
- Jun. 11, 2025
- Vol. , Issue (2025)
- Jun. 11, 2025
- Vol. , Issue (2025)
- Jun. 11, 2025
- Vol. , Issue (2025)
- Jun. 10, 2025
- Vol. 13, Issue 1 (2025)
- Jun. 10, 2025
- Vol. 13, Issue 4 (2025)
Photoacoustic microscopy (PAM) operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biologi
Photoacoustic microscopy (PAM) operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues. Despite its potential, the effectiveness of lipid-based PAM has been limited by the performance of existing nanosecond laser sources at this wavelength. In this work, we introduce a 1725-nm hybrid optical parametric oscillator emitter (HOPE) characterized by a narrow bandwidth of 1.4 nm, an optical signal-to-noise ratio (OSNR) of approximately 34 dB, and a high spectral energy density of up to 480 nJ/nm. This advanced laser source significantly enhances the sensitivity of photoacoustic imaging, allowing for the detailed visualization of intrahepatic lipid distributions with an impressive maximal contrast ratio of 23.6:1. Additionally, through segmentation-based analysis of PAM images, we were able to determine steatosis levels that align with clinical assessments, thereby demonstrating the potential of our system for high-contrast, label-free lipid quantification. Our findings suggest that the proposed 1725-nm HOPE source could be a powerful tool for biomedical research and clinical diagnostics, offering a substantial improvement over current technologies in the accurate and non-invasive assessment of lipid accumulation in tissues.show less
- Jun.13,2025
- Photonics Research,Vol. 13, Issue 7
- 1810 (2025)
Chronic diabetic wounds, a common and severe complication of diabetes, are characterized by their inability to heal due to impaired blood and oxygen suppl
Chronic diabetic wounds, a common and severe complication of diabetes, are characterized by their inability to heal due to impaired blood and oxygen supply. In addition to glycemic control, various clinical treatments such as wound dressings, hyperbaric oxygen therapy, and phototherapy have been employed to manage these wounds. Low-level light therapy has emerged as an effective, noninvasive, and painless therapeutic approach for wound management. However, the bulkiness of traditional light sources and the need for frequent clinic visits have limited its widespread adoption. We have developed a wearable, flexible light-emitting bandage with cyanobacterial impregnation (LEB@Cyan). The bioactive bandage is designed to provide sustained oxygen generation and robust photobiomodulation, promoting keratinocyte migration, fibroblast proliferation, and angiogenesis. This addresses the hypoxic conditions and enhances bioenergetic supply to accelerate the healing process of diabetic wounds. In detail, the wound area of diabetic rats treated with LEB@Cyan showed significant reductions of 74.76% and 96.32% compared with that of LEB-treated diabetic rats and untreated diabetic rats, respectively. Such self-oxygenated wearable light-emitting fabric holds great promise for future clinical and commercial applications, potentially revolutionizing the management of chronic diabetic wounds.show less
- Jun.13,2025
- Advanced Photonics Nexus,Vol. 4, Issue 4
- 046005 (2025)
Metasurface modeling, designs, and applications using computational approaches are by now well established as an essential pillar in photonics, physics, a
Metasurface modeling, designs, and applications using computational approaches are by now well established as an essential pillar in photonics, physics, and materials science. The past years have witnessed tremendous advances in methodologies and technologies to unearth the intricate light–matter interaction and promote adaptive metadevices. They have pushed the studies of metasurfaces from early passive, reconfigurable modalities to the next generation of intelligent metasurfaces. In this review, we elaborate general architecture for intelligent metasurfaces, constructed by the algorithm layer, tunable metasurface layer, and application layer. We first discuss a variety of deep learning models, ranging from the fundamental neural networks inspired by computer science to sophisticated algorithms embedded with physical specialty, highlighting their potential in the forward prediction, inverse design, and spectral correlation of metasurfaces. We then discuss adaptive metadevices in the main applications of invisibility cloaks, smart vision, intelligent sensing, and wireless communication. Finally, we pinpoint current challenges and future perspectives to embrace the coming era of intelligent metasurfaces.show less
- Jun.13,2025
- Advanced Photonics,Vol. 7, Issue 3
- 034005 (2025)
Electric field poling of electro-optic polymer (EOP) in hybrid waveguides is highly challenging due to the discontinuity in electric field distribution, w
Electric field poling of electro-optic polymer (EOP) in hybrid waveguides is highly challenging due to the discontinuity in electric field distribution, which leads to a low Pockels electro-optic (EO) coefficient or dielectric breakdown. We propose the segmented poling technique in Si3N4/EOP hybrid waveguides to address this challenge. Dipolar chromophores near an electrode interface first align with a weak poling electric field, and then a strong field is applied for the chromophore alignment near the waveguide interface. This technique effectively avoids dielectric breakdown, and the tuning efficiency of the EO Mach–Zender interferometer (MZI) filters is improved from 31.7 pm/V to higher than 50 pm/V, with a highest Pockels coefficient of 114 pm/V.show less
