Mirror Unit Research Articles

Portable and Battery-Powered PCR Device for DNA Amplification and Fluorescence Detection.

Polymerase chain reaction (PCR) is a technique for nucleic acid amplification, which has been widely used in molecular biology. Owing to the limitations such as large size, high power consumption, and complicated operation, PCR is only used in hospitals or research institutions. To meet the requirements of portable applications, we developed a fast, battery-powered, portable device for PCR amplification and end-point detection. The device consisted of a PCR thermal control system, PCR reaction chip, and fluorescence detection system. The PCR thermal control system was formed by a thermal control chip and external drive circuits. Thin-film heaters and resistance temperature detectors (RTDs) were fabricated on the thermal control chip and were regulated with external drive circuits. The average heating rate was 32 °C/s and the average cooling rate was 7.5 °C/s. The disposable reaction chips were fabricated using a silicon substrate, silicone rubber, and quartz plate. The fluorescence detection system consisted a complementary metal-oxide-semiconductor (CMOS) camera, an LED, and mirror units. The device was driven by a 24 V Li-ion battery. We amplified HPV16E6 genomic DNA using our device and achieved satisfactory results.

A Method for the Installation Measurement and Alignment of a Mirror Unit in the Solar Dish Concentrator

The mirror unit installation error of the solar parabolic dish concentrator can adversely affect its optical performance causing optical intercept losses and hot spots on the absorber surface, which in turn affect safety. Thus, minimizing mirror installation error is considered very important. In this paper, a new method for the facet installation measurement and facet alignment of the mirror unit in the dish concentrator is presented. Firstly, a “clean” facet installation error measurement method using photogrammetry is presented. The photogrammetry measures the spatial coordinates of three feature points to reverse the mirror facet alignment error parameters. Next, two novel methods, a three-rotation alignment method and two-rotation alignment method for aligning the mirror facet are presented and corresponding mathematical models. The advantage of these alignment methods is that the adjustment value and order for each support bolt can be determined before the mirror facet is aligned, which could provide quantitative adjustment information to operator and avoid repeated adjustments. Finally, validity of the installation measurement and facet alignment method was verified by a numerical simulation and an experiment using a metal facet alignment. The presented methods do not rely on the geometry of the reflector mirror and could therefore have extensive uses in applications such solar tower and trough concentrator.

A five-axis parallel kinematic mirror unit for soft X-ray beamlines at MAX IV

With the introduction of the multi-bend achromats in the new fourth-generation storage rings the emittance has decreased by an order of magnitude resulting in increased brightness. However, the higher brightness comes with smaller beam sizes and narrower radiation cones. As a consequence, the requirements on mechanical stability regarding the beamline components increases. Here an innovative five-axis parallel kinematic mirror unit for use with soft X-ray beamlines using off-axis grazing-incidence optics is presented. Using simulations and measurements from the HIPPIE beamline at the MAX IV Laboratory it is shown that it has no Eigen frequencies below 90 Hz. Its positioning accuracy is better than 25 nm linearly and 17-35 µrad angularly depending on the mirror chamber dimensions.

Morphology and orientated growth of second-phase precipitates in a Eu2+-doped equimolar KCl:KBr solid solution: an epifluorescence microscopy study by using the doping ion as a fluorochrome.

The shape and orientation of second-phase precipitates in a Eu2+-doped equimolar KCl:KBr solid solution are reported in this paper as they were unveiled by epifluorescence microscopy. To make this, microscopy images of different optical cross sections of some precipitate fields and, also, of some representative precipitates in these fields, were recorded by using the Eu2+ ion itself as a fluorochrome. From these images, the corresponding precipitate fields and individual precipitates were electronically reconstructed into the host lattice space. Previously, the KCl:KBr:Eu2+ system was characterized by absorption and fluorescence optical spectrophotometry, to tailor properly the fluorescence mirror unit, as well as by powder and single-plate X-ray diffraction, to correlate the host lattice orientation with those of the observed precipitates. These are shaped as plates, with broad faces parallel to host lattice {100}, {110} or {120}planes (the {100}, {110} and {120} precipitates, respectively), and as rods, aligned with a host lattice ˂100> direction (the ˂100> precipitates). The {100}, {110}, {120}-precipitate broad faces are in the shapes of 72.6° rhomboids, rectangles and 59.5° rhomboids, with a side lying along host lattice <310>, <110> and <421> directions, respectively, and with another side lying along a <100> direction. A typical precipitate field and the spatial reconstructions of typical {100}, {110}, {120} and ˂100> precipitates, as well as their corresponding electronic 3D-geometrical models, are described in detail. It is discussed that four different europium precipitation states are responsible for the precipitation and that the precipitate lattices are spatially coherent with the host lattice.

