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INTRODUCTION AND IMPORTANCE: Fever is a common clinical symptom in patients with postoperative scoliosis. However, there are rare reports of immediately fevers occurring following operative procedures. CASE PRESENTATION: A 15-year-old female with a 1-year history of scoliosis was admitted to the hospital after a health examination. The patient was diagnosed with idiopathic scoliosis and underwent a posterior idiopathic scoliosis procedure and correction for pedicle fixation. The clinical symptoms, including chills, fever, increased heart rate and increased blood pressure, were observed immediately following surgery during anaesthesia recovery. The patient was discharged from the hospital 12 days post-surgery. Over the 90-day follow-up, no chills, fever (≥38 °C), deep tissue infection, or surgery-related complications were reported. This remained consistent for the subsequent 3-year follow-up. CLINICAL DISCUSSION: The patient was discharged 12 days after the operation, and no chills or fever (≥38 °C) occurred during the 90-day follow-up. Furthermore, there were no instances of deep tissue infection or any other surgery-related complications throughout the subsequent 3-year follow-up duration. A literature review has performed for this subject by systematic review. We identified only three reports that specifically examined postoperative fever as an observational measure among spine surgical patients. Unfortunately, none of these reports mentioned immediate postoperative fever. CONCLUSION: Based on the available clinical data and research evidence, it is recommended to exercise caution when treating patients who experience postoperative chill and fever, as it may be caused by a combination of intraoperative hypothermia and anaesthesia inhibition. While these symptoms may be self-limiting in nature, close monitoring and appropriate management should be implemented to ensure patient safety and to identify any potential complications.

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In laser direct writing lithography, there is not any image information from the sample surface, which makes it difficult to find the position of the focal plane. To overcome the problem, an autofocusing through the crosshair projection method is proposed in this work. The crosshair on the reticle is inserted into the lighting path and imaged onto the sample surface. The addition of the crosshair projection increases the image information from the sample surface, meeting the requirement for the image information in focusing and improving the focusing environment. Furthermore, this work presents what we believe to be a new division of the focusing curve based on the range of the perpendicular feature extracted from the crosshair projection during the focusing process. The perpendicular feature can be extracted from the crosshair projection in the focusing zone but not in the flat zone. Compared with the traditional division, this new division enables the use of the perpendicular feature to directly determine the zone of the current sample position and to find the focusing zone during the focusing process. This can completely filter out the interference of local fluctuations in the flat zone, greatly facilitating the sample focusing. The autofocusing process was designed based on this division, and experiments were carried out accordingly. The focusing accuracy is about 0.15 µm, which is in the range of the depth of focus of the optical system. The results show that the proposed method provides a good solution to achieve accurate focusing based on the crosshair projection image from the sample surface in laser lithography.

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In this work, complex Chinese micropatterns are experimentally inscribed in AgInSbTe thin films through laser writing technique. The overlapping inscription strategy is introduced to reduce the size of complex Chinese micropatterns, and the erosion algorithm is used to eliminate sticking effects among fine strokes in complex Chinese micropatterns. The results show that the size of complex Chinese micropatterns can be reduced to around 15.41µm×15.41µm. The width of the finest stroke is only 0.45 µm. This method can achieve a fidelity of 95%. This work helps with the long-term preservation of massive Chinese character archives.

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For achieving high-resolution nanostructures for next-generation diffractive optical elements (DOEs) using an environmentally friendly process, an electrochemical development strategy is proposed and developed using AgInSbTe-based laser heat-mode resist (AIST-LHR). Based on the electrical resistivity difference of amorphous and crystalline phases for this resist, an etching selectivity ratio of ≈30:1 (i.e., the etch ratio between the amorphous and crystalline ones) is achieved through the oxidation of Fe3+ ions with the assisted pitting activation etching using Cl- ions in an acid medium. Nanostructures with a minimum feature size down to 41 nm are successfully generated, including grating patterns, meta-surface optical structures, gears, and English characters. Using a post-plasma etching process, the nanostructures are successfully transferred from the AIST-HLR onto silica substrate, and X-ray grating patterns with a line space of 80 nm are created as a demonstration for its potential applications in DOEs.

