侧入式无导光板自然光平板灯

提出了一种侧入式无导光板自然光平板灯的设计方法.利用有机玻璃光纤将收集的自然光传导至平板灯里,为达到均匀的自然光出光效果,通过柱面透镜将光纤的输出光会聚并掠射在带有自由曲面的反光背板上.借助Tracepro软件设计不同投射角下的自由曲面反光背板并仿真,结果表明:设计的灯具照度均匀度达到94.1%.该灯具不仅可以解决LED的蓝光危害问题而且制作流程简单.该设计对太阳光转化为功能性照明和绿色照明具有借鉴意义.     

X-Ray Analysis of Light Elements by Monochromatic Light

As variable energy monochromatic sources both synchrotron radiation monochromatic light and proton induced X-ray emission were used to study X-ray florecence of K、Ca、Ti light elements. The results indicate that this method not only reduces the bremsstrahlung background but also eliminates the interference with some other elements by selecting appropriate exciting energy. Thus the analytic sensitivity of K、Ca、Ti elements are considerably improved.     

直接出射白光的新型发光二极管

介绍了实现出射白光发光二极管的几种方法,包括波长转化产生白光,多有源区级联合成白光以及单个有源区直接出射白光.并从芯片结构、材料选取、白光形成机理以及器件性能等四个方面对这几种方法进行了分析比较.最后指出了实现直接出射白光的发光二极管存在的问题及今后的研究重点.     

Propagation of Light

The speed of light from a uniformly translating source can be deduced, rather than postulated. The deduction, based on the relativity of the Doppler effect, shows that the propagation of light is independent of its source motion (absolute propagation) only if the source is at relative rest. For a relatively translating source, the speed of light in etherless vacuous space is shown to be relative and does depend on the motion-of its source.     

Light Calorimeters

The heat losses in mechanical light calorimeters of various sensitivities for measuring the energy of the light pulse emitted by the fireball of a powerful nuclear explosion were measured experimentally and calculated theoretically.     

LED背光源中侧发光导光管长度与出光性能的关系

微细侧发光导光管可以将LED点光源转化成线光源.为了同时发挥LED光源和CCFL光源的优势,本文对导光管模型进行了改进,使不同长度导光管均能满足良好的出光性能.在网点公式基础上引入非线性修正参数α,并找到导光管长度与α的对应关系,得到不同长度导光管的优化网点排布形式.针对较短导光管光能利用率偏低的问题,采用导光管一端入...     

Readout of Images on Spatial Light Modulator Using Reading Light Supplier

A readout function of a reading light supplier (RLS) is demonstrated by reading out images from an optical addressable spatial light modulator (SLM). The RLS supplies reading light to the reading side of the SLM and transmits readout images from the SLM. The RLS consists of a fiber plate and a redirector which has micro conical-hollows. The RLS contrast, which is the intensity ratio of the reading light to the stray light, is 9.2 and the power efficiency of the reading light supply is about 5%. A writing pattern on the SLM is a checkered pattern of 5 mm×5 mm cells, and it is read out successfully using the RLS. The maximum contrast of the readout image is 1.9.     

激光光源-在线荧光光谱检测中的光强度比较研究

基于激光光源和氙灯光源在线荧光光谱法测定罗丹明B、维生素B₂、荧光素和异硫氰酸荧光素含量比较研究激光光源产生的荧光强度和氙灯光源产生的荧光强度。罗丹明B、维生素B₂、荧光素和异硫氰酸荧光素浓度均为10 μg·mL-1,积分时间100 ms,测定3次得其平均值。在线荧光光谱法最大吸收波长分别为580,450,488和510 nm;最大发射波长依次为594,530,525和524 nm。紫外-可见分光光度法测得其最大吸收波长为557,441,481和490 nm;荧光分光光度法测得其最大发射波长为586,520,519和520 nm。通过测定药物,发现激光光源产生的荧光光强度较强于氙灯光源产生的荧光光强度,原因不仅跟光源有关,而且与药物分子的共轭体系大小、共轭大π键的共平面性及其刚性程度、分子母体上取代基的种类有关,分子所处的外界环境如温度、溶剂、溶液酸碱度、激发光的照射等因素也会影响荧光效率。激光光源和氙灯光源产生的荧光光强度大小顺序为罗丹明B>荧光素>异硫氰酸荧光素>维生素B₂。激光光源在线荧光光谱法在一定程度上填补了在线荧光光谱仪在食品、药品痕量检测方面应用的空白。     

Self-Trapping of Extreme Light

Radiophysics and Quantum Electronics - We use the qualitative, simplified modeling, and approximately self-consistent nonlinear-optical approaches to explain the nature of the regime under which...     

Photodisintegration of Light Nuclei

The first microscopic calculation of inelastic reactions on nuclei with mass number A = 6 is presented. In particular, we consider the total photoabsorption cross section of ⁶He and ⁶Li. It is shown that the halo nucleus ⁶He exhibits two types of dipole resonances, the normal giant dipole resonance and a low-energy soft dipole resonance associated with the excitation of the outer neutrons. Comparing our results with available experimental data we note the role of P-wave interaction. Calculations are performed using the Lorentz integral transform (LIT) method and the effective interaction in the hyperspherical harmonics formalism (EIHH).     

Photodisintegration of Light Nuclei

Recent results of photodisintegration of deuteron and ³He measured with the CEBAF Large Acceptance Spectrometer at Jefferson Lab are reported. The onset of dimensional scaling is investigated in the two-body photodisintegration of ³He, with the results indicating a scaling onset at remarkably low energy and momentum transfer. Results on the azimuthal asymmetry of deuteron photodisintegration are expected to aid in understanding the dominant mechanisms of deuteron photodisintegration and the underlying dynamics in the medium-energy region. In this region, neither effective field theories nor perturbative QCD can be used to describe the reaction, and understanding the underlying dynamics is based on phenomenological quark models.     

Light vector mesons

This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to the light vector mesons; the modification of the spectral shape in search of chiral symmetry restoration and suppression of the meson production in heavy ion collisions. The experimental results show that the spectral shape of light vector mesons are modified compared to the parameters measured in vacuum. The nature and the magnitude of the modification depends on the energy density of the media in which they are produced. The suppression patterns of light vector mesons are different from the measurements of other mesons and baryons. The mechanisms responsible for the suppression of the mesons are not yet understood. Systematic comparison of existing experimental results points to the missing data which may help to resolve the problem.     

Ultrashort Light Pulses

Ultrashort Light Pulses     

光与信息

光不仅是维持生命活动的主要能量来源,也是一种有效的信息载体。阐述了光作为载体与信息之间的密切联系,讨论了海森堡不确定性原理对信息的解释,即每一比特信息都对应着一个光量子,受限于所在的信息元,并且与熵的消耗相关。分别给出了满足不确定性原理条件以及超出该限制时的例子,从而证明了时间和频率的分辨率不能被同时观测,但成像仍然可以在确定性条件的限制下获得。