Spectral properties of Ho:GdVO4 single crystal

Absorption and emission spectral properties of GdVO₄ single crystal doped with Ho³⁺ ions were investigated at room temperature. Polarized absorption cross section is calculated in the range of 400–2200 nm. Results were analyzed and parameters were calculated based on Judd-Ofelt theory, the emission spectrum shows that the emission intensity around the wavelength of 546 nm associated with transition ⁵S₂ → ⁵I₈ is much stronger than other bands in the observed range and potentially enable the green light output around this emission band in this crystal.     

Study on the orientation degree of Pb1 − xLaxTiO3 thin films by the rocking curve technique and its morphological aspects

Thin films of perovskite-type materials such as PbTiO₃, BaTiO₃, (Pb,La)TiO₃, (Pb, La)(Zr,Ti)O₃, KNbO₃, and Pb(Mg,Nb)O₃ have been attracting great interest for applications like non-volatile memories, ultrasonic sensors and optical devices. Thin film should be epitaxially grown or at least highly textured since the properties of this anisotropic material depend on the crystallographic orientation. For optical devices, in particular, an epitaxial thin film without defects are essential to reduce optical propagation losses. Pb_1 − xLa_xTiO₃ (PLT) where x = 0, 13 and 27% thin films were prepared by a chemical method (polymeric precursors method), and deposited by the spin coating technique onto substrates of SrTiO₃ (STO) and LaAlO₃ (LAO). The films were then heat treated at 500 °C in a controlled atmosphere of O₂. The orientation degree of the thin films was obtained from rocking curve technique, by means of X-ray diffraction analysis. A microstructural study revealed that the films were crack-free, homogeneous and have low roughness.     

Optical properties of antimony-implanted ZnO epilayers

Antimony ions were implanted into ZnO films grown on c-plane sapphire by pulsed-laser deposition. Raman scattering modes of the Sb-implanted samples were found to be influenced by the implantation dose. A characteristic peak at 576 cm^− 1 was observed with an asymmetric shape due to ion damage to the lattice of the implanted ZnO films. When the implant dose was low, the height of the peak was reduced by rapid thermal annealing at 400-600 °C and the symmetry of the spectra was recovered. However, when the Sb dose exceeded 1 × 10¹⁵ cm^− 2, the peak maintained unchanged after rapid thermal annealing at temperatures up to 600 °C. A broad and low Raman peak was observed at 437 cm^− 1, which is related to the surface damage caused by the energetic ion bombarding. Photoluminescence measurement showed a decrease of the bandedge emission at 3.36 eV, a clear effect of defects induced by the implantation, and confirmed partial recovery of the crystal by rapid annealing.     

激光超声光学测试仪

提出了一种基于光纤耦合的反射式光偏转原理的激光超声光学检测技术，并成功研制了激光超声光纤传感器。详细讨论了其测试机理。采用该传感器测试了激光超声表面波、兰姆波和纵波，获得了很好的波形。实验结果表明，这种检测技术在测量材料表面微形变方面有较大的发展潜力。     

嵌入式光纤位移传感器信号处理电路的设计

文中介绍了嵌入式光强调制型光纤位移传感器的工作原理，并针对以往信号处理电路的缺点加以改进，设计出一种新的信号处理电路，重点描述了硬件实现方法及其软件开发。其硬件主要由信号调理电路、有效值转换器AD536A和高性能单片机ADuC812组成；软件部分的主要功能是完成两路信号相除、线性化处理和补偿等工作。传感器具有结构简单、线性度好、灵敏度高等优点。     

软件控制吸收型光纤气敏传感器

研究了一种易于实现的软件控制光谱吸收型光纤气体传感器.采用LED作为光源,利用可调谐法布里-珀罗腔的选频特性进行检波,并采用谐波检测,大大提高了检测的灵敏度.同时采用多光路设计和软件控制相结合,在线检测多种气体,克服了以往气体传感器只能检测一种气体的缺点,大大增加了传感器的适用性.     

高密度光盘径向动态特性测量方法研究

分析了现有光盘径向动态特性测量方法的特点，深入研究了一种适用于高密度光盘径向动态特性的基于过道波形信号连续测量方法及其具体实现。比较了该方法与国际标准推荐的测量方法的测量精度，结果表明该方法精度更高，更能适应未来高密度光盘的测试要求。     

Overview and new developments in optical daylighting systems for building a healthy indoor environment

Optical daylighting technology can deliver natural light to a space in a building where daylight is limited. This study gives an overview of two optical daylighting systems for capturing natural light: light pipe systems and mirror sunlighting systems. The literature on optical system theories and developments is identified and commercial products for optical daylighting systems on the market are described. By using a survey of major applications for optical daylighting systems, this study provides practical advice to building designers and researchers and also shows a light pipe system and a mirror sunlighting system developed from this investigation as well as an evaluation of their performance. The evaluation measured the illuminance of the two optical systems installed in a test room and a living room. This study concluded that optical daylighting systems can provide adequate visual comfort and can save energy if they are carefully designed.     

Evaluation of the uncertainty of an optical machine with a vision system for contact-less three-dimensional measurement

Optical machines with a vision system containing a video camera are designed to perform contact-less three-dimensional measurements. They are becoming more widely used in the industrial sector because of the many possibilities for automation they permit and because of the speed and economies in measurement tasks that can consequently be obtained. Within dimensional control these machines introduce significant characteristics of flexibility, savings and reliability. Therefore the purpose is to identify the principal metrological characteristics of such machines and so characterise the metrological traceability of the measurements obtained from them. The aim is to qualify each part of the optical machine as well as on the whole. Previously, no metrological traceability of this equipment has been provided in primary metrology, either at national (SIT—Sistema di Taratura in Italia—Calibration System in Italy) or at international level (EA–European co-operation for Accreditation). For this reason we develop a mathematical model that permits the evaluation of the measurement uncertainties in the use of such a device. The purpose is to obtain the certification of the measurement results furnished by the optical machine in as broad a context as possible. The experimental results of the tests are introduced for validating the proposed method. This paper provides the basis of the expression of the uncertainty of a measurement result obtained using the optical measurement machines and it shows the necessary requirements for the numerical evaluation of such uncertainty.     

光纤位移传感器的线性化处理方法研究

将随机型光纤位移传感器和半圆型光纤位移传感器的输出信号进行处理,得到了较好的线性特性,并且扩大了传感器的测量范围。