Using our novel microfluidic device-integrated deep-UV microscopy, we determined absolute neutrophil counts (ANC) showing strong correlation with commercial CBC results in patients with moderate to severe neutropenia and healthy donors. This investigation provides the theoretical underpinnings for a compact, easy-to-use UV microscope system, designed for monitoring neutrophil counts in resource-constrained settings, at home, or at the point of care.
Our atomic-vapor-based imaging method enables a rapid readout of terahertz orbital angular momentum (OAM) beams. Utilizing phase-only transmission plates, OAM modes incorporating azimuthal and radial indices are formed. Using an optical CCD camera, the beams' far-field image is captured, after undergoing terahertz-to-optical conversion inside an atomic vapor. Not only the spatial intensity profile, but also the self-interferogram of the beams, captured by imaging through a tilted lens, enables a direct determination of the sign and magnitude of the azimuthal index. This approach guarantees accurate and consistent determination of the OAM mode from low-intensity beams with high fidelity in 10 milliseconds. The implications of this demonstration are foreseen to be profound and widespread, impacting future applications of terahertz OAM beams for communication and microscopy technologies.
An aperiodically poled lithium niobate (APPLN) chip, employing aperiodic optical superlattice (AOS) technology for its domain structure, is instrumental in the demonstration of an electro-optic (EO) switchable Nd:YVO4 laser that emits dual wavelengths at 1064 nm and 1342 nm. Through voltage-driven adjustments, the APPLN, a wavelength-sensitive electro-optic polarization controller, enables selection amongst multiple laser spectral emissions within the polarization-dependent amplification system. By driving the APPLN device with a voltage-pulse train that shifts between VHQ, enabling gain in target laser lines, and VLQ, suppressing gain in laser lines, a unique laser system generates Q-switched laser pulses at dual wavelengths (1064 and 1342 nm), single-wavelength (1064 nm), and single-wavelength (1342 nm), as well as their non-phase-matched sum-frequency and second-harmonic generations at VHQ=0, 267, and 895 volts, respectively. Technical Aspects of Cell Biology A laser can benefit, to our knowledge, from a novel simultaneous EO spectral switching and Q-switching mechanism, thereby accelerating its processing speed and improving its multiplexing capacity for use in a variety of applications.
By exploiting the unique spiral phase structure of twisted light, we exhibit a picometer-scale, real-time interferometer that effectively cancels noise. We employ a solitary cylindrical interference lens to construct the twisted interferometer, enabling concurrent measurements on N phase-orthogonal single-pixel intensity pairs selected from the petals of the daisy-like interference pattern. A significant three orders of magnitude reduction in noise, compared to a single-pixel detection approach, was instrumental in our setup's ability to achieve sub-100 picometer resolution in real-time measurements of non-repetitive intracavity dynamic events. The noise-cancellation performance of the twisted interferometer exhibits a statistical growth with increasing values of the radial and azimuthal quantum numbers of the twisted light. The proposed scheme has potential applications in both precision metrology and the development of analogous concepts for twisted acoustic beams, electron beams, and matter waves.
A novel, as far as we are aware, coaxial double-clad-fiber (DCF) and graded-index (GRIN) fiberoptic Raman probe is reported to improve the efficacy of in vivo Raman measurements of epithelial tissue. An ultra-thin DCF-GRIN fiberoptic Raman probe with a 140-meter outer diameter is constructed using a highly efficient coaxial optical configuration. This configuration, achieved by splicing a GRIN fiber onto the DCF, optimizes excitation/collection efficiency and depth-resolved selectivity. In vivo Raman spectral acquisition from various oral tissues (buccal, labial, gingiva, mouth floor, palate, and tongue) using the DCF-GRIN Raman probe yields high-quality results, encompassing both the fingerprint (800-1800 cm-1) and high-wavenumber (2800-3600cm-1) regions, all achieved within sub-second acquisition times. The high sensitivity with which biochemical differences between different epithelial tissues in the oral cavity can be detected suggests the DCF-GRIN fiberoptic Raman probe's potential for in vivo diagnosis and characterization of epithelial tissue.
Organic nonlinear optical crystals are particularly effective (>1%) in generating terahertz (THz) radiation. Using organic NLO crystals presents a challenge due to the unique THz absorptions in each crystal, impeding the achievement of a powerful, smooth, and broad emission spectrum. read more Employing THz pulses originating from the complementary crystals DAST and PNPA, this work seamlessly fills spectral gaps, culminating in a uniform spectrum extending up to 5 THz. The peak-to-peak field strength, a consequence of combined pulses, expands its range from a baseline of 1 MV/cm to an elevated 19 MV/cm.
