Set Of Mirrors Research Articles

Development and field tests of a narrowband all-reflective spatial heterodyne spectrometer.

We describe the design, development, and performance of a narrowband, all-reflective, unaliased spatial heterodyne spectrometer (SHS) that has been tested in observations at the focus of the 1.6m main telescope of the McMath-Pierce solar telescope on Kitt Peak. The all-reflective SHS described herein is a highly robust common-path Fourier transform spectrometer without moving parts that, over a limited spectral region, combines the large field of view and high resolving power characteristic of interference spectrometers but at substantially reduced instrument size and optical tolerances. The self-scanned region of wavelength space and resolving power of the SHS are determined by the beam size, the diffraction grating groove density, the number of detector elements, and the fixed orientation of a set of pilot mirrors. The results presented here represent the first successful implementation of this reflective SHS design for field use. We discuss concepts behind the unaliased reflective SHS design and report the performance of the instrument when used to observe terrestrial airglow and absorption features, the solar spectrum, and the Jovian spectrum near λ=6300 Å, at the achieved resolving power (R=λ/δλ) of R>100,000. The results confirm that reflective SHS instruments can deliver effective interferometric performance in the visible to the far-ultraviolet wavelengths with commercial optics of moderate surface quality.

Using microcontrollers for orienting a set of mirrors to focus the light beam

This paper presents an independent control system for two mirrors tracking the position of the sun and allowing the focalisation of sunlight to increase the efficiency of the energy conversion process.The application is designed to operate on the principle of a master that controls slave devices. The mirrors are designed to be independently manoeuvrable, this being possible by using microcontrollers to handle the management of their local orientation. For orienting a surface in order to capture or reflect the solar radiation, it is necessary to know the sunlight direction with a very high accuracy.

Design of a Low Power Current Steering Digital to Analog Converter in CMOS

In this paper it deals with the design & analysis of a 16-bit current steering digital-to-analog converter. The digital-to-analog converter contained eight sets of current mirrors with different weight. The digital-to-analog converter was implemented using GDI Technology (Gate Diffusion Input) in CMOS process. The average INL and DNL are 0.27 LSB and 0.32 LSB, respectively. At the sample rate of 350 MHz and supply voltage of 3.5 V, the DAC consumed about 66.903 nW. The SFDR was -37 dB. The digital-to-analog converter of this construction consumed less power and chip area. It is suitable for portable device application. . The proposed circuit design simulation can be done using NI- Multisim 13.0 software.

Biofunctionalized all-polymer photonic lab on a chip with integrated solid-state light emitter

A photonic lab on a chip (PhLOC), comprising a solid-state light emitter (SSLE) aligned with a biofunctionalized optofluidic multiple internal reflection (MIR) system, is presented. The SSLE is obtained by filling a microfluidic structure with a phenyltrimethoxysilane (PhTMOS) aqueous sol solution containing a fluorophore organic dye. After curing, the resulting xerogel solid structure retains the emitting properties of the fluorophore, which is evenly distributed in the xerogel matrix. Photostability studies demonstrate that after a total dose (at λ=365 nm) greater than 24 J cm−2, the xerogel emission decay is only 4.1%. To re-direct the emitted light, the SSLE includes two sets of air mirrors that surround the xerogel. Emission mapping of the SSLE demonstrates that alignment variations of 150 µm (between the SSLE and the external pumping light source) provide fluctuations in emitted light smaller than 5%. After this verification, the SSLE is monolithically implemented with a MIR, forming the PhLOC. Its performance is assessed by measuring quinolone yellow, obtaining a limit of detection (LOD) of (0.60±0.01) µM. Finally, the MIR is selectively biofunctionalized with horseradish peroxidase (HRP) for the detection of hydrogen peroxide (H2O2) target analyte, obtaining a LOD of (0.7±0.1) µM for H2O2, confirming, for the first time, that solid-state xerogel-based emitters can be massively implemented in biofunctionalized PhLOCs.

