Synthetic dimensions (SDs) opened the door for exploring previously inaccessible phenomena in high-dimensional space. However, construction of synthetic l
Synthetic dimensions (SDs) opened the door for exploring previously inaccessible phenomena in high-dimensional space. However, construction of synthetic lattices with desired coupling properties is a challenging and unintuitive task. Here, we use deep learning artificial neural networks (ANNs) to construct lattices in real space with a predesigned spectrum of mode eigenvalues, and thus to validly design the dynamics in synthetic mode dimensions. By employing judiciously chosen perturbations (wiggling of waveguides at desired frequencies), we show resonant mode coupling and tailored dynamics in SDs. Two distinct examples are illustrated: one features uniform synthetic mode coupling, and the other showcases the edge defects that allow for tailored light transport and confinement. Furthermore, we demonstrate morphing of light into a topologically protected edge mode with modified Su–Schrieffer–Heeger photonic lattices. Such an ANN-assisted construction of SDs may advance toward “utopian networks,” opening new avenues for fundamental research beyond geometric limitations as well as for applications in mode lasing, optical switching, and communication technologies.show less
The pseudo-magnetic field, an artificial synthetic gauge field, has attracted intense research interest in the classical wave system. The strong pseudo-ma
The pseudo-magnetic field, an artificial synthetic gauge field, has attracted intense research interest in the classical wave system. The strong pseudo-magnetic field is realized in a two-dimensional photonic crystal (PhC) by introducing the uniaxial linear gradient deformation. The emergence of the pseudo-magnetic field leads to the quantization of Landau levels. The quantum-Hall-like edge states between adjacent Landau levels are observed in our designed experimental implementation. The combination of two reversed gradient PhCs gives rise to the spatially nonuniform pseudo-magnetic field. The propagation of the large-area edge state and the interesting phenomenon of the snake state induced by the nonuniform pseudo-magnetic field is experimentally demonstrated in a PhC heterostructure. This provides a good platform to manipulate the transport of electromagnetic waves and to design useful devices for information processing.show less
Non-line-of-sight (NLOS) imaging has emerged as a prominent technique for reconstructing obscured objects from images that undergo multiple diffuse reflec
Non-line-of-sight (NLOS) imaging has emerged as a prominent technique for reconstructing obscured objects from images that undergo multiple diffuse reflections. This imaging method has garnered significant attention in diverse domains, including remote sensing, rescue operations, and intelligent driving, due to its wide-ranging potential applications. Nevertheless, accurately modeling the incident light direction, which carries energy and is captured by the detector amidst random diffuse reflection directions, poses a considerable challenge. This challenge hinders the acquisition of precise forward and inverse physical models for NLOS imaging, which are crucial for achieving high-quality reconstructions. In this study, we propose a point spread function (PSF) model for the NLOS imaging system utilizing ray tracing with random angles. Furthermore, we introduce a reconstruction method, termed the physics-constrained inverse network (PCIN), which establishes an accurate PSF model and inverse physical model by leveraging the interplay between PSF constraints and the optimization of a convolutional neural network. The PCIN approach initializes the parameters randomly, guided by the constraints of the forward PSF model, thereby obviating the need for extensive training data sets, as required by traditional deep-learning methods. Through alternating iteration and gradient descent algorithms, we iteratively optimize the diffuse reflection angles in the PSF model and the neural network parameters. The results demonstrate that PCIN achieves efficient data utilization by not necessitating a large number of actual ground data groups. Moreover, the experimental findings confirm that the proposed method effectively restores the hidden object features with high accuracy.show less
Integrated optical gyroscopes (IOGs) have been an efficient tool for numerous applications in various fields, including inertial navigation, flight contro
Integrated optical gyroscopes (IOGs) have been an efficient tool for numerous applications in various fields, including inertial navigation, flight control, and earthquake monitoring. Here, we review the progress of integrated optical gyroscopes based on two categories of integrated interferometric optical gyroscopes (IIOGs) and integrated resonant optical gyroscopes (IROGs).show less
We use a broad Gaussian beam with perturbations to motivate rogue waves in a two-dimensional optical induced lattice. In a linear situation, we fail to observe RWs. Nevertheless, under a nonline
We use a broad Gaussian beam with perturbations to motivate rogue waves in a two-dimensional optical induced lattice. In a linear situation, we fail to observe RWs. Nevertheless, under a nonlinear condition, the probability of RWs in the lattice is less than that in a homogeneous medium. Additionally, we obtain a shorter long-tails distribution of probability density function in an optical lattice.show less
Frequency-modulated continuous-wave (FMCW) Lidar has the characteristics of high-ranging accuracy, noise immunity, and synchronous speed measurement, which is the candidate for the next generati
Frequency-modulated continuous-wave (FMCW) Lidar has the characteristics of high-ranging accuracy, noise immunity, and synchronous speed measurement, which is the candidate for the next generation of vehicle Lidar. In this work, an FMCW Lidar works at single-photon level is demonstrated based on quantum compressed sensing, and the target distance is recovered from the sparse photon detection, in which the detection sensitivity, bandwidth, and compression ratio are improved significantly. Our system can achieve 3 GHz bandwidth detection at photon count rates of a few thousand, making ultra-long distance FMCW Lidar possible.show less
The suppression of polarization crosstalk in PZT phase modulators as a key error source has been challenging for open-loop fiber optic gyroscopes (FOGs). We developed a polarization-diversity op
The suppression of polarization crosstalk in PZT phase modulators as a key error source has been challenging for open-loop fiber optic gyroscopes (FOGs). We developed a polarization-diversity optical frequency domain reflectometry(OFDR) to measure distributed modulation polarization error in the modulator. The error contributes 8×10−6 rad to FOG’s bias instability. By using a UV-fabricated in-fiber λ/4 waveplate and polarization-mode converter with fiber taper technology, the modulation error has been suppressed by 15 dB in assembled FOGs. This approach reduced error with temperature from 25 °/h to 0.7 °/h, meeting the requirements of control-level gyroscopes with bias errors less than 1 °/h.show less
Isotope shifts among different isotopes can be effectively addressed using narrow-linewidth lasers, facilitating laser isotope separation and achieving significant enrichment at a single stage.
Isotope shifts among different isotopes can be effectively addressed using narrow-linewidth lasers, facilitating laser isotope separation and achieving significant enrichment at a single stage. The separation of potassium isotopes, employing optical pumping and magnetic deflection, has proven to be efficient. To further improve the enrichment of 40K, we introduce 2D transverse cooling to minimize the divergence angle. Through this modification, we demonstrate enrichment of 40K, elevating it from 0.012% to 12%-20%. This represents an enrichment increase by three orders of magnitude, surpassing our previous result by one order. Our method is particularly well-suited for isotope enrichment of elements with extremely low abundance.show less