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The peak-power-density stability and beam-wander precision of a probe laser are important factors affecting the inspection
results in precise thin-film optical measurements. These factors are also key to evaluating a probe laser for in-line long-time
operation of precise thin-film optical measurements. The peak-power density and beam wander of liner helium–neon (He–Ne) lasers,
random He–Ne lasers, and diode lasers as functions of time are investigated experimentally using a beam profiler. It is found
that the linear polarized He–Ne laser is considered to be a promising candidate for a probe laser employed in precise thin-film
optical measurements due to better peak-power-density stability and beam-wander precision. Both the peak-power-density stability
and beam-wander precision of He–Ne lasers are usually better than that of diode lasers, but an adequate warm-up of He–Ne laser
for 30 min is required before thin-film optical measurements are made. After 12 h operation, the linear polarized He–Ne laser
is suitable for precise thin-film optical measurements because both the peak-power-density stability and the beam-wander precision
reach the minimum level. A cost-effective system composed of two linear polarized He–Ne lasers for long-term operation is
proposed. This system can operate for around 0.5–1.2 years in precise thin-film optical measurements under the normal operating
life of a He–Ne laser by switching the probe laser every 18 h. 相似文献
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本文提出了-种光学非线性薄膜线性参数的方便有效的测量方法,测量了ZnSe非晶态光学薄膜的线性折射率和消光系数。在此方法中,实验数据的计算与处理由-套计算机软件来完成。最后,文章对测量精度进行了简单的讨论。 相似文献
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Optical nonlinearity in semiconducting and insulating thin-film structures is studied by waveguide methods under self-action conditions at a light intensity less than 0.1 W/cm2 and a wavelength of 630 nm. The optical properties vs. light intensity are similar for semiconducting and insulating films, multilayer thin-film structures, and semiconductor-doped glass films. It is demonstrated that the optical nonlinearity and the nonlinear optical constants depend on the interface condition. 相似文献
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讨论了介质薄膜滤波器的色散特点,并推导了单级全通滤波器的理论色散。比较理论色散曲线与实际测量色散曲线,两者吻合较好。但由于单级全通滤波器的色散带宽及斜率不能满足实际所需的色散补偿曲线,因此提出了多级全通滤波器,通过控制级连的单级全通滤波器的谐振波长及反射率,可以增大色散带宽,改善色散斜率,使之满足实用的要求。文中给出了四级全通滤波器的理论色散曲线。 相似文献
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Evaluation of current and temperature effects on optical performance of InGaAlP thin-film SMD LED mounted on different substrate packages
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The relationship between the photometric, electric, and thermal parameters of light-emitting diodes(LEDs) is important for optimizing the LED illumination design. Indium gallium aluminium phosphide(InGaAlP)-based thin-film surface-mounted device(SMD) LEDs have attracted wide attention in research and development due to their portability and miniaturization. We report the optical characterization of InGaAlP thin-film SMD LED mounted on FR4, 2 W, and 5 W aluminum(Al) packages. The optical and thermal parameters of LED are determined at different injection currents and ambient temperatures by combining the T3ster(thermal transient tester) and TeraL ED(thermal and radiometric characterization of power LEDs) systems. Analysis shows that LED on a 5 W Al substrate package obtains the highest luminous and optical efficiency. 相似文献
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C. Molpeceres S. Lauzurica M. Morales J.L. Ocaña J. Cárabe J. Escarré J. Andreu 《Applied Surface Science》2007,254(4):1115-1120
Laser-controlled ablation of individual layers in glass/TCO/thin-film silicon/metal structures is essential for cell isolation and monolithic interconnection in thin-film silicon photovoltaic technologies. More recently, the potential application of laser scribing techniques for the development of photovoltaic matrix position sensors based on a-Si:H has generated much activity, requiring an excellent control in laser-generated patterns obtained by direct material ablation.This work is aimed to determine process parametric windows for a-Si:H thin-film ablation processes using UV ns laser sources in thin-film a-Si:H-based devices. The study is focussed on direct writing techniques using UV sources. We present ablation threshold measurements and process quality assessment using advanced optical microscopy techniques. Moreover only fully commercial laser sources in the ns regime has been used, bearing in mind that thin film based photovoltaic technologies are still demanding further reduction in production costs and, nowadays, ultrafast sources are beyond their scope both for the investment and running cost of those equipments. 相似文献
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The features of the application of an axicon optical system for the LIBS sampling are described. For the axicon sampling, the crater depth is less than that for a conventional spherical lens. The zone of thermal effect around a sampling point is also reduced. The results obtained indicate that the axicon optical system is promising for the thin-film study. 相似文献
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We discuss a new application of a thin-film prism as a beam separator for multimode guided waves in integrated optics. For each mode of propagation, the angle of deflection by the thin-film prism is different and each deflected beam can be processed subsequently. Deflection angles for different modes can be predicted by using the concept of effective index of refraction. The thickness and index of refraction of the guiding film are determined simultaneously by measuring the coupling angles of the laser beam and a simple graphical method. Calculated and observed angles of deflection are in good agreement. The thin-film prism is made by using preferential etching technique in order to obtain linear, well defined, tapered edges. Furthermore, silicon is used as the base material for possible future integration of optical and electronic components. 相似文献
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Grigor’ev L. V. Egorova Ya. B. Bykov N. A. Semenov A. A. Nikitin A. A. 《Optics and Spectroscopy》2019,127(6):1080-1084
Optics and Spectroscopy - The structural, optical, and photoluminescent properties of the thin-film structure ZnO–PLZT ferroelectric ceramics are studied. The results of X-ray diffraction... 相似文献
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Guided-mode resonance Brewster filter 总被引:1,自引:0,他引:1
A new type of optical filter is predicted theoretically and verified experimentally. The filter operates under guided-mode resonance conditions in a thin-film waveguide grating. A high-efficiency reflection filter response is produced at the Brewster angle at which TM reflection is classically prohibited. Low-reflectance sidebands are obtained that are adjacent to the resonance peak induced by the Brewster effect in the neighborhood of the resonance peak. A double-layer waveguide grating yields 94% experimental reflectance at the thin-film Brewster angle for a Gaussian laser beam with TM polarization at the 1064-nm wavelength. 相似文献
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Samuel S. Mao 《Applied Physics A: Materials Science & Processing》2011,105(2):283-288
This article provides an overview of an advanced combinatorial material discovery platform developed recently for screening
semiconductor materials with properties that may have applications ranging from radiation detectors to solar cells. Semiconductor
thin-film libraries, each consisting of 256 materials of different composition arranged into a 16×16 matrix, were fabricated
using laser-assisted evaporation process along with a combinatorial mechanism to achieve variations. The composition and microstructure
of individual materials on each thin-film library were characterized with an integrated scanning micro-beam x-ray fluorescence
and diffraction system, while the band gaps were determined by scanning optical reflection and transmission of the libraries.