Beam propagation and stray radiation in the ITER EC H&CD Upper Launcher

The four ITER Electron Cyclotron Upper Launchers (UL) are designed to control Magneto- Hydrodynamic instabilities with the deposition of Electron Cyclotron power. According to the present design, each launcher comprises two rows of four input waveguides, whose output beam is focused and driven towards the plasma by four sets of mirrors. In order to study the beam-launcher interaction throughout quasi-optical propagation, with particular attention to straylight behaviour, and to verify analytical calculations, a 3D model of the UL optical system has been implemented with the electromagnetic code GRASP® and the Physical Optics method. Detailed description of the components are introduced: pure hybrid mode HE11 from cylindrical waveguide as input beams, real shapes of the mirror contours, semi-analytical description of the ellipsoidal surfaces of focussing mirrors. A conceptual calculation scheme has been developed in order to take into account not only the direct contribution of the single source on its next scatterer but also the first order indirect effects: crosstalk from different lines of the same row and crosstalk from different rows have been evaluated after reflection on the first and third set of mirrors. The evaluations presented have been performed on the preliminary UL design, the last major milestone before finalization; however, the numerical model is suitable to be applied to future evolutions of the setup and/or other configurations.

Design study of a wide-angle infrared thermography and visible observation diagnostic on JT-60SA

AbstractDesign study of a wide-angle infrared (IR) thermography (surface temperature measurement) and visible observation diagnostics for JT-60SA are reported. The new design offers an optical solution without a “blind spot” which is one of the advantages. In order to image a large section inside the vacuum vessel (both in poloidal and toroidal directions), the optical system of endoscope is to provide a wide-angle view in the IR and visible wavelength ranges. The estimated IR optical spatial resolution is approximately 2cm at a distance of 7.6m from the front optics with a pupil diameter of 4mm. For a surface temperature measurement it would be larger (∼4cm for a surface temperature error less than 5%). The optics of this system can be divided into three parts: (1) a mirror based optical head (two set of spherical mirrors plus two flat mirrors) that produces an intermediate image, (2) a Cassegrain telescope system, and (3) a relay group of lenses, being adapted to the two kinds of detectors for IR and visible observations.

Observations of atmospheric water vapor, aerosol, and cloud with a Raman lidar

To realize the improvement of signal-to-noise ratio and rejection rate for elastic Mie-Rayleigh signals, a set of dichroic mirrors and narrow-band interference filters with high efficiency was proposed to constitute a new spectroscopy for atmospheric water vapor, aerosol, and cloud studies. Based on the curves of signal-to-noise ratio at three different channels, the actual rejection rates of elastic Mie-Rayleigh signals at the Raman channels were found to be higher than eight orders of magnitude with the cloudy conditions. Continuous nighttime observations showed that the statistical error of the water vapor mixing ratio was <10% at a height of 2.3 km with an aerosol backscatter ratio of 17. Temporal variations of water vapor and aerosols were obtained under the conditions of cloud and cloud-free, the change relevance between aerosol and water vapor was analyzed, and the growth characteristics of water vapor and aerosols showed a good agreement within the cloud layers. Obtained results indicate achievement of the continuous detection of water vapor, aerosol, and cloud with a high efficiency and stability by Raman lidar.

A novel 3D/dichoptic presentation system compatible with large field eye tracking

Traditional 3D and dichoptic presentation system usually uses a mirror stereoscope with a set of prisms and mirrors or colored glasses (red-green glasses) to split the view of the eyes looking at a computer display. Although these types of setups are useful in varieties of psychophysical and neuroscience studies, they have limitations. The colored glasses usually have a noticeable leak between the eyes. They also have a binocular rivalry effect over the visual field. Color glasses are hard to use for people with color deficits. Naïve subjects and clinical populations with visual impairment usually have a hard time to fuse with the mirror-prism setup. More importantly, the mirror stereoscope with a standard computer display usually does not provide a viewing angle that is big enough for a reliable measurement of fast and continuous eye movements over a large field. It is also insufficient for experiments examining visual motion and eye movements, for which it is crucial that the observers should not see the external reference frame, such as the edges of the mirrors. Although a projection system with a large screen and the active shutter glasses can provide a large viewing field, the active shutters can cause a 50% loss of the eye-tracking data. The presentation and eye-tracking system that we have developed can offer the following functions in one integrated setup: 1) No interruption of the eye tracking signals that currently occurs with active shutter glasses; 2) Large-field presentation, necessary for reliable measurement of the eye movement over a wide range of speeds and over a large distance; 3) Natural viewing experience like in movie theaters, which is important for reliable measurement in naive observers. The system is affordable and portable (except the screen), and can serve as part of other research setups, such as human brain imaging instruments. Meeting abstract presented at VSS 2014

