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Diminished Incidence associated with Rib Cracks throughout Expecting a baby People Following Motor Vehicle Crashes.
On-chip controlling of photon spin is essential in developing future integrated nanophotonics with complex functionalities. Here we propose and demonstrate a robust spin-sorting nanocircuit, which consists of a spin-orbit coupler (i.e., combined nanoring and nanodisk) and an L-shaped dielectric-loaded surface plasmon (DLSPs) waveguide. The nanocircuit with optimized geometric parameters is shown to be capable of unidirectionally exciting and routing a DLSP mode along an independent waveguide. We found experimentally that the proposed device possesses an average insertion loss (extinction ratio) of 0.13 dB (14.8 dB) under complete circularly polarized incidence with opposite spin, which is in good agreement with theoretical calculations. The proposed spin-selective scheme may pave the way for applications in the manipulation of chirality with a flexible degree of freedom.Programmable photonic integrated circuits are emerging as an attractive platform for applications such as quantum information processing and artificial neural networks. However, current programmable circuits are limited in scalability by the lack of low-power and low-loss phase shifters in commercial foundries. Here, we demonstrate a compact phase shifter with low-power photonic microelectromechanical system (MEMS) actuation on a silicon photonics foundry platform (IMEC's iSiPP50G). The device attains (2.9π±π) phase shift at 1550 nm, with an insertion loss of (0.33-0.10+0.15)dB, a Vπ of (10.7-1.4+2.2)V, and an Lπ of (17.2-4.3+8.8)µm. We also measured an actuation bandwidth f-3dB of 1.03 MHz in air. We believe that our demonstration of a low-loss and low-power photonic MEMS phase shifter implemented in silicon photonics foundry compatible technology lifts a main roadblock toward the scale-up of programmable photonic integrated circuits.Plasmons have received intensive attention owing to their significant spectrum shift in environmental sensing. Experimentally, the same spectral shifts may be caused by different combinations of structural parameters of a plasmonic nanoparticle. This multi-parameter problem cannot be solved by just a single feature analysis, but requires using the full scattering spectrum containing all features of the parameters. In this Letter, a deep learning method for solving multi-parameter problems is proposed based on the layer refractive index (n) and layer thickness (d) sensing of different nanorods and nanospheres. The full scattering spectrum can be theoretically simulated, precisely predicted using a well-trained deep learning method, and experimentally obtained using a homemade dark-field microscope. An error analysis of the simulation and experimental results indicates that this method is a potential way to determine n and d and further solve multi-parameter in plasmon sensing.The reflection spectra of conventional fiber Bragg gratings (FBGs) with uniform index modulation profiles typically have strong sidelobes, which hamper the performance of FBG-based optical filters, fiber lasers, and sensors. Here, we propose and demonstrate a femtosecond laser line-by-line (LbL) scanning technique for fabricating apodized FBGs with suppressed sidelobes. This approach can flexibly achieve various apodized modulation profiles via precise control over the length and/or transverse position of each laser-inscribed index modification track. We theoretically and experimentally studied the influences of the apodization function on the side-mode suppression ratio (SMSR) in the fabricated apodized FBG, and the results show that a maximum SMSR of 20.6 dB was achieved in a Gaussian-apodized FBG. Subsequently, we used this method to fabricate various apodized FBGs, and the SMSRs in these FBGs were reduced effectively. Specifically, a dense-wavelength-division-multiplexed Gaussian-apodized FBG array with a wavelength interval of 1.50 nm was successfully fabricated, and the SMSR in such an array is 14 dB. Moreover, a Gaussian-apodized phase-shifted FBG and chirped FBG were also demonstrated with a high SMSR of 14 and 16 dB, respectively. Therefore, such an apodization method based on a modified femtosecond laser LbL scanning technique is an effective and flexible way to fabricate various FBGs with high SMSRs, which is promising to improve the performance of optical filters, fiber lasers, and sensors.Millimeter-level resolution through-the-wall radar (TWR) imaging is demonstrated using a broadband nonlinear frequency-modulated (NLFM) signal that is generated by an optically injected semiconductor laser. The proposed system uses period-one dynamics of a semiconductor laser, together with an optical frequency downconversion technique to generate NLFM signals, which addresses the problem of traditional period-one oscillation not being able to generate broadband signals in the low-frequency region. In the experiment, an NLFM signal having a broad bandwidth of 18.5 GHz (1.5-20 GHz) is generated with a corresponding radar range resolution of 8.1 mm. Using this signal, TWR imaging is demonstrated, in which the use of the NLFM signal achieves good side-lobe suppression during pulse compression, and a modified back projection imaging algorithm with sub-aperture weighting is proposed to improve the imaging quality.We report on a 1 kHz, 515 nm laser system, based on a commercially available 230 W average power YbYAG thin-disk regenerative amplifier, developed for pumping one of the last optical parametric chirped pulse amplification (OPCPA) stages of the Allegra laser system at ELI Beamlines. To avoid problems with self-focusing of picosecond pulses, the 1030 nm output pulses are compressed and frequency doubled with an LBO crystal in vacuum. Bak apoptosis Additionally, development of a thermal management system was needed to ensure