Composite polarization conversion metasurface and its application in integrated regulation radiation and scattering of antenna

The transmission polarization conversion metasurface has been widely concerned, because it has the advantage of being easy to be conformal with the antenna. Based on the reasonable arrangement of transmission polarization conversion units, various and complex electromagnetic functions can be realized. As the electromagnetic open window on the flight platform, the antenna is the bottleneck that restricts the decrease of radar cross section (RCS) of the whole flight platform. It is difficult to simultaneously realize the normal and efficient radiation of the antenna and the decrease of the RCS of the antenna. When the designed transmission metasurface is used in the antenna design, the radiation and scattering of the antenna can be regulated comprehensively. In this paper, a composite polarization conversion metasurface is proposed and verified. The unit cell of composite polarization conversion metasurface consists of two mirror symmetrical anisotropic metal patches in the upper layer, a dielectric layer and a polarization gate in the lower layer. When the polarization direction of the incident electromagnetic wave is perpendicular to the extension direction of the polarization gate and arrives at the composite polarization conversion surface, the conversion surface can realize the conversion from transmission linear polarization to right-hand circular polarization in a frequency range from 9.3 GHz to 10.9 GHz. When the polarization direction of the incident electromagnetic wave is parallel to the extension direction of the polarization gate, co-polarized total reflection can be realized. The chessboard arrangement metasurface is composed of composite polarization conversion unit and its mirror unit. A novel linearly polarized chessboard arrangement metasurface antenna is composed of the linearly polarized source microstrip antenna with a bandwidth of 9.4–10.7 GHz and the chessboard arrangement metasurface. By using the counter rotating cancellation characteristic of circular polarization, the chessboard arrangement metasurface antenna maintains linearly polarized radiation. Comparing with the source microstrip antenna, the linear polarization purity of chessboard arrangement metasurface antenna is improved from 9.5 GHz to 10.5 GHz. At the same time, the forward gain of the chessboard arrangement antenna increases and the radar cross section decreases. The maximum reduction is 39.2 dB. To further verify the practicability of the design and analysis, the chessboard arrangement metasurface antenna sample is fabricated and measured in microwave anechoic chamber with an Agilent 5230C network analyzer. The experimental results are in good agreement with the simulation results. This study has important reference value in the design of high gain, low RCS antenna and integrated regulation radiation and scattering of antenna.

A Low-RCS, High-GBP Fabry–Perot Antenna With Embedded Chessboard Polarization Conversion Metasurface

A Fabry-Perot (FP) antenna with high gain-bandwidth product (GBP) and wideband radar cross section (RCS) reduction is proposed using an embedded chessboard polarization conversion metasurface (CPCM). A polarization conversion metasurface (PCM) unit and its mirror unit are etched on both sides of a dielectric substrate with chessboard arrangement to form a CPCM. The in-band and out-of-band low-RCS features of the FP antenna are realized by destructive interference, and the high GBP is attributed to the FP resonant cavity. Moreover, an additional small CPCM designed for another PCM unit is embedded into the original CPCM to construct an embedded CPCM, which helps to improve in-band RCS reduction and has a positive effect on gain enhancement and 10-dB impedance bandwidth. The measured results show that the FP antenna with embedded CPCM has a 10-dB return-loss bandwidth of 8.48-12.21 GHz (36.1%), a GBP of 1338, a 3-dB gain bandwidth of 8.9-11.5 GHz (25.5%) and a maximum realized gain of 17.2 dBi. Meanwhile, the measured RCS reduction band covers 8-26 GHz (105.9%) with a peak RCS reduction of 21.2 dB at 9.4 GHz.

Design of a wideband polarisation conversion metasurface and its application for RCS reduction and gain enhancement of a circularly polarised antenna

An improved loading method of checkerboard-based linear polarisation conversion metasurface (PCM) is proposed for gain enhancement and wideband radar cross-section (RCS) reduction of the circularly polarised patch antenna (CPA). The proposed metasurface consists of a checkerboard arrangement of PCM and its mirror unit cells, and an improved loading method is used to rearrange the PCM unit cells around the radiating patch. The PCM unit cell is composed of a metallic pattern on the top and bottom surface covered with metal. A wideband RCS reduction is realised by achieving 180° cross-polarisation reflection phase difference between the two neighbouring PCM unit cells and gain enhancement is achieved by the coherent superposition of energy in the far-field between the radiating patch and PCM cells. Simulated and measured results depict that the operating bandwidth of CPA and the proposed antenna is 12.6-13.76 GHz. The peak gain of the proposed antenna is 3.5 dB higher than the CPA and 3-dB axial ratio bandwidth of the designed antenna is 200 MHz. The proposed antenna achieves significant RCS reduction in the frequency range of 9.6-22.6 GHz with maximum in-band RCS reduction of 21 dB and maximum out of band RCS reduction of 34 dB.

