基于激光三角法对透明平板厚度测量光线补偿的研究及应用

提出了一种基于激光三角法光线折射补偿对透明平板厚度测量的方法,设计了基于单激光位移传感器的透明平板厚度测量装置,并应用于准分子激光投影光刻加工透明材料时的像面校准。首先构建了激光三角法测量情形下偏折光线和透明平板位置之间的关系,分析了散射光斑因折射发生的位置偏移量与平板厚度之间的关系,以及透明平板与散射基面的间距和散射基面位置的变化对测量结果产生的影响。然后设计了基于单激光位移传感器的透明平板厚度测量装置,实验验证了散射光斑偏移量和平板厚度之间的对应关系,测得了聚甲基丙烯酸甲酯(PMMA)厚度测量的补偿系数为0.441。综合理论分析和实验验证,结果表明散射光斑偏移量与透明平板的厚度呈线性变化关系,透明平板与散射基面间距的大小对测量结果无影响,散射基面偏移量与传感器探头示数变化量相等。PMMA平板厚度测量的平均绝对误差小于0.01 mm,平均相对误差为0.6%,能够满足准分子激光(Kr F,248 nm)加工PMMA基生物芯片的精度要求。

危重症儿童睡眠环境光线与噪声暴露水平调查研究

目的了解危重症儿童睡眠环境光线与噪声暴露水平,为制定相应的睡眠促进策略提供依据。方法方便选取某儿童专科医院PICU病房2022年12月至2023年6月入住的121例患儿作为研究对象,对患儿睡眠时暴露的室内光线及声音水平进行测量并分析。结果危重症患儿不同时间段的光照及噪声暴露强度不同,其中白天14~354 lx、晚6点~次日凌晨2点睡眠时在9~366 lx之间、晨2点~8点在5~187 lx之间。白天睡眠噪声强度为(56.63±7.0)dB、晚6点~次日凌晨2点为(53.93±4.62)dB、晨2点~8点睡眠时平均噪声暴露强度为(52.73±4.94)dB。结论危重症儿童睡眠暴露光线强度适中,噪声暴露强度较高,医院管理者应重视对重症监护室睡眠环境管理,着重降低监护室噪声水平。

具有语音播报功能的温度与光线测控仪

以凌阳单片机SPCE061A作为控制板,配合传感器模组对周围环境温度和光线进行测量,并自动调节光线强度,通过人性化的语音提示和播报功能,成功地实现了温度与光线测控仪的设计。给出了系统的硬件组成,并具体阐述了软件设计过程。

分析电力通信光纤测量要点

电力通信是电力生产中的重要环节，光纤是电力通信系统中重要的基础性物理通道，在开展电力通信通道的组建中，光纤测量是非常重要的工作环节。本文就电力通信光纤测量原理、方式、参数设定、测量误差处理等测量要点进行重点介绍。

Single Camera 3-D Coordinate Measuring System Based on Optical Probe Imaging

A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced which can distinguish six freedom degrees of optical probe to realize coordinate measurement of the object surface. The effects of some factors on the resolution of the system are analyzed. The simulating experiments have shown that the system model is available.

Application of 2-D Position Sensitive Detector in Spatial Straightness Measurement of Guide Rails

A laser collimating system based on 2-D position sensitive detector (PSD) is presented in this paper. The working principle of PSD is depicted in detail. A calibration device was developed to check the nonlinearity errors of PSD and a multilayer feedforward neural network based on error back-propagation algorithm was used to compensate errors. With the aid of computer-based data acquisition system, an automatic dynamic measuring process was realized. A series of experiments, including comparison tests with laser interferometer, were done to evaluate the performance of the measuring system. The experimental results show that the spatial straightness errors of guide rails can be measured with high accuracy. The maximum differences between the device and laser interferometer are 0.027 mm in Y direction, and 0.053 mm in X direction in the measuring distance of 6 m.

Teleportation of Bipartite Entangled State Without Joint Measurement

In this paper, we present a probabilistic teleportation scheme for unknown bipartite entangled state. By using linear optical elements, we convert the Bell-state measurement into separated single-qubit measurements.

Novel Optical Fiber Gas Sensor for On-line Measurement of Methane

Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measurement is presented in this paper. In order to eliminate the noise, the ratio of the fundamental and second-harmonic signals is used. The mathematical model of gas concentration harmonic measurement is built up.The detection result of methane concentration is also shown. Experiments have proved a sensitivity of 28×10-6.

Realization of Bipartite Positive-Operator-Value Measurements of Two-Photon Polarization States

In this letter, we propose a scheme of a special quantum optical Fredkin gate assisted by optical manip- ulations and postselection from the coincidence measurements, and then modify it with cross-Kerr nonlinearities to be suitable for the realization of all possible positive operator-valued measurements of bipartite polarization states. This scheme is feasible in the lab with the current experimental technology.

Generation of Four-Photon Cluster State with Coherent Light via Cross-Kerr Nonlinearity

We propose two schemes for preparing four-photon cluster state through cross-Kerr nonlinearity. Two coherent fields interact when they enter a nonlinear Kerr medium. If the interaction time is chosen appropriately in each Kerr medium, four-photon cluster state can be generated based on the results of two homodyne detectors in the first scheme. These schemes only use Kerr medium and homodyne measurements on coherent light fields, which can be effciently made in quantum optical laboratories. In addition, weak cross-Kerr nonlinearity is sufficient. All of the properties make these schemes feasible in experiments.

Modified Multispectral Space for Color Representation

Conventional multispectral space for color representation is modified by algorithm of cluster analysis and principal component analysis. Results show that the newer modified multispectral space not only keeping the structure of the original space but eliminating zero crosses as well its accuracy of color representation is higher than the conventional.

