Ionization is a fundamental process in intense laser-matter interactions and is known to cause plasma defocusing and intensity clamping. Here, we investigate theoretically the propagation dynamics of an intense laser pulse in a helium gas jet in the ionization saturation regime, and we find that the pulse undergoes self-focusing and self-compression through ionization-induced reshaping, resulting in a manyfold increase in laser intensity. This unconventional behavior is associated with the spatiotemporal frequency variation mediated by ionization and spatiotempral coupling. Our results illustrate a new regime of pulse propagation and open up an optics-less approach for raising laser intensity.A laser is meant to emit coherent radiation at a particular wavelength. Here, we demonstrate a laser that is prohibited to emit at a particular wavelength, called a dark line in the emission background of its gain spectrum. Specifically, we installed a 150 µm thick etalon mirror on an ytterbium-doped fiber laser. The laser suffers from 100% loss at the resonance of the etalon and generates a dark line in its emission spectrum. The interplay among the etalon resonance, homogenous gain broadening, and gain competition allows wavelength tuning and multiple-color emission from the laser.Fabrication of large optics is a time-consuming process and requires a vast investment in manpower and financial resources. Increasing the material removal rate of polishing tools and minimizing dwell time are two common ways of reducing the processing time. Indeed, the polishing efficiency can be further improved if multiple tools are used at the same time. In this Letter, we propose a dual-tool deterministic polishing model, which multiplexes the dwell time and optimizes the run parameters of two polishing tools simultaneously. The run velocities of the two tools are coordinated by boundary conditions with a velocity adjustment algorithm, and the corresponding polishing paths are studied. We demonstrate this model with a simulation of polishing one segment of the Giant Magellan Telescope, where, with the proposed dual-tool multiplexing, the processing time of an ø8.4 m mirror has been reduced by 50.54% compared with that using two tools in a sequential schedule.We demonstrate a novel, to the best of our knowledge, magneto-optical effect that reveals itself in light intensity modulation without polarization rotation in the Faraday configuration. We design a photonic crystal with a magnetized optical cavity that supports bound states in the continuum (BICs), since it simultaneously provides the extended state (continuum) for TM polarization, and the bound (localized) state in the form of a cavity mode for TE-polarized light. Magnetization of the photonic crystal in the Faraday configuration results in efficient polarization conversion and trapping of the acquired TE components of the TM incident light inside the magnetized optical cavity. As a result, a BIC manifests itself as a significant magneto-optical modulation of transmitted light intensity, while its polarization is preserved. Therefore, the proposed structure is promising for magnetic control of light in various applications.In this Letter, we demonstrate an average output power of 5.12 W at 3-5 µm from a type-I phase-matching BaGa4Se7 (BGSe) optical parametric oscillator (OPO), which is pumped by a 2090 nm Q-switched HoYAG laser with pulse repetition frequency of 1 kHz. At maximum output level, the corresponding slope efficiency and optical-to-optical conversion efficiency are 30.0% and 18.3%, respectively. Moreover, under ring cavity conditions, the BGSe OPO produced a 3.04 W mid-infrared laser with high beam quality factors M2 of 1.47 in the horizontal direction and 1.51 in the vertical direction. Besides, the wavelength-tuning curve for type-I BGSe was also investigated, corresponding to an idler wavelength-tuning range of 4.5-5.3 µm, and the signal light wavelength was 4.5 to 4.1 µm.In this Letter, we propose a tunable coherent perfect absorber based on ultrathin nonlinear metasurfaces. A nonlinear metasurface is made of plasmonic nanoantennas coupled to an epsilon-near-zero material with a large optical nonlinearity. The coherent perfect absorption is achieved by controlling the relative phases of the input beams. Here, we show that the optical response of the nonlinear metasurface can be tuned from a complete to a partial absorption by changing the intensity of the pump beam. The proposed nonlinear metasurface can be used to design optically tunable thermal emitters, modulators, and sensors.Quantitative control of spatial indistinguishability of identical subsystems as a direct quantum resource at distant sites has not yet been experimentally proven. We design a setup capable of tuning remote spatial indistinguishability of two independent photons by individually adjusting their spatial distribution in two distant regions, leading to polarization entanglement from uncorrelated photons. This is achieved by spatially localized operations and classical communication on photons that meet only at the detectors. The amount of entanglement depends uniquely on the degree of spatial indistinguishability, quantified by an entropic measure I, which enables teleportation with fidelities above the classical threshold. The results open the way to viable indistinguishability-enhanced quantum information processing.The performance of planar geometry Ge-on-Si single-photon avalanche diode detectors of 26µm diameter is presented. Record low dark count rates are observed, remaining less than 100 K counts per second at 6.6% excess bias and 125 K. Single-photon detection efficiencies are found to be up to 29.4%, and are shown to be temperature insensitive.  https://www.selleckchem.com/products/suzetrigine.html  These performance characteristics lead to a significantly reduced noise equivalent power (NEP) of 7.7×10-17WHz-12 compared to prior planar devices, and represent a two orders of magnitude reduction in NEP compared to previous Ge-on-Si mesa devices of a comparable diameter. Low jitter values of 134±10ps are demonstrated.We propose a silicon microring resonator (MRR)-based high-resolution interrogator enabled by novel slope-assisted filtering and pulse compression technology for time division multiplexed fiber Bragg grating (TDM-FBG) sensors. Golay coded optical pulses are launched into an FBG sensor array to produce a series of reflected pulses with different time delays due to various transmission distances. A tunable MRR filter is used for interrogation of all FBG sensors by direct detection and subsequent signal processing. As a proof of concept, a strain sensing experiment is conducted using a 2×1 TDM-FBG sensor array. The performance of the proposed interrogation system is evaluated experimentally, and the dynamic strain resolution can be as high as 20nε/Hz.