Bayesian modeling of microwave radiometer calibration on the example of the Wendelstein 7-X electron cyclotron emission diagnostic.

This paper reports about a novel approach to the absolute intensity calibration of an electron cyclotron emission (ECE) spectroscopy system. Typically, an ECE radiometer consists of tens of separated frequency channels corresponding to different plasma locations. An absolute calibration of the overall diagnostic including near plasma optics and transmission line is achieved with blackbody sources at LN2 temperature and room temperature via a hot/cold calibration mirror unit. As the thermal emission of the calibration source is typically a few thousand times lower than the receiver noise temperature, coherent averaging over several hours is required to get a sufficient signal to noise ratio. A forward model suitable for any radiometer calibration using the hot/cold method and a periodic switch between them has been developed and used to extract the voltage difference between the hot and cold temperature source via Bayesian analysis. In contrast to the classical analysis which evaluates only the reference temperatures, the forward model takes into account intermediate effective temperatures caused by the finite beam width and thus uses all available data optimally. This allows the evaluation of weak channels where a classical analysis would not be feasible, is statistically rigorous, and provides a measurement of the beam width. By using a variance scaling factor, a model sensitive adaptation of the absolute uncertainties can be implemented, which will be used for the combined diagnostic Bayesian modeling analysis.

Estimation of neutral fluxes on the first mirror of H-alpha diagnostics in ITER

The first mirrors of all optical diagnostics in ITER will be exposed to the fluxes of neutrals, mainly D, T and Be. This can lead to formation of erosion and deposition zones on the mirror surface. In this work, the fluxes of neutral D, T and Be on the first mirror of H-alpha diagnostics in the equatorial ports were analyzed with Zemax OpticStudio software. Only stationary modes of ITER were considered. The geometry of viewing cutouts in diagnostic shielding modules (DSM) and the model of the first mirror units (FMU) were taken from the ENOVIA database. It is shown that the net erosion is dominating in major part of the first mirror zone with erosion rate ≈100 nm/year. The net deposition zone is located on the edges of the mirror, where deposition rate reaches up to 900 nm/year. Being made of single crystal molybdenum, the mirrors will keep their optical properties under erosion over the whole ITER lifetime. The contaminated edges are not important for the light collection and imaging of the SOL emission in the areas of interest at the ITER first wall within the selected field-of-view. The DC plasma discharge mirror cleaning system will be used to recover FM performance in case of eventual contamination.

Testing of the optical chain mockup of H-alpha and Visible Spectroscopy for ITER

H-alpha and Visible Spectroscopy is one of the ITER first-plasma diagnostics providing full poloidal coverage of plasma scrape-off layer near the first wall. There are two poloidal-view channels in Equatorial Port Plug 11 (EPP11), one tangential-view channel in Equatorial Port Plug 12 (EPP12), and one divertor-view channel in Upper Port Plug 02 (UPP02). At the moment, the final design phase is ongoing, requiring proper testing of design solutions to identify the realistic optical parameters and the problems related to the manufacturing, alignment, calibration and stability issues. A full-scale mockup of the whole optical chain has been built for this purpose. It comprises the most important units starting from the in-vessel optical front-end (First Mirror Unit) to the Interspace relay optics (Long-Focus Spectral Telescope), and to the Optical Bench Assembly located in the Port Cell, where the collected light is coupled to the imaging cameras and to the complex optical fiber bundle transmitting it to the various detectors and spectrometers to be located in the ITER Diagnostic Building. The detailed optical design, analyses, benchmarking and test results are reported with a main focus on the alignment/calibration issues, and on the spatial resolution measured. The measurements have been performed in the wide spectral range 450–700 nm, which is required for the monitoring of the H-alpha, Beryllium and other impurity emission line profiles with probable local peaks considered as the most important ITER safety-relevant task for the passive visible spectroscopy diagnostics.

Cost estimation relationships of a small scale linear Fresnel reflector

This paper presents a cost estimating relationship (CER) of a novel small scale linear Fresnel reflector (SSLFR). The CER has been developed analyzing in detail the manufacturing processes of the SSLFR, its parameters, and the possible sub-components. As a result of this analysis, the SSLFR has been divided into 8 sub-components: fixed and mobile structures, movement units, mirror units, secondary reflector system, tracking system, assembly, and foundation. These sub-components are described in detail and designed using Autodesk Inventor, specifying manufacturing materials and processes. The study includes a full stress analysis of the sub-components, considering self weight, snow loads, and wind loads. For each sub-component an estimate of the primary costs is presented and also a relationship between the cost and the geometric parameters of the SSLFR. The primary costs considered include material, labor, and tooling costs. A numerical example shows the suitability of the proposed approach.

