耗散孤子光纤激光器的量子特性研究

The dissipative soliton is a soliton which has the exchange of matter and energy with the outside world all the time. Compared with the soliton existing in conservative systems or hamiltonian systems, the dissipative soliton is more universally, and it has been widely applied to optics, physics, biology and medicine. On the one hand, the dissipative soliton breaks the peak energy limitation in traditional soliton fiber lasers, overcomes the splitting of light waves, and achieves higher energy pulse output. On the other hand, compared with continuous wave, the dissipative soliton can achieve stronger squeezing, so it has been shown more potential in the development of nonclassical field. However, it is one of the hotspots and difficulties in the international research field that how to combine theory with experiment to achieve stable dissipative soliton with high energy. In this project, we intend to combine theory with experiment to study the dissipative soliton fiber laser based on hybrid mode locking mechanism including nonlinear polarization rotation technology and saturable absorber technology, and obtain high energy and high stable dissipative soliton output, which will provide guarantee for subsequent applications. Based on the self-built high-energy light source and combined with the all-fiber quantum squeezed system, the dissipative soliton squeeze in the quantum field is performed experimentally. A step-to-step gradual optimization from the source of dissipative soliton to the squeezed system was designed, and the systematical coordination of various parameters was performed to obtain the optimal squeezed quantum light field, which can be expected to expand the research scope of the dissipative soliton in quantum information and other fields.

耗散孤子是一种与外界时刻存在着物质和能量交换的孤子。相对存在于保守系统或哈密顿系统的传统孤子，耗散孤子更具有普适性,且已广泛应用于光学、物理学、生物学和医学等学科。耗散孤子一方面突破了传统孤子光纤激光器所受到的能量峰值限制，克服了光波分裂，可以实现高能量脉冲输出；另一方面，耗散孤子相比连续光具有更大的压缩空间，在非经典领域更具潜力。但是，如何理论与实验结合，实现更高能量的稳定耗散孤子输出是目前国际上的研究热点与难点之一。在本项目中，我们拟理论与实验相结合研究基于非线性偏振旋转技术和可饱和吸收体混合锁模的耗散孤子光纤激光器，实现高能量的耗散孤子稳定输出，为后续应用提供保障。据此自建的高能量光源，结合全光纤化的量子压缩装置，对耗散孤子进行量子光场的压缩实验，通过逐级优化各个环节，协同调节各个参数，获得最优压缩光场，拓展耗散孤子在量子信息等领域的研究范围。

非线性光纤系统是研究各类孤子脉冲的理想平台，耗散孤子脉冲可以突破传统孤子光纤激光器所受到的能量峰值限制，克服光波分裂，能够实现高能量脉冲输出，在光学、物理学、生物学和医学等学科有广泛的应用前景。因此，高能量高稳定性耗散孤子的产生和相应特性研究具有重要意义。本项目采用理论与实验相结合的方式研究了基于可饱和吸收体锁模的耗散孤子光纤激光器。设计了耗散孤子光纤激光器的理论模型，建立了CGL方程，利用修正的双线性方法解析研究了CGL方程。研究了色散、非线性、增益、损耗等参数对耗散孤子稳定性的影响，揭示了光纤激光器中影响耗散孤子产生、传输及稳定性的激光参数。项目成员合理优化了腔内色散量、泵浦功率、吸收体器件的调制深度及透射曲线特征等参数，获得了高稳定性的耗散孤子输出。分析研究了耗散孤子的光谱特征，实现了高功率、高稳定性的超快耗散孤子输出，实验研究了孤子的矢量偏振特性。在光纤环形腔外，搭建了二阶色散补偿系统，对振荡器直接产生的耗散孤子脉冲进行压缩，产生了孤子脉冲的振幅压缩态。本项目开展的耗散孤子脉冲理论及实验研究，有助于加深对耗散孤子的全面认知，而且对开发紧凑、高效可靠的超短脉冲光源以及实现高脉冲能量输出具有一定的指导意义。此外，相关研究结果对基础物理、超快光学、材料科学等前沿交叉学科的发展有一定的促进作用，具有丰富的物理内涵和广阔的应用前景。