A Novel Method to Simultaneously Measure the Straightness

A precise two-degree-of-freedom measuring system (2DMS) is developed based on single-mode optical fiber, LD, cube corner retroreflector and four-quadrant photodetector (4-Q), and the simultaneous on-line measurement of lateral and vertical direction straightness errors of the linear stage is carried out. The moving part is wireless, which eliminates any errors introduced by pushing and pulling the wires. The sensitivity of the straightness error measurement can be improved by a factor of 2 with the cube corner retroreflector. This fiber-based optically aligned beam is used to establish a reference line for the straightness measurement of any mechanical system. 4-Q detector is used to receive the laser beam. A chip microcomputer is developed to conduct all data acquisition and signal processing. The beam drift influence can be removed in the greatest extent from the system. The experiments on the measurement system stability, repeatability and its comparison with the HP5528 double-frequency laser interferometer are carried out.

Experimental Verification of Doppler Effect with the Refraction Method

The traditional method of measuring Doppler Effect is either reflection or dispersiion. This article clarifies that it can also verify the Doppler Effect with the refraction method. We have designed the experimental system with the method of optical heterodyne, using the refraction light beam from a prism, and made the experiment. The experimental results are in accordance with the theoretical calculation. It is very useful in some particular case, such as in Negative- Index Materials（NIM）, to verify the Doppler Effect with this method.

Loss Measurements on Polymer Thin Film Optical Waveguides

A simple setup for the measurement of transmission loss in polymer thin film optical waveguides is described. A new electro-optic polymer film has been prepared. The transmission loss of the film is measured before and after corona poling. And the loss is determined to be 1.84 dB/cm and 2.14 dB/cm, respectively.

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S^1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.

Natural Radioactivity Measurements for Some Algerian Building Materials

The objective of this work is to assess the radiation hazards associated gamma rays from building materials. Natural gamma rays activities of natural radionuclide represented mainly by three natural radioactive series ^238U, ^235U and ^232Th, and the primordial ^40K in the samples of building materials which consist of bricks, ceramics, marble and gypsum from different areas of eastern Algeria are measured using gamma ray spectrometry. The values of the activities of these radionuclides do not clearly reflect the radiation hazard associated with these materials. Therefore, the radium equivalent （Raeq） concentration is defined taking into account the effectiveness of these isotopes in creating the radiation hazard. Radium equivalent activities, external and internal hazard indices （Hex and Hin） are calculated from the activities of ^226Ra, ^232Th and ^40K for suitability of the materials.

Scanning electron microscopy coupled with energydispersive X-ray spectrometry for quick detection of sulfuroxidizing bacteria in environmental water samples

Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.

Measuring radial Young’s modulus of DNA by tapping mode AFM

Based on tapping mode AFM imaging, a method was demonstrated to evaluate compression elasticity of single double-stranded DNA (dsDNA) molecules in the force region. With images under ambient conditions, Young’s moduli of dsDNA in compression were calculated. Results demonstrated that Young’s moduli of dsDNA can be simply deduced according to the proposed model. The method can also be used to evaluate the compression elasticity of similar soft nanomaterials.

Minimum detectable activity for NaI(Tl) airborne γ-ray spectrometry based on Monte Carlo simulation

The determination of the effective minimum detectable activity （MDA） of radionuclides by a detection system plays an im- portant role in environmental radiation monitoring. In this study, the responses of an NaI（TI） airborne γ ray spectrometry （AGRS） system to different radionuclides （137Cs and 131I） were investigated using the Monte Carlo technique. The MDA values were determined under different conditions according to the counting spectra obtained from the Monte Carlo simulation. The equivalent mass thickness method was applied to the Monte Carlo modeling for monitoring ground radiation to reduce sta- tistical uncertainty. The secondary source method was used to monitor both air and ground radiation. A quadratic relationship was found between the MDA and activity concentration. An exponential relationship was found between the MDA and altitude The MDA of a specific radionuclide from external detectors was found to be superior to that obtained from internal detectors under the same conditions. The MDA values in an NaI（Tl） AGRS system under different conditions can be estimated based on the results of this study.

All-optical scheme for detecting the possible Majorana signature based on QD and nanomechanical resonator systems

Majorana fermions(MFs) are exotic particles that are their own anti-particles. Currently, the search for MFs occurring as quasiparticle excitations in condensed matter systems has attracted widespread interest, because of their importance in fundamental physics and potential applications in topological quantum computation based on solid-state devices. Motivated by recent experimental progress towards the detection and manipulation of MFs in hybrid semiconductor/superconductor heterostructures, in this review, we present a novel proposal to probe MFs in all-optical domain. We introduce a single quantum dot(QD), a hybrid quantum dot-nanomechanical resonators(QD-NR) system, and a carbon nanotube(CNT) resonator implanted in a single electron spin system with optical pump-probe technology to detect MFs, respectively. With this scheme, a possible Majorana signature is investigated via the probe absorption spectrum and nonlinear optical Kerr effect, and the coupling strength between MFs and the QD or the single electron spin is also determined. In the hybrid QD-NR system, vibration of the NR will enhance the nonlinear optical effect, which makes the MFs more sensitive for detection. In the CNT resonator with a single electron, the single electron spin can be considered as a sensitive probe, and the CNT resonator behaved as a phonon cavity is robust for detecting of MFs. This optical scheme will provide another method for the detection MFs and will open the door for new applications ranging from robust manipulation of MFs to quantum information processing based on MFs.