Multispectral Stereoscopic Imaging Device: Simultaneous Multiview Imaging From the Visible to the Near-Infrared

We have designed a hand-held imaging device which is capable of capturing images of multiple spectral bands, spanning the visible to the near-infrared, as well as imaging multiple perspective views of an object simultaneously on one detector. This concept utilizes a set of mirrors positioned obliquely to the principle axis of the imaging device that present different perspective views, of a target, and simultaneously bandpass filters those views before the light enters the device. In its current state, our instrument is capable of simultaneously imaging nine independent spectral bands and three different perspective views. The device allows for measurement of multispectral properties of different material enabling multispectroscopic science as demonstrated by studying the separability of four types of black ink. Exploiting the stereoscopic imaging capability of the device, we are able to construct 3-D surface features of a target.

High-power, continuous-wave, solid-state, single-frequency, tunable source for the ultraviolet.

We report the development of a compact, high-power, continuous-wave, single-frequency, ultraviolet (UV) source with extended wavelength tunability. The device is based on single-pass, intracavity, second-harmonic-generation (SHG) of the signal radiation of a singly resonant optical parametric oscillator (SRO) working in the visible and near-IR wavelength range. The SRO is pumped in the green with a 25-mm-long, multigrating, MgO doped periodically poled stoichiometric lithium tantalate (MgO:sPPLT) as nonlinear crystal. Using three grating periods, 8.5, 9.0, and 9.5μm of the MgO:sPPLT crystal and a single set of cavity mirrors, the SRO can be tuned continuously across 710.7-836.3nm in the signal and corresponding idler across 2115.8-1462.1nm with maximum idler power of 1.9W and maximum out-coupled signal power of 254mW. By frequency-doubling the intracavity signal with a 5-mm-long bismuth borate (BIBO) crystal, we can further tune the SRO continuously over 62.8nm across 355.4-418.2nm in the UV with maximum single-frequency UV power, as much as 770mW at 398.28nm in a Gaussian beam profile. The UV radiation has an instantaneous line-width of ∼14.5 MHz and peak-peak frequency stability of 151MHz over 100s. More than 95% of the tuning range provides UV power >260 mW. Access to lower UV wavelengths can in principle be realized by operating the SRO in the visible using shorter grating periods.

Progress of the ECRH Upper Launcher design for ITER

The design of the ITER ECRH system provides 20MW millimeter wave power for central plasma heating and MHD stabilization. The system consists of an array of 24 gyrotrons with power supplies coupled to a set of transmission lines guiding the beams to the four upper and the equatorial launcher. The front steering upper launcher design described herein has passed successfully the preliminary design review, and it is presently in the final design stage. The launcher consists of a millimeter wave system and steering mechanism with neutron shielding integrated into an upper port plug with the plasma facing blanket shield module (in-vessel) and a set of ex-vessel waveguides connecting the launcher to the transmission lines.Part of the transmission lines are the ultra-low loss CVD torus diamond windows and a shutter valve, a miter bend section and the feedthroughs integrated in the plug closure plate. These components are connected by corrugated waveguides and form together the first confinement system (FCS). In-vessel, the millimeter-wave system includes a quasi-optical beam propagation system including four mirror sets and a front steering mirror. The millimeter wave system is integrated into a specifically optimized upper port plug providing structural stability to withstand plasma disruption forces and the high heat load from the plasma side with a dedicated blanket shield module. A recent update in the ITER interface definition has resulted in the recession of the upper port plug first wall panels, which is now integrated into the design. Apart from the millimeter wave system the upper port plug houses also a set of shield blocks which provide neutron shielding. An overview of the actual ITER ECRH Upper Launcher is given together with some highlights of the design.

Theoretical and experimental studies of broadband phase-controlled attosecond mirrors

We present procedures to develop and characterise chirped multilayer mirrors for attosecond pulses. The design procedure involves a simulated annealing optimisation algorithm to obtain a multilayer structure with the desired performances. The characterisation step requires the use of well-calibrated attosecond and synchrotron beam lines, allowing one to measure the amplitude and phase response of the mirror. We illustrate these approaches with a set of mirrors designed to have zero or negative dispersion. The remarkable agreement between theoretical and experimental performances validates this overall process, and demonstrates the capability of such mirrors to control the temporal profile of attosecond pulses. These tools and techniques for developing attosecond chirped mirrors will facilitate the generalisation of such components on attosecond experiments.

