Wang Ju, Gao Ye, Yu Jinlong, Luo Hao, Su Xuemin, Zhang Shiyu, Zhang Ruize, Ma Chuang
School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
Micromachines (Basel). 2024 Oct 18;15(10):1269. doi: 10.3390/mi15101269.
Classical frequency-stabilized lasers have achieved high-frequency stability and reproducibility; however, their extensive wavelength spacing limits their utility in various scenarios. This study introduces a novel frequency-stabilized laser scheme that integrates a Fabry-Perot etalon (FPE) with digital control technology and wavelength modulation techniques. The FPE, characterized by multiple transmission peaks at minimal frequency intervals, provides stable frequency references for different lasers, thereby enhancing the system's flexibility and adaptability. An error signal is derived from the first-order differentiation of the FPE's transmission curve. A 180° phase difference was observed in the feedback output signal when the laser's central frequency diverged from the reference, determining that the direction of the frequency control was accordingly determined.Employing feedback control, the laser's output frequency is stabilized at the transmission peak frequency of the FPE. Experimental results demonstrate that this stabilization scheme effectively locks the laser's output wavelength to different transmission peak frequencies of the FPE, achieving 25 GHz wavelength spacing. The frequency stability is improved by two orders of magnitude on a second-level timescale, maintained within hundreds of kHz, equating to a frequency stability level of 10.
经典的频率稳定激光器已经实现了高频率稳定性和可重复性；然而，它们广泛的波长间隔限制了它们在各种场景中的应用。本研究介绍了一种新颖的频率稳定激光方案，该方案将法布里-珀罗标准具（FPE）与数字控制技术和波长调制技术相结合。FPE的特点是在最小频率间隔处有多个传输峰值，为不同的激光器提供稳定的频率参考，从而提高了系统的灵活性和适应性。误差信号由FPE传输曲线的一阶微分得出。当激光器的中心频率偏离参考值时，在反馈输出信号中观察到180°的相位差，据此确定频率控制的方向。采用反馈控制，激光器的输出频率稳定在FPE的传输峰值频率上。实验结果表明，这种稳定方案有效地将激光器的输出波长锁定到FPE的不同传输峰值频率上，实现了25 GHz的波长间隔。在二级时间尺度上，频率稳定性提高了两个数量级，保持在数百kHz以内，相当于10的频率稳定水平。