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To date, the second harmonic generation (SHG) has a great effect on photonic devices. However, it is a formidable challenge to achieve reconfigurable SHG. Hereby, we experimentally demonstrate the SHG response from the oriented Ge2Sb2Te5 (GST) grains induced by polarized laser pulses for the first time. The orientation of GST grains is found to be perpendicular to the polarization direction of the pump laser. Such unique ordered structures result in a periodic change of SHG intensity with the input polarization angle of the pump laser rotating every 180°. These findings may pave avenues for generating nonlinear optical sources with a simple process, scalability, and switchable functionality.

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The movement flatness error is one of the critical parameters of motorized stage performance. In this work, the measurement of the movement flatness error based on an astigmatic method is proposed, in which the focus error signal is detected and used to analyze the movement flatness error. The theoretical derivation and analysis are presented, and the experimental system is established accordingly. The experimental results indicate that our measurement method and established system exhibit an accuracy of less than ±100 nm. The movement flatness error of an x-y stepping motorized stage is measured using the established system, and the movement flatness error profile is mapped; it is determined that the maximum movement flatness error is within 1.3 µm in our experiment. The proposed method is hence proven to be an effective way of measuring the movement flatness error of motorized stages.

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Sb2Te3 thin films are widely used in high density optical and electronic storage, high-resolution greyscale image recording, and laser thermal lithography. Thermal conductivity and its temperature dependence are critical factors that affect the application performance of thin films. This work aims to evaluate the temperature dependence of thermal conductivity of crystalline and amorphous Sb2Te3 thin films experimentally and theoretically, and explores into the corresponding mechanism of heat transport. For crystalline Sb2Te3 thin films, the thermal conductivity was found to be 0.35 ± 0.035 W m-1 K-1 and showed weak temperature dependence. The thermal conductivity of amorphous Sb2Te3 thin films at temperatures below ~450 K is about 0.23 ± 0.023 W m-1K-1, mainly arising from the lattice as the electronic contribution is negligible; at temperatures above 450 K, the thermal conductivity experiences an abrupt increase owing to the structural change from amorphous to crystalline state. The work can provide an important guide and reference to the real applications of Sb2Te3 thin films.

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Semiconductor diode-based laser patterning with visible light has been extensively applied to the fabrication of arbitrary structures. However, recently, the technique has faced a great challenge because it cannot meet nanoscale-resolved patterning fabrication due to the optical diffraction limit, which is an inherent drawback in the field of optics. To attack the question, copper(ii)-hydrazone-complex (CuL2) thin films are used as laser patterning materials. Under the heating of a writing laser spot, one-step laser nanopatterning on the CuL2 thin films is obtained. The convex-type and concave-type pattern structures are directly written without wet-etching and developing processes. The minimum pattern feature size is about 31 nm, which is far smaller than the diffraction limit and only ∼1/20 the writing spot size. Analysis indicates that the laser nanopatterning originates from obvious photothermal localization responses to the writing spot. Compared with common organic resists, the exposure dose of CuL2 is several orders higher than that of the polymer; thus CuL2 thin film materials are suitable for maskless direct laser writing lithography. This work also provides an effective method for one-step nanopatternings through diode-based laser writing at visible light wavelengths.

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High-speed maskless nanolithography is experimentally achieved on AgInSbTe thin films. The lithography was carried out in air at room temperature, with a GaN diode laser (λ = 405 nm), and on a large sample disk of diameter 120 mm. The normal width of the written features measures 46 ± 5 nm, about 1/12 of the diffraction allowed smallest light spot, and the lithography speed reaches 6 ~ 8 m/s, tens of times faster than traditional laser writing methods. The writing resolution is instantaneously tunable by adjusting the laser power. The reason behind the significant breakthrough in terms of writing resolution and speed is found as the concentration of light induced heat. Therefore, the heat spot is far smaller than the light spot, so does the size of the written features. Such a sharp focus of heat occurs only on the selected writing material, and the phenomenon is referred as the photothermal localization response. The physics behind the effect is explained and supported with numerical simulations.

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Chalcogenide Ge2Sb2Te5 thin films have been widely exploited as binary bit recording materials in optical and non-volatile electronic information storage, where the crystalline and amorphous states are marked as the information bits "0" and "1", respectively. In this work, we demonstrate the use of Ge2Sb2Te5 thin films as multi-level grayscale image recording materials. High-resolution grayscale images are recorded on Ge2Sb2Te5 thin films through taking advantage of laser-induced structural evolution characteristic. Experimental results indicate that the change of laser energy results in the structural evolution of Ge2Sb2Te5 thin films. The structural evolution induces the difference of electronic polarizability and reflectivity, and high-resolution grayscale images are recorded on Ge2Sb2Te5 thin films through direct laser writing method, accordingly.