非链式脉冲DF激光器非稳腔设计与实验研究

By employing positive branch confocal unstable resonator, design of cavity parameters and experimental research on non-chain pulsed DF laser are carried out. The advantages of suppressing divergence angle and improving beam quality are shown by comparing plano-concave stable resonator with unstable resonator. To estimate the beam quality, diffraction limit magnification is chosen as evaluating criterion, which can incarnate both the energy focusing degree and divergence angle excursion. 86.5% enveloping energy is used to define spot size, and 90-10 knife edge method is adopted to measure it. Nine sets of mirrors with different magnifications and mode volumes are tested and compared, and optimization method of unstable cavity parameters is concluded. Taking energy, divergence and diffraction limit magnification into account, the optimal parameters are M=1.89, D=40 mm. Laser beam with divergence angle of 0.74 mrad, =1.35, laser energy of 1.86 J, and peak power of 16.4 MW is obtained at these parameters.

«СМЕЛОСТЬ ИЗОБРЕТЕНИЯ» В РОМАНЕ М. Ю. ЛЕРМОНТОВА «ГЕРОЙ НАШЕГО ВРЕМЕНИ»

In the history of Russian and world literature, Lermontov's novel A Hero of Our Time stands as an original development of Pushkin's discoveries in genre, bringing the new variable of ?historicity? into the traditional domains of the novel “fictions of love adventures” and ?private life?. Using the famous dictum by Pushkin, we can say that the conceptual design of A Hero of Our Time features the “higher boldness: the boldness of invention” the hallmark of a work of genius which sets it apart from the commonplace. By means of unique compositional choices and a juxtaposition of contrasting viewpoints, controversial remarks and actions of his characters, Lermontov has created a “set of mirrors” facing each other. Every story and novella, the preface to Pechorin's diary and to the second edition of the novel reflect one another, setting up an endless semantic vista. The protagonist is shown to be inexhaustible, personality proved boundless, an thus the reader's recognition becomes endless. We can denounce the protagonist as much as we want, but his own judgement of himself will always remain the harshest. In Lermontov's novel, words have a second, hidden semantics. They mean more than is actually said, or sometimes not quite what is being said. The protagonist is bigger than words and higher than others' opinions of him. He is a riddle, solved and impenetrable at the same time. The concept of the genre as developed by Lermontov built on the artistic discoveries of Pushkin and the theoretical ideas of A. I. Galich, N. I. Nadezhdin and V. G. Belinsky, anticipating the novels by Dostoevsky and Tolstoy. In suggesting his unique understanding of the genre, Bakhtin did not describe the novel as it was, but showed it as it might be, revealing its limitless artistic capabilities. A Hero of Our Time is among the few exceptions which justify Bakhtin's hypothesis of the novel of the new time as a new genre of world literature.

Alignment Method of Segmented Primary Mirror for the Solar Concentrator in Temixco-México, Using Optical Technique

This paper is focused on the alignment of panels that conform the primary mirror of the solar furnace of high radiative flux (HFSF) using geometrical optics with an arrangement similar to that of the Ronchi test but without the grid. Considering the optical design of the HFSF which involves 409 hexagonal mirror facets, grouped in 5 sets according to their focal length. The general idea is to align each section separately, taking advantage of the different curvature radii. A quasi-point source is placed near in the center of curvature of one of the set of mirrors to be aligned, and the divergent light coming from the source illuminates the whole region of the concentrator. Then, the light directed to the region under consideration is reflected by the group of mirrors and the reflection from each mirror forms a separated image over an observation screen. In this screen, the actual image of the source is compared to the theoretical image, using a previously produced map of their positions, by means of ray trace software. The alignment procedure consists on forcing the real image to coincide with that expected from the computation, by rotating the mirror around its supporting point.