Mirror rearrangement optimization for uniform flux distribution on the cavity receiver of solar parabolic dish concentrator system

The nonuniform and high-gradient solar radiation flux on the absorber surface of solar dish concentrator/cavity receiver (SDCR) system will affect its operational reliability and service lifetime. Therefore, homogenization of the flux distribution is critical and important. In this paper, 2 mirror rearrangement strategies and its optimization method by combining a novel ray tracing method and the genetic algorithm are proposed to optimize the parabolic dish concentrator (PDC) so as to realize the uniform flux distribution on the absorber surface inside the cavity receiver of SDCR system. The mirror rearrangement strategy includes a mirror rotation strategy and mirror translation strategy, which rotate and translate (along the focal axis) each mirror unit of the PDC to achieve multipoint aiming, respectively. Firstly, a correlation model between the focus spot radius and mirror rearrangement parameters is derived as constraint model to optimize the PDC. Secondly, a novel method named motion accumulation ray-tracing method is proposed to reduce the optical simulation time. The optical model by motion accumulation ray-tracing method and optimization model of SDCR system are established in detailed, and then, an optimization program by combining a ray-tracing code and genetic algorithm code in C++ is developed and verified. Finally, 3 typical cavity receivers, namely, cylindrical, conical, and spherical, are taken as examples to fully verify the effectiveness of these proposed methods. The results show that the optimized PDC by mirror rearrangement strategies can not only greatly improve the flux uniformity (ie, reduce the nonuniformity factor) and reduce the peak local concentration ratio of the absorber surface but also obtain excellent optical efficiency and direct useful energy ratio. A better optimization results when the PDC is optimized by mirror rotation strategy at aperture radius of 7.0 m, focal length of 6.00 m, and ring number of 6; the nonuniform factor of the cylindrical, conical, and spherical cavity receivers is greatly reduced from 0.63, 0.67, and 0.45 to 0.18, 0.17, and 0.26, respectively; the peak local concentration ratio is reduced from 1140.00, 1399.00, and 633.30 to 709.10, 794.00, and 505.90, respectively; and the optical efficiency of SDCR system is as high as 92.01%, 92.13%, and 92.71%, respectively. These results also show that the dish concentrator with same focal length can match different cavity receivers by mirror rearrangement and it can obtain excellent flux uniformity.

Intracavity deformable mirror for beam quality improvement and power enhancement of a passively Q-switched laser.

The performance of the passively Q-switched (PQS) laser deteriorates under high pumping power for the intracavity thermally induced wavefront distortion (thermal distortion for short). A new intracavity deformable mirror (DM) is proposed to compensate the thermal distortion of a PQS laser in this paper. The thermal distortion of the PQS laser is measured using the active deflectometry method. A simulation model is built to investigate the influences of the DM structure parameters on the surface shape of the DM (DMSS). Simulation results indicate that the DMSS matches well with the measured thermal distortion in the PQS laser at the given pumping current. Based on the simulation results, a low-cost, compact intracavity DM consisting of a mirror unit, a heater unit, a cooler unit and a base unit is built and used in the PQS laser. The DMSS is measured by a Zygo interferometer and coincides with the simulation result. In the improved PQS laser experiment, the optimum heater temperatures for the maximum output power and minimum M2 at different pumping currents are measured and given. The output stability of the PQS laser with the DM is tested. By adjusting the heater temperature, the PQS laser could achieve optimum performance in different environmental temperatures with good temperature adaptability. Experiment results verify that the PQS laser with the designed DM could achieve high output power and good beam quality at high pumping currents, as the DM prominently compensates the thermal distortion in the laser.

Wideband and low RCS planar circularly polarized array based on polarization conversion of metasurface

AbstractIn this article, a planar wideband circularly polarized (CP) slot antenna array based on metasurface (MS) with low radar cross section (RCS) is proposed. The array is comprised of CP MS‐based antennas fed with a sequentially rotated feeding network. For each CP antenna, the CP radiation is achieved due to polarization conversion of the MS. Simultaneously, the total MS patches of the array can be viewed as checkerboard composed of MS array and mirror array. A phase difference between the MS units and the mirror units ensures RCS reduction. Simulated results demonstrate that about 34.6% operating bandwidth in the frequency of 4.3–6.1 GHz (both S11 –10 dB and AR &lt; 3 dB). In addition, over 5 dB RCS reduction is obtained in the entire operation band under normal incidence with respect to the array without MS for both x‐ and y‐polarizations. The simulated monostatic RCS less than −30.9 dBsm is observed at 5.0 GHz. A prototype of the array is fabricated and measured, which are in good agreement with simulated results.

