High speed photoelectronic optical phased arrays are demonstrated by vertically arranged GaAs-AlGaAs slab waveguides. The optical phased arrays are composed of 15-channel independently tuned waveguide with end-fire emission. We achieve a very fast beam steering step response of 0.34 µs, beam divergence of 4.7°, and beam steering ranges of around 30°with side lobe level better than 8 dB. The presented optical phased arrays provide a superior approach for high speed beam steering on a nano-photoelectronic integrated chip.

We propose an imaging system with scanning feedback of an optical phased array (OPA) for moving targets with unknown speed. The system combines OPA scanning velocimetry capability with OPA-based ghost imaging to enable trajectory tracking of targets moving within the field-of-view of the system while accomplishing image reconstruction. The proposed system can perform image reconstruction for millimeter-scale moving targets placed up to 20 m away from the camera. The system can be applied in areas such as autonomous driving and high-resolution imaging.

The beam quality of coherent beam combing (CBC) is significantly affected by the beam array schemes, which are regular hexagon arrays in most research. Here, we propose a bio-inspired Fermat spiral array (FSA) for large-array CBC, for the first time to our knowledge. The far-field distribution and beam quality of CBC with various designed FSAs was investigated numerically and experimentally; the simulated and experimental results agreed with each other. The power in the bucket (PIB) increased with the central space density of the FSA, accompanying by the weakening of the far-field sidelobes. In addition, for the FSA with constant space density, the PIB increased, and sidelobes weakened with the increase of the array filling factor. The FSA could effectively improve the PIB and weaken the sidelobe of the CBC far field by the aperiodic and nonuniform space density arrangement, compared to the regular arrays. These results provide a new approach for the beam arrangement of large-array CBC.

Existing optical phased array (OPA) dynamic imaging techniques can only be used to perform image reconstruction of targets undergoing simple motion. This paper proposes an imaging technique for targets undergoing complex motion based on recent research in the OPA-LiDAR field. To this end, the proposed technique combines two sub-algorithms: an OPA scanning algorithm and a compressed-sensing ghost imaging (CS-GI) technique. The reliability of the proposed technique is verified based on theoretical analysis, numerical calculations, and experimental validation. The first sub-algorithm is an innovative adaptive, single-target, motion state extraction algorithm, utilizing the inertia-free scanning characteristics of OPA. From this, the trajectory of the target can be reshaped accurately, and the target motion state can be calculated with an error of less than 3%. The second sub-algorithm is a CS-GI algorithm that requires a small number of samples to achieve a high-resolution OPA-based GI. The sampling ratio employed in the CS-GI algorithm corresponds to the root mean square error (RMSE) convergence of the reconstructed image is 1. The proposed technique for moving target imaging can be effectively used to perform motion trajectory reshaping and image reconstruction of targets undergoing fast and complex motion. We believe that this technique can be effectively used in the fields of vehicle-mounted LiDAR, unmanned systems, and medical imaging.

Digital holographic imaging has emerged as a transformative technology with significant implications for AR/VR devices. However, existing techniques often suffer from limitations such as restricted field of view (FOV), high power consumption, and contrast distortion. This paper introduces an innovative optical phased array (OPA)-based chip, integrating polarization, amplitude, and phase multiplexing for enhanced complex amplitude holographic imaging. A checkerboard-style staggered array is employed in the control strategy, substantially reducing power consumption and enabling the potential for large-scale array integration. To further enhance imaging quality, we introduce what we believe are two novel calibration strategies: one is to achieve super-resolution through block imaging methods, and the other is to image using sparse aperture methods. These advancements not only provide a robust foundation for high-quality holographic imaging, but also present a new paradigm for overcoming the inherent limitations of current active holographic imaging devices. Due to challenges in chip fabrication, the research is primarily simulation-based. Nevertheless, this work presents meaningful advancements in digital holographic imaging for AR/VR applications and provides a foundation for future experimental validations.

A centroid dynamic programming track-before-detect algorithm is proposed, which is applied for tracking the moving target with an unknown speed. Using the inertialess scanning based on an optical phased array, the experimental tracking system is established, and the obtained maximum signal-to-noise ratio is 9.97 dB. Targets of different motion states can be accurately tracked with this algorithm. In addition, we innovated the original track-before-detect algorithm by adding the variable step, so that the target with large accelerations can be tracked accurately. The accuracy of our proposed algorithm is verified numerically and experimentally, which shows that our algorithm can be used to track the target trajectory effectively, and the error in extracting the target velocity is below 2%.