Notes

Visual tiredness caused by simply watching personal actuality unit and the effects regarding anisometropia.
To the best of our knowledge, we report here the first demonstration of 2.9 µm laser emission from in-house fabricated Ho3+/Pr3+ co-doped ZBYA glass fiber. The fiber was fabricated based on the ZBYA glass with compositions of ZrF4-BaF2-YF3-AlF3-PbF2-HoF3-PrF3. Under the pump of a 1150 nm Raman fiber laser, the maximum unsaturated output power of 2.16 W was obtained in a 15 cm long gain fiber with a slope efficiency of 24%. The influence of rare-earth doping concentration on laser performance was also investigated. The result indicates that ZBYA glass fibers have potential for using as a fluorozirconate glass gain fiber for mid-infrared fiber lasers.The two-dimensional continuous wavelet transform (2D CWT) has been widely used in single-shot fringe projection profilometry (FPP) because of its multi-resolution characteristics and anti-noise ability. This Letter aims to develop a novel 2D wavelet transform model in FPP. Dual-angle rotation operation on a 2D wavelet is performed to improve the directional selectivity and frequency localization of the wavelet. The proposed method improves the accuracy of the phase calculation of wavelet transform profilometry (WTP) for higher accuracy reconstruction from the single-shot fringe. We present mathematical expressions, theoretical analysis, and the comparison to traditional 2D WTP. The experiments demonstrate the effectiveness of the proposed method.We show that a two-dimensional hydrodynamics model provides a physical explanation for the splitting of higher-charge optical vortices under elliptical deformations. The model is applicable to laser light and quantum fluids alike. The study delineates vortex breakups from vortex unions under different forms of asymmetry in the beam, and it is also applied to explain the motion of intact higher-charge vortices.Spectral and temporal mode matching are required for the efficient interaction of photons and quantum memories. In our previous work [Opt. Lett.45, 5688 (2020).10.1364/OL.404891], we proposed a new route to spectrally compress broadband photons to achieve spectral mode matching with narrowband memories, using a linear, time-variant optical cavity based on rapid switching of input coupling. In this work, we extend our approach to attain temporal mode matching as well by exploiting the time variation of output coupling of the cavity. We numerically analyze the mode matching and loss performance of our time-varying cavity and present a possible implementation in integrated photonics.We present an open-source eigenmode expansion (EME) software package entirely implemented in the Python programming language. Eigenmode expansion Python (EMEPy) utilizes artificial neural networks to reproduce electromagnetic eigenmode field profiles to accelerate the EME process by a factor of 3. EMEPy provides an intuitive scripting interface, is easily compatible with a number of other Python packages, and is useful for educators and new designers.Dual-frequency comb spectroscopy permits broadband precision spectroscopy with high acquisition rate. The combs' repetition rates as well as the mutual coherence between the combs are key to fast and broadband measurements. Here, we demonstrate a 1-GHz high-repetition-rate dual-comb system with high mutual coherence (sub-Hz heterodyne beatnotes) based on mature, digitally controlled, low-noise erbium-doped mode-locked lasers. Two spectroscopy experiments are performed with acquisition parameters not attainable in a 100-MHz system detection of water vapor absorption around 1375 nm, illustrating the potential for fast and ambiguity-free broadband operation, as well as acquisition of narrow gas absorption features across a spectral span of 0.6 THz (600 comb lines) in only 5 μs.Bessel beams, with their non-diffractive property, have attracted great interest in recent years. Optical needle shaping of Bessel beams is highly desired in many applications, however, this typically requires low numerical aperture (NA) bulky 4f confocal systems incorporated with spatial light modulators or round filters. Here, we employ a circular dielectric metagrating for perfect Bessel beam transformation at a desired wavelength. learn more The dielectric metagrating exhibits a high transmissive diffraction efficiency (up to 75%) for a broadband (460 nm to 560 nm), wide-angle range, and dual-polarization response, which is capable of a high-performance transformation of Bessel beams with arbitrary NAs. Our results show potential for special-beam-required applications such as light storage, imaging, and optical manipulation.Hyperspectral (HS) pansharpening, which fuses the HS image with a high spatial resolution panchromatic (PAN) image, provides a good solution to overcome the limitation of HS imaging devices. However, most existing convolutional neural network (CNN)-based methods are hard to understand and lack interpretability due to the black-box design. In this Letter, we propose a multi-level spatial details cross-extraction and injection network (MSCIN) for HS pansharpening, which introduces the mature multi-resolution analysis (MRA) technology to the neural network. Following the general idea of MRA, the proposed MSCIN divides the pansharpening process into details extraction and details injection, in which the missing details and the injection gains are estimated by two specifically designed interpretable sub-networks. Experimental results on two widely used datasets demonstrate the superiority of the proposed method.Glass is important as a substrate for coatings in a wide range of applications or as a substrate for the fabrication of optical micro/nano structures. Coating by wet chemistry methods often demands modifications of the glass surface properties involving several steps. In addition, the