- Jun.13,2025
- Chinese Optics Letters,Vol. 23, Issue 7
- 071301 (2025)
Spatiotemporal mode-locked (STML) fiber lasers have emerged as a novel platform for investigating spatiotemporal solitons and three-dimensional nonlinear phenomena. In this work, we report the g
Spatiotemporal mode-locked (STML) fiber lasers have emerged as a novel platform for investigating spatiotemporal solitons and three-dimensional nonlinear phenomena. In this work, we report the generation of synchronous dual-wavelength STML noise-like square pulses in a few-mode fiber laser, characterized by distinct pulse durations at each wavelength. To further explore the experimental results, numerically simulations are conducted, where the mode-related and wavelength-related characteristics of the dual-wavelength noise-like pulses are revealed. It is found that different modes have distinct transient time-frequency characteristics, and a broader spectrum correlates with a longer duration of the pulse envelop and shorter duration of the sub-pulses. Additionally, the mode components of the pulses at different wavelengths play a supportive role in facilitating the synchronization of the two wavelengths. These findings enhance our understanding of the underlying mechanisms and characteristics of noise-like pulses in STML fiber lasers and exploration their potential applications.show less
- Jun.13,2025
- Chinese Optics Letters,Vol. 23, Issue 9
- (2025)
This study investigates the effects of laser off-nadir angle on sea surface echo dynamic range in airborne oceanic lidar. Using a dual-wavelength (486/532 nm) system with fixed off-nadir angles,
This study investigates the effects of laser off-nadir angle on sea surface echo dynamic range in airborne oceanic lidar. Using a dual-wavelength (486/532 nm) system with fixed off-nadir angles, varied aircraft rolls generated adjustable water-incident angles. Two-three order-of-magnitude sea surface signal variations at 0° – 35° off-nadir angles are revealed. A range of experimental results have shown that when the aircraft is at a lower altitude, saturation occurs at 0° – 10° but is avoided at 15° – 35°. Comparisons with simulations confirm that optimizing off-nadir angles reduces dynamic range occupancy and prevents saturation of sea surface signals, enhancing lidar performance in oceanic profiling.show less
- Jun.12,2025
- Chinese Optics Letters,Vol. 23, Issue 11
- (2025)
Digital micromirror devices (DMDs) have emerged as essential spatial light modulators for holographic 3D near-eye displays due to their rapid refresh rates and precise wavefront modulation chara
Digital micromirror devices (DMDs) have emerged as essential spatial light modulators for holographic 3D near-eye displays due to their rapid refresh rates and precise wavefront modulation characteristics. However, since the modulation depth of DMDs is limited to binary levels, the quality of reproduced image from binary computer-generated hologram (CGH) is often deficient. In this paper, we propose a stochastic gradient descent (SGD) based binary CGH optimization framework where a convolutional neural network (CNN) is employed to perform the differentiable hologram binarization operation. The CNN based binary SGD optimization can significantly minimize the binary quantization noise in the generation of binary CGH, providing superior and high-fidelity holographic display. Our proposed method is experimentally verified by displaying both of high-quality 2D and true 3D images from optimized binary CGHs.show less
- Jun.10,2025
- Chinese Optics Letters,Vol. 23, Issue 10
- (2025)
This study proposes a dual-parameter sensor to simultaneously measure curvature and temperature using a 3D printed seven-core optical fiber inscribed with a fiber Bragg grating (FBG). The seven-
This study proposes a dual-parameter sensor to simultaneously measure curvature and temperature using a 3D printed seven-core optical fiber inscribed with a fiber Bragg grating (FBG). The seven-core fiber used was prepared by 3D printing fiber technology of great flexibility in both structure and material. Attributed to the asymmetrical structure of this 3D printed fiber, the sensor is capable of distinguishing the bending directions. Furthermore, the sensing characteristics and the directional recognition mechanism of the sensor are analyzed through both theoretical simulations and experimental investigations. The proposed sensor incorporates two sensing elements, specifically the Mach-Zehnder interferometer (MZI) and FBG. The combination of the MZI and FBG in the sensor enables simultaneous measurement of curvature and temperature. This vector sensor has a sensitivity of 25.782 nm/m-1 in the curvature range of 0.000-1.518 m-1, when the bending is applied along the defined direction of 30°. Within the temperature range of 20.0-110.0 ℃, the temperature sensitivity is 34 pm/℃. Experimental results validate the excellent performance of the proposed sensor, providing an efficient and scalable solution for dual-parameter sensing in future industrial and environmental applications.show less
- Jun.09,2025
- Chinese Optics Letters,Vol. 23, Issue 10
- (2025)
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- Jun. 09, 2025
- Journal
- Jun. 09, 2025