桶状抽样型电磁量能器（Electromagnetic Calorimeter，Ecal）是俄罗斯在建的重离子超导同步加速器（Nuclotron-based Ion Collider faсility，NICA）中多功能探测谱仪（Multi-Purpose Detector，MPD）上的一个重要探测器，主要用于探测10 MeV至几个GeV能域内电子和光子的能量、时间、位置信息。基于Geant4软件，使用单能电子研究了入射位置及闪烁体层数对探测器模块（module）能量分辨率的影响，闪烁体层数和电子能量对探测器单元（tower）时间分辨率和Ecal位置分辨率的影响。模拟结果表明：随着电子入射位置由module边缘向中心移动，闪烁体内能量沉积由718 MeV增加至758 MeV；在tower长度为415.5 mm条件下，随着闪烁体层数增加，module能量分辨率变差，tower时间分辨率变好，Ecal位置分辨率变差。在兼顾量能器的各项性能后，tower中闪烁体最佳层数为211层，Ecal能量分辨率好于4.35%，时间分辨率小于112 ps，位置分辨率好于2 mm；在相同条件下，电子能量越高电磁量能器的时间分辨率和位置分辨率越好。

Engineering of the orbital angular momentum (OAM) of light due to interaction with photonic lattices reveals rich physics and motivates potential applications. We report the experimental creation of regularly distributed quantized vortex arrays in momentum space by probing the honeycomb and hexagonal photonic lattices with a single focused Gaussian beam. For the honeycomb lattice, the vortices are associated with Dirac points. However, we show that the resulting spatial patterns of vortices are strongly defined by the symmetry of the wave packet evolving in the photonic lattices and not by their topological properties. Our findings reveal the underlying physics by connecting the symmetry and OAM conversion and provide a simple and efficient method to create regularly distributed multiple vortices from unstructured light.

The sensitivity of optical measurement is ultimately constrained by the shot noise to the standard quantum limit. It has become a common concept that beating this limit requires quantum resources. A deep-learning neural network free of quantum principle has the capability of removing classical noise from images, but it is unclear in reducing quantum noise. In a coincidence-imaging experiment, we show that quantum-resource-free deep learning can be exploited to surpass the standard quantum limit via the photon-number-dependent nonlinear feedback during training. Using an effective classical light with photon flux of about 9×104 photons per second, our deep-learning-based scheme achieves a 14 dB improvement in signal-to-noise ratio with respect to the standard quantum limit.

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.

By taking advantage of the optical induction method, a non-Hermitian photonic graphene lattice is efficiently established inside an atomic vapor cell under the condition of electromagnetically induced transparency. This non-Hermitian structure is accomplished by simultaneously modulating both the real and imaginary components of the refractive index into honeycomb profiles. The transmitted probe field can either exhibit a hexagonal or honeycomb intensity profile when the degree of non-Hermiticity is effectively controlled by the ratio between imaginary and real indices. The experimental realization of such an instantaneously tunable complex honeycomb potential sets a new platform for future experimental exploration of non-Hermitian topological photonics. Also, we demonstrate the Talbot effect of the transmitted probe patterns. Such a self-imaging effect based on a non-Hermitian structure provides a promising route to potentially improve the related applications, such as an all-optical-controllable Talbot–Lau interferometer.