micro/nano structuring is usually a several-step process. New methods that are simpler and more efficient are being proposed. One of them is glass poling that has been used to obtain surface relief on glass and, together with electric field assisted dissolution, for metal nanostructures in glass/metal systems. In this work, we demonstrate that poling increases the susceptibility of the glass surface for coating with Ag nanoparticles synthesized in situ by silver salt reduction. It is shown that a selectively poled glass surface can be used as a template to obtain optical microstructures consisting of Ag nanoparticles in only three simple steps. As a proof-of-concept, the method is used to fabricate diffraction gratings with an optical response that can be tuned by adjusting the Ag concentration. This approach is more versatile than the standard structuring by electric field assisted dissolution, as it does not require application of an elevated temperature once the coating is formed, which might change or destroy the properties of the thermally sensitive coating species or morphologies.An all-optical realization scheme of electromagnetically induced transparency (EIT) in a single silicon optomechanical microring resonator is proposed and demonstrated. Due to the strong mechanical Kerr effect and well-designed microring resonator, two modes with a resonant frequency separation of 292 GHz (2.35 nm) can be tuned into resonance when the control power is about 4.3 µW, and the EIT spectrum is achieved. Our work provides a constructive solution for realizing EIT in a single microcavity with a low mode density. Furthermore, this device is fully integrated on-chip and compatible with current complementary metal-oxide semiconductor (CMOS) processing and has great potential in applications such as light storage, optical sensing, and quantum optics.A compact and robust all-solid-state mid-infrared (MIR) laser at 6.45 µm with high average output power and near-Gaussian beam quality is demonstrated. A maximum output power of 1.53 W with a pulse width of approximately 42 ns at 10 kHz is achieved using a ZnGeP2 (ZGP) optical parametric oscillator (OPO). This is the highest average power at 6.45 µm of any all-solid-state laser to the best of our knowledge. The average beam quality factor is measured to be M2 = 1.19. Moreover, high output power stability is confirmed, with a power fluctuation of less than 1.35% rms over 2 h, and the laser can run efficiently for more than 500 h in total. Using this 6.45 µm pulse as a radiation source, ablation of animal brain tissue is tested. Furthermore, the collateral damage effect is theoretically analyzed for the first time, to the best of our knowledge, and the results indicate that this MIR laser has excellent ablation ability, making it a potential replacement for free electron lasers.We demonstrate an automatic target recognition (ATR) scheme based on an improved photonic time-stretched coherent radar (PTS-CR). The reception apertures of the PTS-CR can cover the entire detection range by receiving the echo signal with high repetition rate pulses and increasing the amount of dispersion of the first dispersive medium in the receiver. Two channels with different stretching factors are simultaneously used to restore the signal delay information. Simulated and experimental results verify the feasibility of the new scheme. Finally, based on the improved receiving scheme, PTS-CR successfully performed ATR on four different targets placed on a rotating stage. Combining this with the training of the convolutional neural network (CNN), the recognition accuracy rate is 94.375%.We report the development of a simple and sensitive two-beam hybrid femtosecond/picosecond pure rotational coherent anti-Stokes Raman scattering (fs/ps CARS) method to simultaneously measure the rotational and vibrational temperatures of diatomic molecules. Rotation-vibration non-equilibrium plays a key role in the chemistry and thermalization in low-temperature plasmas as well as thermal loading of hypersonic vehicles. This approach uses time-domain interferences between ground state and vibrationally excited N2 molecules to intentionally induce coherence beating that leads to apparent non-Boltzmann distributions in the pure rotational spectra. These distortions enable simultaneous inference of both the rotational and vibrational temperatures. Coherence beating effects were observed in single-shot fs/ps CARS measurements of a 75 Torr N2 DC glow discharge and were successfully modeled for rotational and vibrational temperature extraction. We show that this method can be more sensitive than a pure rotational fs/ps CARS approach using a spectrally narrow probe pulse. Lastly, we experimentally measured the beat frequencies via Fourier transform of the time-domain response and obtained excellent agreement with the model.To understand the dynamics of tissue stiffness during neural tube formation and closure in a murine model, we have developed a multimodal, coaligned imaging system combining optical coherence tomography (OCT) and Brillouin microscopy. Brillouin microscopy can map the longitudinal modulus of tissue but cannot provide structural images. Thus, it is limited for imaging dynamic processes such as neural tube formation and closure. To overcome this limitation, we have combined Brillouin microscopy and OCT in one coaligned instrument. OCT provided depth-resolved structural imaging with a micrometer-scale spatial resolution to guide stiffness mapping by Brillouin modality. 2D structural and Brillouin frequency shift maps were acquired of mouse embryos at gestational day (GD) 8.5, 9.5, and 10.5 with the multimodal system. The results demonstrate the capability of the system to obtain structural and stiffness information simultaneously.
Here's my website: https://www.selleckchem.com/products/pi3k-hdac-inhibitor-i.html