胶层固化对反射镜面形影响的仿真与试验

The effect of shrinkage stress induced by adhesive curing on a reflective mirror surface was analyzed when the thick adhesive layer was used to joint optical elements. Firstly, the principle of tensile stress induced by adhesive layer to optical elements during adhesive curing was analyzed and the main factors of generating shrinkage stress were obtained. Then, a finite element model of the reflective mirror set was constructed. The finite element analysis was carried out by using the thermal-to-shrinkage analogy and the thermal modeling tools were used to compute the adhesive curing shrinkage. The curing shrinkage was substituted by low temperature concentration, but the Coefficient of Thermal Expansion( CTE) value of the adhesive could not be taken place by the coefficient of adhesive shrinkage directly. After converting the coefficient of adhesive shrinkage to the equivalent CTE value, the analysis results are accord with the test results. Finally, the improved glue scheme was put forward on the basis of the analysis results. The experiment results indicate that the reflective mirror surface deformation( PV value) has decreased from 0.547 to 0.064, and the RMS value decreased from 0.127 to 0.038. This results mean that the effect of shrinkage stress in adhesive curing processing on the reflective mirror surface has improved greatly.

Designing illuminating devices with faceted reflectors

One approach for increasing the structural homogeneity of light distribution is to use an illuminating device with a mirror reflector whose surface consists of a set of elementary plane mirrors, called facets. We present a clear graphical method for optimal faceting of reflectors with a point or spherical source.

Retractable tube design issues in ITER CXRS UPP #3

The retractable tube is located in the upper port plug #3 of ITER core charge exchange recombination spectroscopy (cCXRS), where it is surrounded by a set of mirrors, diagnostic shielding module (DSM), outer shell, cleaning device and shutter. Accordingly to the recent port plug concept the tube is an optional unit that carries the cleaning system of the first mirror. The cleaning device shall be a compact instrument at the tube head that influences the tube diameter primarily. Independently of the cleaning device the tube cooling channels and its proper support concept has to be developed.Various manufacturing methods are investigated for the proper layout of the tube cooling structure. They are the gun-drilled deep holes, the solid state bonded sheets forming cooling channels between the welded layers, ‘tube-in-tube’ approach. Most of them were analyzed in view of their thermal conditions.The tube support system design is a complex task, that has to take into account several boundary conditions and limitations. The tube must be compatible with the assumed ITER generic installation procedure, withstand the electromagnetic (EM) and thermal loads. Furthermore, the tube has to be exchanged several times during its lifetime.The paper summarizes the tube cooling layout possibilities and the assumptions on its support concepts.

Real-time mirror steering for improved closed loop neoclassical tearing mode suppression by electron cyclotron current drive in DIII-D

The development and operation of the neoclassical tearing mode (NTM) avoidance and control system for DIII-D, which uses six sets of real-time steerable mirrors in order to move the electron cyclotron current drive (ECCD) deposition location in plasma, is described. The real-time DIII-D NTM control algorithm residing in the Plasma Control System (PCS) automatically detects an NTM by analysis of the Mirnov diagnostics, employs motional Stark effect (MSE) EFIT MHD equilibrium reconstruction to locate the rational q-surface where the NTM island can be found, then calculates the appropriate mirror position for alignment of the ECCD with the island using ray tracing. The control commands from PCS are sent to the electron cyclotron system to switch on and off or modulate the gyrotrons and to the steerable mirror system to move the steerable mirrors to the requested positions. Successful NTM suppression has been achieved in DIII-D using this control system to rapidly align the NTM island and the ECCD deposition location, and to actively maintain the alignment as plasma conditions change.

Predicted optical performance of the GM/CA@APS micro-focus beamline

GM/CA at the APS has developed microcrystallography capabilities for structural biology applications. The robust, quad, mini-beam collimators, which enable users to rapidly select between a 5, 10 or 20 micron diameter beam or a scatter guard for the full focused beam, are coupled with several powerful automated software tools that are built into the beamline control system JBluIce-EPICS. Recent successes at beamlines around the world in solving structures from microcrystals (2 – 10 microns) have led to increased demand for high-intensity micro-focus beams. We have designed a new micro-focus endstation to increase the intensity in mini- and micro-beams at GM/CA by one to two orders of magnitude to meet this growing demand. The new optical design is based on the well-established approach of using two-stage demagnification. The existing bimorph mirrors, arranged in a Kirkpatrick-Baez geometry, focus the beam onto slits located upstream of the sample whereby the slit aperture defines a secondary source, that is reimaged with a second pair of mirrors. This design incorporates two focal modes: a mini-beam mode where the beam is focused to 20-micron diameter and a micro-beam mode where it is focused to 5-microns. The size of the secondary source aperture can be varied rapidly (seconds) to adjust the beam size at the sample position in two ranges 20 – 3 micron and 5 – 1 micron. The second set of mirrors will each have two super polished ellipses allowing quick (minutes) interchange between modes.