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Jinying Li, Ke Chen, Qi Peng, Zhongke Wang, Yang Jiang, Chengyu Fu, Ge Ren
Risley prisms appear to be a promising solution to high-accuracy pointing and tracking. To improve the pointing accuracy of achromatic Risley prisms, an appropriate mathematical model is established, and the forward and inverse solutions are proposed. Focusing on the sources of systematic errors, an optimization method based on a genetic algorithm is proposed to identify the parameters of the physical model, including wedge angles, refractive indexes, and installations. Finally, the experimental platform is established...
September 10, 2017: Applied Optics
Rui Zhang
In a conventional edge-lit backlighting system, a light guide with diffusing dots, prism films and diffusers are used to produce desired light distribution. In such a system, the use of prism films helps to collimate the light, but it also increases the cost and reduces the overall optical efficiency. This paper proposes a novel light guide with paired microstructures to produce highly collimated light distribution without using prism films. Each paired microstructure is composed of two different micro-geometries that are placed next to each other...
August 20, 2017: Applied Optics
R M A Azzam
A quarter-wave layer (QWL) of high refractive index, which is deposited on a transparent prism of low refractive index, can be designed to split an incident p-polarized light beam at the Brewster angle (BA) of the air-substrate interface into p-polarized reflected and transmitted beams of equal intensity (50% each) that travel in orthogonal directions. For reflection of p-polarized light at the BA, the supported QWL functions as a free-standing (unsupported) pellicle. An exemplary design is presented that uses SixGe1-x QWL deposited on an IRTRAN1 prism for applications (such as Michelson and Mach-Zehnder interferometry) with a variable compositional fraction x in the 2-6 μm mid-IR spectral range...
August 10, 2017: Applied Optics
Yuan Zhou, Shixun Fan, Yin Chen, Xiaoxia Zhou, Guangcan Liu
Limitations of beam steering in Risley prisms, induced by total internal reflection, are investigated for the four typical configurations. The incident angles at the exit surfaces of double prisms are calculated by nonparaxial ray tracing and compared with the critical angle. On this basis, the limitations of the opening angle, relative orientation of the prisms, and ray deviation power of the system are derived. It is shown that the ray deviation power reaches its extreme value when the opening angles increase to a certain limit value for a given prism material...
August 1, 2017: Applied Optics
Yao Shan, Guohang Hu, Liyuan Gu, Hongbo He, Aijun Zeng, Yuanan Zhao, Anna Sytchkova
A setup for surface-plasmon-resonance- (SPR) based imaging ellipsometry was developed, which gains from the sensitivities of both SPR and ellipsometry to ultrathin film parameters. It is based on Otto's configuration for prism-sample coupling and a wide-beam imaging ellipsometry. A set of ultrathin gold and silver films was measured to determine their optical constants and thicknesses. Coupling the sample using a prism with a convex surface enables us to capture images of generated SPR elliptical fringes, which correspond to different SPR amplitude values at different air gap thicknesses...
October 1, 2017: Applied Optics
Xiao Fu, Fajie Duan, Jiajia Jiang, Tingting Huang, Ling Ma, Changrong Lv
As a special kind of spectrometer with the Czerny-Turner structure, the echelle spectrometer features two-dimensional dispersion, which leads to a complex astigmatic condition. In this work, we propose an optical design of astigmatism-corrected echelle spectrometer using an off-the-shelf cylindrical lens. The mathematical model considering astigmatism introduced by the off-axis mirrors, the echelle grating, and the prism is established. Our solution features simplified calculation and low-cost construction, which is capable of overall compensation of the astigmatism in a wide spectral range (200-600 nm)...
October 1, 2017: Applied Optics
Lei Jing, Yao Wang, Huifu Zhao, Hongliang Ke, Xiaoxun Wang, Qun Gao
In order to meet the requirements of uniform illumination for optical palm/fingerprint instruments and overcome the shortcomings of the poor uniform illumination on the working plane of the optical palm/fingerprint prism, a novel secondary optical lens with a free-form surface, compact structure, and high uniformity is presented in this paper. The design of the secondary optical lens is based on emission properties of the near-infrared light-emitting diode (LED) and basic principles of non-imaging optics, especially considering the impact of the thickness of the prism in the design...
