 GHz and 4 GHz are applied to generate full duty frequency doubled triangular waveform with a frequencies of 6 GHz and 8 GHz successfully. Both theoretical analysis and experimental results prove that the scheme is feasible. It is a simpler and more efficient way to avoid the complex spectral line operation. Moreover, it has a distinct advantage in high-frequency triangular waveform generation.