Once dismissed as a drawback in optical processing, low coherence of light is now gaining renewed attention, as recent studies reveal that harnessing optic

Once dismissed as a drawback in optical processing, low coherence of light is now gaining renewed attention, as recent studies reveal that harnessing optical coherence can unlock enhanced capabilities in information processing. Despite ongoing efforts, a persistent challenge remains: the coherence of light degrades significantly under beam propagation, causing information loss and limiting the feasibility of secure remote transmission. This work presents a coherence-weight-based scheme for remote image transport where the confidential image is encoded into the coherence weights of a partially coherent beam whose statistical structure is preserved during free-space propagation. At the receiver, the original image is successfully reconstructed from the characteristic function—cross-spectral density function of the transmitted beam. Furthermore, the image remote transport scheme demonstrates strong robustness against the opaque obstacles during transmission, with experimental results showing high fidelity and a similarity index exceeding 90%. Exploiting the coherence weight of light as an advanced tool for target information manipulation broadens its applications and opens new avenues in high-security optical communication, holography, and image-based computing.show less

Chaotic microcavities play a crucial role in several research areas, including the study of unidirectional microlasers, nonlinear optics, sensing, quantum

Chaotic microcavities play a crucial role in several research areas, including the study of unidirectional microlasers, nonlinear optics, sensing, quantum chaos, and non-Hermitian physics. To date, most theoretical and experimental explorations have focused on two-dimensional (2D) chaotic dielectric microcavities, but there have been minimal studies on three-dimensional (3D) ones because precise geometrical information of a 3D microcavity can be difficult to obtain. Here, we image 3D microcavities with submicron resolution using X-ray microcomputed tomography (μCT), enabling nondestructive imaging that preserves the sample for subsequent use. By analyzing the ray dynamics of a typical deformed microsphere, we demonstrate that a sufficient deformation along all three dimensions can lead to chaotic ray trajectories over extended time scales. Notably, using the X-ray μCT reconstruction results, the phase space chaotic ray dynamics of a deformed microsphere are accurately established. X-ray μCT could become a unique platform for the characterization of such deformed 3D microcavities by providing a precise means for determining the degree of deformation necessary for potential applications in ray chaos and quantum chaos.show less

Spectroscopy has become an effective detection tool in fields such as environmental monitoring, food safety, and public health. Terahertz time-domain spect

Spectroscopy has become an effective detection tool in fields such as environmental monitoring, food safety, and public health. Terahertz time-domain spectroscopy (THz-TDS) is notable for its label-free and nondestructive evaluation capabilities, as well as its ability to extract material properties such as dielectric constants and absorption coefficients. However, the intrinsic damping of molecular materials significantly limits the sensitivity of THz-TDS in detecting trace molecules. In our study, we utilized a THz-TDS system to measure the terahertz spectra of water vapor molecules at varying interaction distances (d). By employing synthetic complex-frequency wave (CFW) excitation, virtual gain was introduced to counterbalance the intrinsic damping of water vapor molecules, thereby enhancing the sensitivity of terahertz detection. Experimental results show that applying synthetic CFW excitation to spectral responses containing phase information notably improves the detection sensitivity of water vapor molecules’ absorption features in the terahertz range at two distinct interaction distances (d). Synthetic CFW excitation amplifies molecular vibrational fingerprint signals within the terahertz range, expanding the potential applications of THz-TDS in fields such as molecular identification, pharmaceutical analysis, and carrier dynamics in semiconductors.show less

A color-incoherent Fourier ptychography method that uses polarization to encode wavelength information is proposed. Conventional incoherent Fourier ptychog

A color-incoherent Fourier ptychography method that uses polarization to encode wavelength information is proposed. Conventional incoherent Fourier ptychography achieves monochromatic imaging beyond the diffraction limit through structured illumination and computational reconstruction. In the proposed method, wavelength information is encoded by a polarized-type divided aperture color-coding unit, resulting in a set of low-resolution images for each wavelength corresponding to the illumination patterns. The proposed approach is validated through numerical simulations and optical experiments. The results confirm that the method enables color imaging beyond the diffraction limit.show less