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The resolution of light imaging is required to extend beyond the Abbe limit to the subdiffraction, or even nanoscale. In this Letter, we propose to extend the resolution of scanning optical microscopy (SOM) beyond the Abbe limit as a kind of subdiffraction imaging technology through the assistance of InSb thin layers due to obvious nonlinear saturation absorption and reversible formation of an optical pinhole channel. The results show that the imaging resolution is greatly improved compared with the SOM itself. This work provides a way to improve the resolution of SOM without changing the SOM itself, but through the assistance of InSb thin layers. This is also a simple and practical way to extend the resolution of SOM beyond the Abbe limit.

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The resolution of far-field optical imaging is required to improve beyond the Abbe limit to the subdiffraction or even the nanoscale. In this work, inspired by scanning electronic microscopy (SEM) imaging, in which carbon (or Au) thin films are usually required to be coated on the sample surface before imaging to remove the charging effect while imaging by electrons. We propose a saturation-absorption-induced far-field super-resolution optical imaging method (SAI-SRIM). In the SAI-SRIM, the carbon (or Au) layers in SEM imaging are replaced by nonlinear-saturation-absorption (NSA) thin films, which are directly coated onto the sample surfaces using advanced thin film deposition techniques. The surface fluctuant morphologies are replicated to the NSA thin films, accordingly. The coated sample surfaces are then imaged using conventional laser scanning microscopy. Consequently, the imaging resolution is greatly improved, and subdiffraction-resolved optical images are obtained theoretically and experimentally. The SAI-SRIM provides an effective and easy way to achieve far-field super-resolution optical imaging for sample surfaces with geometric fluctuant morphology characteristics.

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In order to realize high-speed laser writing arbitrary patterns, we establish a set of high-speed polar coordinate laser writing system. Although the polar coordinate laser writing system is generally suitable for fabricating circular symmetric patterns, there are challenges when dealing with arbitrary patterns. Here, we propose an effective method to solve this problem by converting the pattern data from Cartesian coordinates to polar coordinates for high-speed laser writing of arbitrary patterns. Several types of arbitrary patterns are written on chalcogenide thin films with a minimum pattern linewidth of 700 ± 70 nm and a maximum writing speed of approximately 10 m/s, which corresponds to more than 600 mm2/min at 1.0 µm linewidth. This writing speed is ten times faster than that of the conventional x-y type Cartesian coordinate laser writing system.

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This work focuses on the strong nonlinear saturation absorption (NSA)-induced optical super-resolution effect. A multi-layer system model is proposed to understand the strong NSA-induced formation of an optical pinhole channel and the generation of a super-resolution spot. Taking a Sb2Te3 thin film as an example, numerical simulations were conducted. The results illustrate that an optical pinhole channel is clearly formed by the NSA characteristics. This pinhole channel is similar to a near-field light probe. Light travels through the pinhole channel, and a super-resolution spot is generated at its apex. The near-field spot scanning experimental results show that the reduction ratio of the spot is approximately 44.8%, which is basically consistent with the numerical simulation result of 43%. This work is helpful for understanding optical nonlinear super-resolution effects and developing nanolithography, nanodata storage, high-resolution optical imaging technologies with nonlinear thin films.

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This study explores how interference manipulation breaks through the diffraction limit and induces super-resolution nano-optical hot spots through the nonlinear Fabry-Perot cavity structure. The theoretical analytical model is established, and the numerical simulation results show that when the thickness of the nonlinear thin film inside the nonlinear Fabry-Perot cavity structure is adjusted to centain value, the constructive interference effect can be formed in the central point of the spot, which causes the nanoscale optical hot spot in the central region to be produced. The simulation results also tell us that the hot spot size is sensitive to nonlinear thin film thickness, and the accuracy is required to be up to nanometer or even subnanometer scale, which is very large challenging for thin film deposition technique, however, slightly changing the incident laser power can compensate for drawbacks of low thickness accuracy of nonlinear thin films. Taking As(2)S(3) as the nonlinear thin film, the central hot spot with a size of 40nm is obtained at suitable nonlinear thin film thickness and incident laser power. The central hot spot size is only about λ/16, which is very useful in super-high density optical recording, nanolithography, and high-resolving optical surface imaging.

