物理与天体物理最新文献

Miniaturized lenses with a large depth of field and high imaging quality are desirable for compact optical systems, as they eliminate the need for lens switching and repeated refocusing. Metalenses, composed of flat, subwavelength nanostructures, are well suited to this demand due to their ultra-thin profile and design flexibility. However, miniaturized metalenses typically require larger numerical apertures (NA), which lead to strong chromatic dispersion and resolution degradation. To address this limitation, we propose a Metalens Depth-of-Field Generative Adversarial Network tailored for restoring full-color images captured by a high-NA (0.447) millimeter-scale metalens. It achieves a 35% increase in peak signal-to-noise ratio and a 57.7% reduction in perceptual loss, while maintaining reconstruction quality across over 17.5 cm depth of field without additional training. This network provides a practical and scalable solution for enhancing image quality in miniaturized imaging systems.

Large Sagnac interferometers in the form of active ring lasers have emerged as unique rotation sensors in the geosciences, where their sensitivity allows one to detect geodetic and seismological signals. The passive laser gyroscope variant, however, is still at a stage of development, and thus far, only the Pound-Drever-Hall frequency stabilization technique has been explored, a method limited by residual amplitude modulation. Here, as an alternative method, we present the first Hänsch-Couillaud locked passive laser gyroscope. We find that this method is limited by flicker noise, and we introduce a cost-effective lock-in scheme to overcome this limitation. We achieve a sensitivity of 3.1nrad/s, corresponding to a fraction of 7.7×10^-5 in the Earth's rotation rate.

Wavefront manipulation and correction using feedback-based optimization have long been employed in optical applications such as microscopy, optical sensing, astronomical imaging, and communication. With recent advances in quantum optics, wavefront correction has become a crucial tool in quantum imaging, quantum communication, and efficient photon coupling. Consequently, understanding the performance of optimization algorithms under low-photon conditions is essential for the effective deployment of quantum optical systems. This study investigates the performance of two algorithms in the photon-counting regime across varying mean photon rates through experiments and numerical simulations. Furthermore, we propose, simulate, and implement a novel, to the best of our knowledge, augmented algorithm that combines the strengths of both methods and is particularly well suited for quantum applications.

Optical crosstalk plays a key role in degrading the color accuracy and contrast of GaN-based micro-light emitting diodes (micro-LEDs) in display applications, and a comprehensive solution to this issue remains elusive. In this Letter, we propose a micro-LED array structure featuring individual pixels surrounded by a circular wall deposited with silver (Ag) as a reflective medium, and the effect of crosstalk reduction is well demonstrated. Compared to the conventional micro-LED devices, the luminous intensity distribution mapping indicated that the proposed micro-LED structure achieves a significant light spot reduction under the injection current of about 0.5 mA, and a low-crosstalk display is achieved through a 16 × 16 array. Furthermore, the optical field distribution of the proposed micro-LED structure was studied based on finite-difference time-domain (FDTD) simulation. The results reveal that when the height and gap width of the reflective wall are 5 µm respectively, more than 55% of the light emission is effectively limited within the ±45^∘ divergence angle. This work presents a promising solution for mitigating optical crosstalk in micro-LED displays, thereby enhancing their performance for high-quality display applications.

Quasi-periodicity has numerous applications in various fields, such as the discovery and study of quasicrystals. In the region of manipulating vector optical fields (VOFs), the periodicity is very common, but the quasi-periodicity is rarely seen. Here, we propose a kind of two-dimensional quasi-periodic VOF, introducing the concept of quasi-periodicity into the region of manipulating VOFs. We then study the optical information encoding and transmission. It is demonstrated that the information can be accurately recovered even when up to 75% of the spectrum is obstructed by sector-shaped obstacle. The information remains highly robust under random interference affecting 90% of the wave front during propagation. This work demonstrates the convolution-based construction scheme of the quasi-periodic VOF, along with the explicit information-encoding protocol and experimental demonstration. The quasi-periodic VOF opens an avenue for robust optical information transmission over long-distances.