June 10, 2017: Applied Optics
Travis W Sawyer, Kyle S Hawkins, Michael Damento
High-resolution spectrographs extract detailed spectral information of a sample and are frequently used in astronomy, laser-induced breakdown spectroscopy, and Raman spectroscopy. These instruments employ dispersive elements such as prisms and diffraction gratings to spatially separate different wavelengths of light, which are then detected by a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detector array. Precise alignment along the optical axis (focus position) of the detector array is critical to maximize the instrumental resolution; however, traditional approaches of scanning the detector through focus lack a quantitative measure of precision, limiting the repeatability and relying on one's experience...
June 20, 2017: Applied Optics
Cheng Zheng, Qiyuan Li, Gary Rosengarten, Evatt Hawkes, Robert A Taylor
In order to maximize solar energy utilization in a limited space (e.g., rooftops), solar collectors should track the sun. As an alternative to rotational tracking systems, this paper presents a compact, semi-passive beam steering prism array which has been designed, analyzed, and tested for solar applications. The proposed prism array enables a linear concentrator system to remain stationary so that it can integrate with a variety of different solar concentrators, and which should be particularly useful for systems which require a low profile (namely rooftop-mounted systems)...
May 10, 2017: Applied Optics
Joshua S Harvey, Hannah E Smithson, Clive R Siviour, Giles E M Gasper, Sigbjørn O Sønnesyn, Brian K Tanner, Tom C B McLeish
The rainbow has been the subject of discussion across a variety of historical periods and cultures, and numerous optical explanations have been suggested. Here, we further explore the scientific treatise De iride [On the Rainbow] written by Robert Grosseteste in the 13th century. Attempting to account for the shape of the rainbow, Grosseteste bases his explanation on the optical properties of transparent cones, which he claims can give rise to arc-shaped projections through refraction. By stating that atmospheric phenomena are reducible to the geometric optics of a conical prism, the De iride lays out a coherent and testable hypothesis...
July 1, 2017: Applied Optics
Farhad Akbari Afkhami, Ghodrat Mahmoudi, Atash V Gurbanov, Fedor I Zubkov, Fengrui Qu, Arunava Gupta, Damir A Safin
We report the synthesis and structural characterization of a heteroleptic mononuclear discrete complex [Cd(N3)2(L)(MeOH)]·MeOH (1·MeOH) and a one-dimensional coordination polymer of the composition [Cd3(N3)6(L)]n (2), fabricated from Cd(NO3)2·4H2O and the helical organic ligand benzilbis((pyridin-2-yl)methylidenehydrazone) (L) in the presence of two equivalents of NaN3. The formation of different structures is driven by the solvent. The former complex is formed in the presence of MeOH, while the latter complex is formed in EtOH...
October 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Qin Liu, Caixun Bai, Jie Liu, Jiale He, Jianxin Li
A time-division Fourier transform imaging spectropolarimeter (FTISP) for acquiring spatial, spectral, and polarized information is presented. The FTISP employs two ferroelectric liquid crystals (FLCs) and a Wollaston interferometer. The fast axes of the FLCs are controlled to switch quickly without mechanical movement, enabling the polarization state analyzer (PSA) to modulate the full set of Stokes parameters rapidly. The interferometer combines a Wollaston prism with a retroreflector, enabling high interference modulation and facilitating optical alignment...
August 21, 2017: Optics Express
Lan Luo, Xiaodong Qiu, Linguo Xie, Xiong Liu, Zhaoxue Li, Zhiyou Zhang, Jinglei Du
In this paper, a method to improve the precision of prism-coupler-based surface plasmon resonance (SPR) sensors using weak-value amplification (WVA) is presented. A general theory model to describe the post-selected SPR sensing system is established and the polarization-dependent amplitude and phase evolutions induced by the SPR are regarded as the weak interactions in the WVA formalism. As a consequence of WVA, the detected signal can be enhanced with respect to the technical noise which is dependent on the post-selected light intensity...
September 4, 2017: Optics Express
Jicheng Wang, Ci Song, Jing Hang, Zheng-Da Hu, Feng Zhang
A grating-coupled Otto configuration consisting of multilayer films including a few layers of graphene and a germanium prism is proposed. A sharp and sensitive Fano resonance appears when a graphene surface plasmon polaritons (GSPPs) mode from the graphene-dielectric interface couple with the planar waveguide (PWG) mode. We utilize the classical harmonic oscillator (CHO) to explain Fano resonance and study the influence of various parameters of the configuration on the reflection spectra. The highly sensitive sensor can be achieved by introducing detected materials into Otto structure...