Traditional electronic computing systems heavily rely on cascaded operations to implement sophisticated strategies. In all-optical spatial analog computing, we now introduce cascaded operations. The first-order operation, with its singular function, faces difficulties in meeting the needs of practical image recognition applications. By cascading two first-order differential units, all-optical second-order spatial differentiators are produced, and their ability to detect image edges in both amplitude and phase is exemplified. Our model suggests a practical approach to the creation of compact, multifunctional differentiation elements and high-performance optical analog computing frameworks.
Through experimental demonstration, we propose a simple and energy-efficient photonic convolutional accelerator based on a monolithically integrated multi-wavelength distributed feedback semiconductor laser, which utilizes a superimposed sampled Bragg grating structure. The 4448 GOPS photonic convolutional accelerator, incorporating a 22-kernel structure with a 2-pixel vertical stride for the convolutional window, is capable of real-time image recognition processing, generating 100 images. Furthermore, a real-time prediction accuracy of 84% is achieved for handwritten digits on the MNIST database. This work explores a compact and low-cost technique for the execution of photonic convolutional neural networks.
A BaGa4Se7 crystal forms the basis for the first tunable femtosecond mid-infrared optical parametric amplifier, which is distinguished by its ultra-broadband spectral range. Leveraging the broad transparency range, high nonlinearity, and relatively large bandgap of BGSe, the MIR OPA, operating at 1030nm with a 50 kHz repetition rate, displays an output spectrum that is tunable across a remarkably extensive spectral range spanning from 3.7 to 17 micrometers. The MIR laser source, at a central wavelength of 16 meters, registers a maximum output power of 10mW, which equates to a quantum conversion efficiency of 5%. A robust pump, coupled with a substantial aperture dimension, is the key to straightforward power scaling in BGSe. The BGSe OPA has the capacity to support a pulse width of 290 femtoseconds, precisely centered at 16 meters. The results of our experiments suggest that BGSe crystal can be considered a prospective nonlinear crystal for the generation of fs MIR light, characterized by an exceptionally broad tunable spectral range via parametric downconversion, thus enabling a wide range of applications, including MIR ultrafast spectroscopy.
In the realm of terahertz (THz) technology, liquids appear to be a noteworthy area of exploration. Nonetheless, the measured THz electric field is restricted by the effectiveness of data collection and the phenomenon of saturation. A simplified simulation, factoring in the interference of ponderomotive-force-induced dipoles, reveals that plasma reshaping concentrates THz radiation along the collection axis. Using a dual cylindrical lens system, a linearly shaped plasma was generated in the transverse plane, leading to the redirection of THz radiation. The dependence of the pump energy exhibits a quadratic behavior, signifying a significant attenuation of the saturation effect. surface immunogenic protein The THz energy, as a consequence, has been augmented by a factor of five. This demonstration presents a simple, but highly efficient, method for further increasing the range of detectable THz signals originating from liquid samples.
Lensless holographic imaging finds a highly competitive solution in multi-wavelength phase retrieval, which is highlighted by an economical, compact design, and fast data acquisition. Still, the presence of phase wraps presents a distinct challenge to iterative reconstruction, resulting in algorithms that often lack broad applicability and entail heightened computational complexity. For multi-wavelength phase retrieval, we advocate a projected refractive index framework that directly recovers the object's amplitude and its unwrapped phase. The forward model incorporates and linearizes general assumptions. By means of an inverse problem formulation, physical constraints and sparsity priors are utilized, ensuring the quality of images obtained from noisy measurements. A high-quality quantitative phase imaging system, based on a lensless on-chip holographic imaging system with three color LEDs, is experimentally demonstrated.
A new, long-lasting fiber grating configuration is introduced and successfully tested. Micro air channels are integral to the device's structural design, which utilizes a single-mode fiber. The fabrication process entails employing a femtosecond laser to inscribe multiple groups of fiber inner waveguide arrays, followed by the meticulous application of hydrofluoric acid etching. Only five grating periods constitute the 600-meter long-period fiber grating. We believe this reported long-period fiber grating has the shortest length. In the refractive index range of 134-1365, the device displays a significant refractive index sensitivity of 58708 nm/RIU (refractive index unit), while the temperature sensitivity is comparatively small at 121 pm/°C, minimizing temperature cross-sensitivity.