stable phase matching conditions at high average power. The resulting 515 nm pulses have an energy of more than 120 mJ with SHG efficiency of 60% and an average RMS stability of 1.1% for more than 8 h.We demonstrate an on-chip Yb3+-doped lithium niobate (LN) microdisk laser. The intrinsic quality factors of the fabricated Yb3+-doped LN microdisk resonator are measured up to 3.79×105 at a 976 nm wavelength and 1.1×106 at a 1514 nm wavelength. The multi-mode laser emissions are obtained in a band from 1020 to 1070 nm pumped by a 984 nm laser and with the low threshold of 103µW, resulting in a slope efficiency of 0.53% at room temperature. Furthermore, both the second-harmonic frequency of pump light and the sum frequency of the pump light and laser emissions are generated in the on-chip Yb3+-doped LN microdisk, benefiting from the strong χ(2) nonlinearity of LN. These microdisk lasers are expected to contribute to the high-density integration of a lithium niobate on insulator-based photonic chip.We propose and demonstrate an orbital angular momentum (OAM) fiber amplifier supporting 14 OAM modes based on a fabricated ring-core erbium-doped fiber (RC-EDF) with a tailored erbium-doped profile. Theoretical analyses and numerical simulations suggest that the proposed RC-EDF provides relatively uniform gain larger than 20 dB for all 14 modes. With a core pump configuration, we experimentally characterize the performance of the RC-EDF-assisted OAM fiber amplifier, which can acquire a high modal gain up to 33.4 dB and low differential modal gain less than 1.8 dB at the wavelength of 1550 nm. The obtained results indicate successful implementation of the RC-EDF-assisted OAM fiber amplifier for 14 OAM modes with favorable performance.Phase-difference sensing technology (PDST) has been applied to strain measurement, but its completeness is destroyed by the phase-difference measurement range. A scheme that can realize the completeness of the PDST for low-frequency strain interrogation is proposed. It is built on dual-interferometers and the elliptic-fitting algorithm. To break the measurement range limitation (0, π), a phase compensation setting is applied. The experimental results demonstrate that the method can obtain low-frequency strain signals, and the low-frequency signal whose phase amplitude is greater than π is recovered. The scheme is an efficient and complete method for measuring the strain of low-frequency optical fiber length, which could be applied to low-frequency seismic wave monitoring and rock deformation detection.In this work, the novel, to the best of our knowledge, blue-cyan Y2Mg0.8Sr0.2Al4SiO12Eu2+ (YM0.8S0.2ASEu2+) phosphors were synthesized by the solid-state method. At 150°C, the emission intensity of Y2Mg0.8Sr0.2Al4SiO120.005Eu2+ can retain 96.38% of the relative intensity, which means that this phosphor shows high thermal stability. A white light-emitting diode (LED) device is fabricated by combining a 370 nm near ultraviolet LED chip and commercial phosphors (green, (Ba,Sr)2SiO4Eu; red, CaSiAlN3Eu). The white LED has an excellent property with the correlated color temperature CCT=5236K and superhigh color rendering index Ra=96.1, which indicates the potential application in white LED fields.To realize multimodal hemodynamic imaging, pulse photothermal optical coherence tomography (P-PTOCT) is proposed in this Letter to solve the separation problem of photothermal phase and Doppler phase, which is difficult to solve in traditional PTOCT. This technique can obtain blood flow distribution, light absorption distribution, and concentration images simultaneously. Based on the difference between pulse photothermal phase and Doppler phase, we propose an even number differential demodulation algorithm that can separate the photothermal phase and Doppler phase from the same scanning data set. The separated photothermal phase can characterize the trend of drug concentration, which provides the possibility for quantitative measurement of plasma concentration. The combination of photothermal phase and Doppler phase is helpful for potential clinical research on hemodynamics of cerebral ischemia and provides a technical reference for the rapid acquisition of perfusion volume and plasma concentration at one time.We propose a geometric optimization method combined with the Coulombic energy indicator that can uniformly distribute N polarization states on the Poincaré sphere. Based on this method, we investigate the optimal frames of a rotating polarizer and rotating quarter-wave plate (RPRQ)-based polarization state generator (PSG) at different numbers of modulations. We use the PSG on a dual DoFP polarimeter-based Mueller matrix microscope to measure standard samples and pathological sections for testing the performance of an optimized RPRQ. The experimental results show that this method can effectively restrain noise and improve measurement accuracy.A time magnifier based on space-time duality has demonstrated comprehensive applications owing to its promising temporal resolution. However, conventional parametric time magnifiers are inherently polarization-sensitive; their output intensity depends not only on the intensity but also the polarization of signal under test (SUT). Therefore, they are mainly applied to SUT with fixed polarization. On the other hand, many complex optical signals exhibit simultaneous intensity and polarization dynamics. In this Letter, a polarization-independent (PI) time magnifier at 485-fs temporal resolution is first demonstrated, which provides accurate intensity information even for polarization-related signals. The PI time magnifier de-convolves intensity and polarization information. It, therefore, paves the way for in-depth analysis of various complex ultrafast phenomena involving simultaneous intensity and polarization dynamics such as rogue waves and vector solitons.
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