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Chalcogenide phase-change thin films are used in many fields, such as optical information storage and solid-state memory. In this work, we present another application of chalcogenide phase-change thin films, i.e., as grayscale photolithgraphy materials. The grayscale patterns can be directly inscribed on the chalcogenide phase-change thin films by a single process through direct laser writing method. In grayscale photolithography, the laser pulse can induce the formation of bump structure, and the bump height and size can be precisely controlled by changing laser energy. Bumps with different height and size present different optical reflection and transmission spectra, leading to the different gray levels. For example, the continuous-tone grayscale images of lifelike bird and cat are successfully inscribed onto Sb(2)Te(3) chalcogenide phase-change thin films using a home-built laser direct writer, where the expression and appearance of the lifelike bird and cat are fully presented. This work provides a way to fabricate complicated grayscale patterns using laser-induced bump structures onto chalcogenide phase-change thin films, different from current techniques such as photolithography, electron beam lithography, and focused ion beam lithography. The ability to form grayscale patterns of chalcogenide phase-change thin films reveals many potential applications in high-resolution optical images for micro/nano image storage, microartworks, and grayscale photomasks.

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Laser thermal lithography is a good alternative method for forming small pattern feature size by taking advantage of the structural-change threshold effect of thermal lithography materials. In this work, the heat-diffusion channels of laser thermal lithography are first analyzed, and then we propose to manipulate the heat-diffusion channels by inserting thermal conduction layers in between channels. Heat-flow direction can be changed from the in-plane to the out-of-plane of the thermal lithography layer, which causes the size of the structural-change threshold region to become much smaller than the focused laser spot itself; thus, nanoscale marks can be obtained. Samples designated as "glass substrate/thermal conduction layer/thermal lithography layer (100 nm)/thermal conduction layer" are designed and prepared. Chalcogenide phase-change materials are used as thermal lithography layer, and Si is used as thermal conduction layer to manipulate heat-diffusion channels. Laser thermal lithography experiments are conducted on a home-made high-speed rotation direct laser writing setup with 488 nm laser wavelength and 0.90 numerical aperture of converging lens. The writing marks with 50-60 nm size are successfully obtained. The mark size is only about 1/13 of the focused laser spot, which is far smaller than that of the light diffraction limit spot of the direct laser writing setup. This work is useful for nanoscale fabrication and lithography by exploiting the far-field focusing light system.

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In this work, we theoretically and experimentally study the physical process of Airy beams induced by binary phase patterns combined with a slope factor. Theoretical simulations show that the binary phase patterns generate a pair of symmetrically inverted twin Airy beams. The slope factor can regulate the spacing between the two Airy beam peaks, decrease the error induced by the binarization process, and adjust the position of the focus formed by the twin Airy beams. The experimental results are consistent with the theoretical ones.

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Nano-optical information storage is very important in meeting information technology requirements. However, obtaining nanometric optical information recording marks by the traditional optical method is difficult due to diffraction limit restrictions. In the current work, the nonlinear saturable absorption effect is used to generate a subwavelength optical spot and to induce nano-optical information recording and readout. Experimental results indicate that information marks below 100 nm are successfully recorded and read out by a high-density digital versatile disk dynamic testing system with a laser wavelength of 405 nm and a numerical aperture of 0.65. The minimum marks of 60 nm are realized, which is only about 1/12 of the diffraction-limited theoretical focusing spot. This physical scheme is very useful in promoting the development of optical information storage in the nanoscale field.

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Industrial approaches to improve lithographic resolution usually rely upon short-wavelength laser or charged particles of even shorter wavelengths. However, nanoscale lithography with visible light is more effective for practical applications because of its low cost, easy operation, and so on. In the current work, a technical scheme for the optical nonlinear saturable absorption effect to induce nanobump pattern structures is proposed. The theoretical simulation indicates that the spot size can be squeezed and reduced to about 1/12 the original spot size using Si thin films as a nonlinear saturable absorption material, and GaN semiconductor diode as the laser source. The high-density digital versatile disk tester was used as the direct laser writing apparatus to verify the technical scheme. Nanostructures with a size of ∼80 nm were obtained. This size is ∼1/10 the spot size at optical diffraction limit.

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