Cottonnunez1881

Simulation and experimental results verify that the proposed method significantly suppresses the ripple-like artifacts in phase maps induced by fringe harmonics without capturing extra many fringe patterns or correcting the non-sinusoidal profiles of fringes. In addition, this method involves a quasi-pointwise operation, enabling correcting position-dependent phase errors and being helpful for protecting the edges and details of the measurement results from being blurred.We study theoretically and experimentally the influence of the obstacle position separation from the source on the self-healing capacity of partially coherent beams using Hermite-Gaussian correlated Schell-model beams as a case in point. We establish that the shorter the distance between the obstacle and the source plane and the longer the distance between the obstacle and the observation (receiver) plane, the better the self-healing capacity of the beams. In addition, a similarity degree between the reconstructed and original beams is introduced to quantify the self-healing capacity of partially coherent beams. The derived interesting results may find applications in optical information processing, image transmission, and recovery.The topological effects accompanied by phase structuring during the interaction between optical fields and nonlinear crystals are presented and demonstrated. The topological phase transition in the optical field is determined during the quasi-phase matched second harmonic frequency conversion process. The mapping relationship between the corresponding topological invariant and the phase parameters is derived, and two critical transition points are obtained. The transition of the total orbital angular momentum (OAM) in the propagation direction is verified to be the physical origin of this topological regulation through OAM spectrum analysis. This work provides a new perspective for examining nonlinear light-matter interaction, which can inspire promising applications in structured light generation and optical information processing.Continuously tunable polymer lasing was achieved in one-dimensional, two-dimensional, and compound chirped cavities. The chirped cavity was simply fabricated by using interference lithography and spin coating. Two-dimensional and compound chirped cavities were obtained by employing oblique exposure and double exposure, respectively. The tunability range of two-dimensional chirped cavities was much wider than that of one-dimensional chirped cavities, which varied from 557 nm to 582 nm. Alectinib datasheet The interaction between lasing modes was studied in the compound cavity by introducing an additional nanostructure into the two-dimensional chirped cavities. The threshold of the compound chirped cavities changed with the coupling strength between lasing modes. These results may be helpful for designing compact polymer laser sources.We construct the ZnO-based superluminescent light-emitting diodes (SLEDs) by spin-coating ZnO nano-particles onto p-GaN/sapphire substrate. By inserting another thin Al layer to form an n-ZnO/Al/n-ZnO/p-GaN sandwich structured SLD, the intensities of the photoluminescence and electroluminescence were greatly enhanced, which can be attributed to the surface plasmon resonance of this Al layer. The tendency of the intensities of the entire electroluminescence spectra shows a super-linearly behavior with increasing the forward bias. Besides, the spectral bandwidth is narrowed down enormously owing to the achievement of the SLD. Furthermore, the interfacial emissions between ZnO/GaN are effectively suppressed by partially oxidizing the Al layer.Metasurfaces have proven their great application potentials in terahertz (THz) wave modulations. However, realizing an active metasurface retaining lensing functionality in the THz frequency regime is still highly desired. Here a metalens, featuring electrically tunable focal length, based on propagation phase delay, is proposed and demonstrated experimentally. To have full control over the designed lens functionality, a gold thin film etched with a C-shaped aperture antenna array covered by monolayer graphene is used. By applying a bias voltage to the graphene, the phase control of the antenna array is changed, and thus the focus of the linearly polarized THz beam can be flexibly tuned from 7.13mm to 8.25mm. The proposed approach has a promising perspective for a variety of applications in communication, reconfigurable flat optics and real-time imaging in THz regime.We report the first observation of laser cooling in Yb3+KYW and validate the results by comparison with experiments in the well-studied material Yb3+YAG. Radiation from a single-mode TiAl2O3 laser was used to achieve cooling of 1.5 K/W in 1% YbKYW at 1025 nm, comparing well with the reference material 3% YbYAG which cooled by 3.5 K/W at 1030 nm under open lab conditions. Experimental results for KYW crystals mounted on aerogels and doped with 1-20% Yb were in excellent agreement with the theoretical dependence of cooling power on the Yb absorption spectrum. Elimination of thermal conduction through the sample support structure was found to permit the attainment of lower temperatures and to simplify modeling of radiation balance conditions in self-cooled lasers with longitudinal thermal gradients. Contrary to the notion that more coolant ions yield higher cooling power, concentrations of Yb over 1% caused re-absorption of luminescence in KYW crystals, leading to a progressive red shift in the optimal cooling wavelength and the prevention of laser cooling altogether in a 20% sample at room temperature. The prospect of attaining radiation-balanced lasing in commercially-available tungstate crystals is evaluated.Space division multiplexing elastic optical networks (SDM-EONs) with multi-core fiber (MCF) are the promising candidate for future optical networks due to their high transmission capacity and high flexibility. However, the inherent defects of inter-core crosstalk and spectrum fragmentation may have some negative impact on the performance of SDM-EONs. A deep learning and hierarchical graph-assisted crosstalk-aware fragmentation avoidance (DLHGA) strategy is proposed in this paper. Firstly, we introduce a deep learning (DL) model to predict future requests, so as to achieve reasonable scheduling of resource in advance. Then, considering the inter-core crosstalk of MCF, we abstract the core, spectrum and time resource as a three-dimensional (3D) model with the hierarchical graphs. Therefore, the resource allocation process is simplified to be mitigating the crosstalk and fragmentation from the perspective of inter-core and intra-core, respectively. Finally, based on DL traffic prediction and different characteristics of hierarchical graph, we present an adaptive resource allocation algorithm considering relieving core adjacency and downgrading modulation format to achieve efficient resource scheduling.