An ultrafast ultraviolet photon-induced charge probe was devised to measure the mobility and lifetime of individual thin-film
materials on semiconductor libraries. Selected results on the discovery of semiconductors with desired band gaps and transport
properties are illustrated. 相似文献
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A free-space 1 ×2 wavelength-selective switch (WSS) based on thin-film filter technology is proposed. The 1 × 2 WSS is fabricated with an electromagnetic actuator, a reflecton prism, a narrow-band thin-film filter, and three fiber collimators. The working principle and the configuration of WSS are illuminated. The experimental results indicate a fiber-to-fiber insertion loss ranging from 1.109 to 1.249 dB with 2-V voltage input, which satisfies the application of optical fiber communication. 相似文献
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Xuecheng Liu Bing Xiong Changzheng Sun Jian Wang Zhibiao Hao Lai Wang Yanjun Han Hongtao Li Jiadong Yu Yi Luo 《中国光学快报(英文版)》2021,(6):81-86
A novel thin-film lithium niobate(TFLN) electro-optic modulator is proposed and demonstrated. Li Nb O_3-silica hybrid waveguide is adopted to maintain low optical loss for an electrode spacing as narrow as 3 μm, resulting in a low halfwave-voltage length product of only 1.7 V·cm. Capacitively loaded traveling-wave electrodes are employed to reduce the microwave loss, while a quartz substrate is used in place of a silicon substrate to achieve velocity matching. The fabricated TFLN modulator with a 5-mm-long modulation region exhibits a half-wave voltage of 3.4 V and a merely less than 2 d B roll-off in an electro-optic response up to 67 GHz. 相似文献
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Po-Hsun Lei Shun-Hsi Wang Fuh Shyang Juang Yung-Hsin Tseng Meng-Jung Chung 《Optics Communications》2010,283(9):1933-1937
In this article, we report on the effect of SiO2/Si3N4 dielectric distributed Bragg reflectors (DDBRs) for Alq3/NPB thin-film resonant cavity organic light emitting diode (RCOLED) in increasing the light output intensity and reducing the linewidth of spontaneous emission spectrum. The optimum DDBR number is found as 3 pairs. The device performance will be bad by further increasing or decreasing the number of DDBR. As compared to the conventional Alq3/NPB thin-film organic light emitting diode (OLED), the Alq3/NPB thin-film RCOLED with 3-pair DDBRs has the superior electrical and optical characteristics including a forward voltage of 6 V, a current efficiency of 3.4 cd/A, a luminance of 2715 cd/m2 under the injection current density of 1000 A/m2, and a full width at half maximum (FWHM) of 12 nm for emission spectrum over the 5-9 V bias range. These results represent that the Alq3/NPB thin-film OLED with DDBRs shows a potential as the light source for plastic optical fiber (POF) communication system. 相似文献
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Collinear interaction of optical modes in a thin-film semiconductor waveguide with a space-charge wave increasing along its propagation direction has been investigated. Analytical solutions to the equations of coupled unidirectional and counterpropagating waveguide modes at their phase matching are obtained for the first time, and the dependence of the mode conversion efficiency on the space-charge wave amplification level, the coupling coefficient, and the length of the interaction region of optical modes is analyzed. 相似文献
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The absorption of optical coatings can be measured by the method described with an accuracy of 0.001%. The radiation absorbed
by the optical coating causes a change in the temperature of the coating and the substrate. The temperature change is measured
by means of a thin-film resistance thermometer deposited on the substrate. The method was tested for laser reflectors at 1060
nm with a laser as a light source. 相似文献
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《中国物理 B》2019,(1)
High-performance photodetectors are expected to open up revolutionary opportunities in many application fields, such as environment monitoring, military, optical communication and biomedical science. Combining two-dimensional materials(which have tunable optical absorption and high carrier mobility) with organic materials(which are abundant with low cost, high flexibility and large-area scalability) to form thin-film heterojunctions, high-responsivity photodetectors could be predicted with fast response speed in a wide spectra region.In this review, we give a comprehensive summary of photodetectors based on two-dimensional materials and organic thin-film heterojunctions, which includes hybrid assisted enhanced devices, single-layer enhanced devices, vertical heterojunction devices and tunable vertical heterojunction devices. We also give a systematic classification and perspectives on the future development of these types of photodetectors. 相似文献