具有可调参数(例如波长、强度、脉冲宽度和激光状态)的可调谐超快激光器是下一代智能光源的理想选择。由于超快系统内复杂的非线性效应，以方便可控的方式对超快光纤激光器中的激光状态主动控制(LSAC)，特别是被动锁模，提出了挑战。
面内对称性降低的各向异性低维材料表现出偏振相关特性，为紧凑型可调谐光子器件提供了额外的自由度。
在《光：科学与应用》杂志上发表的一篇新论文中，国防科学技术大学高级交叉学科学院周璞教授领导的科学家团队、苏州纳米技术与纳米研究院张凯教授领导的科学家团队在《光：科学与应用》上发表了一篇新论文。中国科学院仿生学研究所及其同事通过基于准一维层状材料切换器的偏振控制实现了传统孤子(CS)和类噪声脉冲(NLP)之间的LSAC。
偏振敏感的非线性光学响应有利于Ta 2 PdS 6基锁模激光器维持两种激光态，即CS和NLP。单光纤激光器中的激光状态是可切换的，其机制通过数值模拟揭示。通过采用激光作为可编码光源，数字编码在该平台中得到了进一步演示。
a，CS态激光器的相位噪声特性。b，NLP态激光器的相位噪声特性。两种不同状态的脉冲噪声性能表明，CS状态的相位噪声(定时抖动)优于NLP。c，25 个连续往返的单次光谱的 DFT 记录 d，基于色散傅里叶变换技术的 NLP 光谱的六个典型帧。通过色散傅立叶变换技术测量的 NLP 光谱的侧翼因镜头而异，但与光谱仪相比，带宽基本保持不变。六个典型的逐帧谱轨迹更直观地说明了 NLP 谱的演变。其光谱的最强峰值在中心波长处交替出现，而且边带的演变相当混乱。这种现象可以归因于 NLP 的特性，即由一系列幅度和持续时间随机分布的子脉冲组成的脉冲簇。
In the pump power range of 450mw ~ 830mw, switching between two different laser states, CS and NLP, can be achieved at a constant pump power by simply adjusting the tilt angle of the polarization controller. The output spectrum of a Ta2PdS6-based ultrafast fiber laser for a continuous conversion operation over a period of 3.5 h. The spectra of the two laser states before and after the conversion are unchanged, demonstrating the stability of the state switching of the ultrafast fiber laser based on Ta2PdS6. Credit: Zixin Yang, Qiang Yu, Jian Wu, Haiqin Deng, Yan Zhang, Wenchao Wang, Tianhao Xian, Luyi Huang, Junrong Zhang, Shuai Yuan, Jinyong Leng, Li Zhan, Zongfu Jiang, Junyong Wang, Kai Zhang, and Pu Zhou
a, The phase noise characteristics of the CS state laser. b, The phase noise characteristics of the NLP state laser. The pulse noise performance of the two different states shows that the phase noise (timing jitter) of the CS state is better than the NLP. c, DFT recording of single-shot spectra over 25 consecutive round trips d, The six typical frames of NLP spectra based on the dispersive Fourier transform technique. The flanking of the NLP spectra measured by the dispersive Fourier transform technique varies from shot to shot, but the bandwidth remains essentially unchanged when compared with that of the spectrometer. Six typical frame-by-frame spectral traces illustrate the evolution of the NLP spectrum more visually. The strongest peaks of its spectrum alternate at the center wavelength, and the evolution of the sidebands is rather chaotic. The phenomenon can be attributed to the properties of NLP, i.e., a cluster of pulses consisting of a series of sub-pulses with randomly distributed amplitudes and durations. Credit: Zixin Yang, Qiang Yu, Jian Wu, Haiqin Deng, Yan Zhang, Wenchao Wang, Tianhao Xian, Luyi Huang, Junrong Zhang, Shuai Yuan, Jinyong Leng, Li Zhan, Zongfu Jiang, Junyong Wang, Kai Zhang, and Pu Zhou
偏振控制是调整腔内参数和控制激光工作状态的实用方法。
总结可调谐超快激光器的主要发现，科学家们说：“(1)各向异性准一维层状材料Ta 2 PdS 6被用作可饱和吸收体，通过偏振-有效地调制超快系统中的非线性参数。依赖吸收;(2)偏振敏感的非线性光学响应有助于Ta 2 PdS 6基锁模激光器维持两种不同类型的激光状态，即CS和NLP;(3)激光状态可以在单光纤激光器，其机制通过数值模拟揭示;(4) 通过使用激光器作为可编码光源，在该平台中进一步演示了数字编码。”
“在单个超快光纤激光器系统中不同脉冲激光模式的受控和稳定切换代表了紧凑型超快光子学的重大进步，这为通信编码和光切换等应用提供了前景。”