October 2, 2017: Optics Express
Fang-Xiang Wang, Wei Chen, Ya-Ping Li, Guo-Wei Zhang, Zhen-Qiang Yin, Shuang Wang, Guang-Can Guo, Zheng-Fu Han
Orbital angular momentum (OAM) is an important resource in high-dimensional quantum information processing, as its quantum number can be infinite. Dove prism (DP) is a most common tool to manipulate OAM light. However, the Dove prism changes the polarization of the photon states and decreases the sorting fidelity of the interferometer. In this work, we analyze the polarization-dependent effect of the DP on OAM light manipulation in the normal single-path Sagnac interferometers (SPSIs) with beam splitter (BS) and polarizing beam splitter (PBS)...
October 16, 2017: Optics Express
Li Jiu-Sheng
We present a terahertz wave switch utilizing Kretschmann configuration which consists of high-refractive-index prism-liquid crystal-periodically grooved metal grating. The switching mechanism of the terahertz switch is based on spoof surface plasmon polariton (SSPP) excitation in the attenuated total reflection regime by changing the liquid crystal refractive index. The results highlighted the fact that the feasibility to "tune" the attenuated total reflection terahertz wave intensity by using the external applied bias voltage...
August 7, 2017: Optics Express
C D Polyzou, E S Koumousi, Z G Lada, C P Raptopoulou, V Psycharis, M Rouzières, A C Tsipis, C Mathonière, R Clérac, S P Perlepes
The use of 2-pyridinealdoxime (paoH), methyl 2-pyridyl ketone oxime (mepaoH), phenyl 2-pyridyl ketone oxime (phpaoH) and pyridine-2-amidoxime (NH2paoH) for the synthesis of dinuclear Co(III)/Dy(III) complexes is described in the absence or presence of an external base. Complexes [CoDy(pao)3(NO3)3] (1), [CoDy(mepao)3(NO3)3] (2), [CoDy(phpao)3(NO3)3] (3) and [CoDy(NH2pao)3(NO3)3]·3MeOH (4·3MeOH) have been isolated and their structures have been determined by single-crystal X-ray crystallography. The complexes crystallize in non-centrosymmetric (2, 3) or centrosymmetric (1, 4·3MeOH) trigonal space groups and form a family of triply-oximate bridged dinuclear Co(iii)-Dy(iii) complexes...
October 17, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Rosa Maza-Quiroga, Nuria García-Marchena, Pablo Romero-Sanchiz, Vicente Barrios, María Pedraz, Antonia Serrano, Raquel Nogueira-Arjona, Juan Jesus Ruiz, Maribel Soria, Rafael Campos, Julie Ann Chowen, Jesus Argente, Marta Torrens, Meritxell López-Gallardo, Eva María Marco, Fernando Rodríguez de Fonseca, Francisco Javier Pavón, Pedro Araos
BACKGROUND: Cocaine use disorder (CUD) is a complex health condition, especially when it is accompanied by comorbid psychiatric disorders (dual diagnosis). Dual diagnosis is associated with difficulties in the stratification and treatment of patients. One of the major challenges in clinical practice of addiction psychiatry is the lack of objective biological markers that indicate the degree of consumption, severity of addiction, level of toxicity and response to treatment in patients with CUD...
2017: PeerJ
Sheela Joseph, Rajinikanth Janakiraman, Geeta Chacko, Rama Jayaraj, Mahiban Thomas, Meera Thomas, Sramana Mukhopadhyay
OBJECTIVES: Treatment failure and poor 5-year survival in mucosal head and neck squamous cell carcinoma (HNSCC) has remained unchanged for decades mainly due to advanced stage of presentation and high rates of recurrence. Incomplete surgical removal of the tumour, attributed to lack of reliable methods to delineate the surgical margins, is a major cause of disease recurrence. The predictability of recurrence using immunohistochemistry (IHC) to delineate surgical margins (PRISM) in mucosal HNSCC study aims to redefine margin status by identifying the true extent of the tumour at the molecular level by performing IHC with molecular markers, eukaryotic initiation factor, eIF4Eand tumour suppressor gene, p53, on the surgical margins and test the use of Lugol's iodine and fluorescence visualisation prior to the wide local excision...
October 15, 2017: BMJ Open
James Babington
We consider how optical propagation and aberrations of freeform systems can be formulated in phase space. As an example system, a freeform prism is analyzed and discussed. Symmetry considerations and their group theory descriptions are given some importance. Numerical aberrations are also highlighted and put into the context of the underlying aberration theory.
June 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
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