设计了基于多模干涉效应锁模的掺铒光纤激光器，利用渐变折射率多模光纤实现了锁模脉冲输出。通过控制泵浦功率，调节腔内偏振控制器，实验获得中心波长为1 528 nm的展宽脉冲，3 dB带宽为37.2 nm，脉冲宽度为973.2 fs。在腔外进行色散补偿，将展宽脉冲的脉冲宽度压缩至280.1 fs。此外，通过提高总泵浦功率至961.1 mW并微调偏振控制器，获得了色散管理孤子分子脉冲输出，调制周期为0.32 nm，对应的脉冲间隔为24.1 ps。实验采用多模光纤内置在偏振控制器中的锁模结构，突破了对多模光纤长度的限制，激光器结构紧凑，具有出色的稳定性。

We fully demonstrate the special requirements of a mid-infrared all-optical wavelength converter. The construction mechanism of a 2.05 µm all-optical wavelength converter based on the single-wall carbon nanotube (SWCNT) is proposed. Systematic experiments are carried out, and the converter device is successfully developed. With the assistance of SWCNT-coated microfiber, the conversion efficiency up to -45.57dB is realized, and the tuning range can reach 9.72 nm. The experimental results verify the correctness of the proposed mechanism and the feasibility of the converter device so that it can be a new technical approach for all-optical wavelength conversion beyond 2 µm. We believe the research can extend the application of this composite waveguide in the field of all-optical communication.

通过实验研究了大气湍流信道下中轨道角动量（OAM）光束与高斯光束的传输性能，并将两种光束的传输性能进行对比。实验以加载调制信号的OAM光束以及高斯光束为传输载波，分别测量了在大气湍流信道下两种光束的光束展宽、指向偏差、功率抖动以及误码率。实验结果表明：在大气湍流信道中传输后，OAM光束相比高斯光束，光束展宽减少10.5%，功率抖动的方差下降0.13，指向偏差的散布圆直径减小30.4%，并且光束中心更集中于接收面中心；OAM光束载波系统的最低探测灵敏度达到−28.97 dBm，相比高斯光束提升2.5 dB。实验结果证明了在大气湍流信道传输中，OAM光束比高斯光束受到湍流的影响更小，并且随着湍流强度的增加，OAM光束恶化程度远小于高斯光束。实验的结论为大气湍流信道下自由空间激光通信的发展和应用提供了参考。

设计了一种由类噪声脉冲抽运的全光纤结构平坦超连续谱光源。在色散管理掺铒光纤激光器中通过调节腔内偏振态，在泵浦功率为450 mW时，实现了稳定的类噪声脉冲锁模，锁模脉冲的中心波长为1 600 nm，脉冲宽度为303 fs。在最大泵浦功率为1 W时，谐振腔直接输出功率为8.6 mW。较低的功率无法有效拓展超连续谱宽度，为此设计一种掺铒光纤放大器进行功率放大，放大器最大输出功率为338 mW，将功率放大后的类噪声脉冲耦合进高非线性光纤以产生超连续谱，超连续谱的20 dB光谱范围为1 530 nm～2 300 nm，在1 736 nm～2 134 nm范围内，光谱的平坦度优于0.5 dB。

报道了一种可实现低阈值自启动的全保偏九字腔光纤激光器。谐振腔结构中使用相移器降低锁模阈值，当泵浦功率达到120 mW时，便可实现自启动的传统孤子锁模，中心波长为1530 nm，脉冲宽度为614.6 fs。随后泵浦功率逐渐增大到470 mW，实现了从孤子脉冲到类噪声脉冲的转换，在该锁模状态下的激光器输出功率为63.2 mW，对应的类噪声脉冲能量为5.69 nJ。所搭建的激光器具有低锁模阈值、自启动的优势，并且仅通过调节泵浦功率就能够实现超快脉冲和高能量脉冲间的转换，具有广泛的应用价值。

报道了一种基于非线性偏振旋转效应的被动锁模光纤激光器。采用980 nm分布式反馈激光器作为泵浦源，0.5 m长的高掺杂掺铒光纤作为增益介质。实现了脉冲宽度为822 fs的传统孤子锁模脉冲，输出脉冲的平均功率为2.8 mW，信噪比为55.8 dB。通过微调腔内的偏振控制器，实现了传统孤子脉冲和孤子分子脉冲间的切换，孤子分子的脉冲宽度为312 fs，信噪比为53.86 dB。孤子分子脉冲经掺铒光纤放大器放大后泵浦一段57 m长的高非线性光纤，产生了位于第三近红外窗口（1600 nm～1870 nm）的超连续谱，其20 dB谱宽为355.8 nm。

We integrally demonstrate 2 μm mode-locked pulses performances in all-fiber net anomalous dispersion cavity. Stable mode-locking operations with the center wavelength around 1950-1980 nm can be achieved by using the nonlinear polarization rotation structure and properly designing the dispersion management component. Conventional soliton is firstly obtained with a total anomalous dispersion cavity. Due to the contribution of commercial ultra-high numerical aperture fibers, net dispersion is reduced to -0.077 ps². So that stretched pulse with 19.4 nm optical bandwidth is obtained and the de-chirped pulse-width can reach 312 fs using extra-cavity compression. Under pump power greater than 890 mW, stretched pulse can evolve into noise-like pulse with 41.3 nm bandwidth. The envelope and peak of such broadband pulse can be compressed with up to 2.2 ps and 145 fs, respectively. The single pulse energy of largely chirped stretched and noise-like pulse can reach 1.785 nJ and 1.53 nJ, respectively. Furthermore, extra-cavity compression can also contribute to a significant increase of peak power.