相较于单涡旋光束，涡旋阵列光束能够扩充信息的传输容量，研究其传输特性对其光通信应用具有重要意义。本文选取阶数为n的螺旋因斯-高斯(HIG_n,n)模式，采用海上大气折射率变换的功率谱，模拟海面大气湍流。基于相位屏法研究了一维阵列涡旋光束在海面大气湍流中光强、相位、闪烁因子和质心漂移的变化情况。结果表明：（1）HIG_n,n模式的闪烁因子和质心漂移标准差随湍流强度以及大气湍流内尺度的增加而增加；（2）n为奇数的HIG_n,n模式的闪烁因子随着阶数的增大而减小，且高于n为偶数的HIG_n,n模式；（3）阶数n>1的HIG_n,n模式比LG_0,1模式具有更好的稳定性；（4）阶数越高，HIG_n,n模式的质心漂移标准差越小。其次，选取线性阵列涡旋光束（LAVBs）进行对比，研究得出虽然LAVBs比HIG光束具有更好的传输性能，但由于HIG光束具有独特的结构，故可适用于不同的应用场景。最后，分析了椭圆参量和椭圆环数对HIG模式传输的影响，结果表明适当地增大椭圆参量或椭圆环数有助于提高HIG模式的抗湍流能力。本文研究结果对涡旋光束的海上应用具有指导意义。

Multimode photonic quantum memory could enhance the information processing speed in a quantum repeater-based quantum network. A large obstacle that impedes the storage of the spatial multimode in a hot atomic ensemble is atomic diffusion, which severely disturbs the structure of the retrieved light field. In this paper, we demonstrate that the elegant Ince-Gaussian (eIG) mode possesses the ability to resist such diffusion. Our experimental results show that the overall structure of the eIG modes under different parameters maintains well after microseconds of storage. In contrast, the standard IG modes under the same circumstance are disrupted and become unrecognizable. Our findings could promote the construction of quantum networks based on room-temperature atoms.

Laguerre-Gaussian (LG) modes, carrying the orbital angular momentum of light, are critical for important applications, such as high-capacity optical communications, superresolution imaging, and multidimensional quantum entanglement. Advanced developments in these applications demand reliable and tunable LG mode laser sources, which, however, do not yet exist. Here, we experimentally demonstrate highly efficient, highly pure, broadly tunable, and topological-charge-controllable LG modes from a Janus optical parametric oscillator (OPO). The Janus OPO featuring a two-faced cavity mode is designed to guarantee an efficient evolution from a Gaussian-shaped fundamental pump mode to a desired LG parametric mode. The output LG mode has a tunable wavelength between 1.5 and 1.6 μm with a conversion efficiency >15 % , a controllable topological charge up to 4, and a mode purity as high as 97%, which provides a high-performance solid-state light source for high-end demands in multidimensional multiplexing/demultiplexing, control of spin-orbital coupling between light and atoms, and so on.

The study of structured laser beams has been one of the most active fields of research for decades, particularly in exploring laser beams with orbital angular momentum. The direct generation of structured beams from laser resonators is deeply associated with the formation of transverse modes. The wave representations of transverse modes of spherical cavities are usually categorized into Hermite–Gaussian (HG) and Laguerre–Gaussian (LG) modes for a long time. Enormous experimental results have revealed that the generalized representation for the transverse modes is the Hermite–LG (HLG) modes. We make a detailed overview for the theoretical description of the HLG modes from the representation of the spectral unitary group of order 2 in the Jordan–Schwinger map. Furthermore, we overview how to derive the integral formula for the elliptical modes based on the Gaussian wave-packet state and the inverse Fourier transform. The relationship between the HLG modes and elliptical modes is linked by the quantum Fourier transform. The most striking result is that the HLG modes can be exactly derived as the superposition of the elliptical modes without involving Hermite and Laguerre polynomials. Finally, we discuss the application of the HLG modes in characterizing the propagation evolution of the vortex structures of HG beams transformed by an astigmatic mode converter. This overview certainly provides not only a novel formula for transverse modes, but also a pedagogical insight into quantum physics.