Broadband radar cross-section reduction using polarization conversion metasurface

AbstractA wideband and high-efficiency polarization conversion metasurface (PCM) is proposed and applied to reduce radar cross section (RCS). The proposed PCM unit is composed of two oblique asymmetry triangle split rings, which generate multiple plasmon resonances. Simulated and measured results demonstrate that it achieves polarization conversion over 90% from 9.24 to 17.64 GHz. Besides square checkerboard, the proposed PCM units and mirror units are arranged in triangle checkerboard. The mechanisms of both checkerboard PCMs are analyzed based on standard array theory, including the relationship between RCS reduction value and polarization conversion ratio value. The derived formulas provide a guideline to design checkerboard structure based on PCM. Simulated results demonstrate that both checkerboard PCMs achieve over 62% relative bandwidth of 10 dB RCS reduction under normal incidence with respect to the equal-sized metallic plate, which also means that the triangle one could be an alternative solution to reduce RCS. To verify the analyzed and simulated results, the fabricated sample and measured results of both checkerboard PCMs are presented. Good agreements are achieved between measurements, simulations and numerical analysis.

Back-support large laser mirror unit: mounting modeling and analysis

In high-power laser system, the surface wavefront of large optics has a close link with its structure design and mounting method. The back-support transport mirror design is presently being investigated as a means in China’s high-power laser system to hold the optical component firmly while minimizing the distortion of its reflecting surface. We have proposed a comprehensive analytical framework integrated numerical modeling and precise metrology for the mirror’s mounting performance evaluation while treating the surface distortion as a key decision variable. The combination of numerical simulation and field tests demonstrates that the comprehensive analytical framework provides a detailed and accurate approach to evaluate the performance of the transport mirror. It is also verified that the back-support transport mirror is effectively compatible with state-of-the-art optical quality specifications. This study will pave the way for future research to solidify the design of back-support large laser optics in China’s next generation inertial confinement fusion facility.

Close-loop performance of a high precision deflectometry controlled deformable mirror (DCDM) unit for wavefront correction in adaptive optics system

We present a high precision deflectometry system (DS) controlled deformable mirror (DM) solution for optical system. Different from wavefront and non-wavefront system, the DS and the DM are set to be an individual integrated DCDM unit and can be installed in one base plate. In the DCDM unit, the DS can directly provide the influence functions and surface shape of the DM to the industrial computer in any adaptive optics system. As an integrated adaptive unit, the DCDM unit could be put into various optical systems to realize aberration compensation. In this paper, the configuration and principle of the DCDM unit is introduced first. Theoretical simulation on the close-loop performance of the DCDM unit is carried out. Finally, a verification experiment is proposed to verify the compensation capability of the DCDM unit.

Wideband RCS Reduction Using Polarization Conversion Metasurface and Partially Reflecting Surface

A high-gain antenna with wideband low radar cross-section (RCS) property using polarization conversion metasurface (PCM) and partially reflecting surface (PRS) is investigated. PCM and PRS are printed on two sides of a substrate, above the microstrip patch antenna to form Fabry–Perot (F-P) resonant cavity. Due to the symmetrical arrangement of PCM unit and its mirror unit, remarkable wideband radar cross-section reduction (RCSR) is obtained in both x - and y -polarizations. Simulated and measured results show that combination of PCM with PRS antenna contributes to significant in-band and out-of-band RCSR, as well as 7 dB gain enhancement. Wideband RCSR ranging from 9 to 20 GHz with maximum in -band value is 20 dB at 9.4 GHz, and 33 dB out of band verified its superiority in RCS control.

太阳能聚光器镜面单元的支撑-调节结构和位姿校准

太阳能聚光器镜面单元的支撑-调节结构和位姿校准

Geometry and spatial orientation of a quadruple node of triple junctions in a europium-doped KI crystal as determined by epifluorescence microscopy.

The geometry and spatial orientation of a typical arrangement of four triple junctions and six grain boundaries sharing a common quadruple node in a Eu2+ -doped KI crystal are investigated by epifluorescence microscopy using the proper doping ion as a fluorochrome. To achieve this, an electronic three-dimensional reconstruction of the studied arrangement of crystal defects was built from microscopy images of different optical cross-sections of this arrangement. Previously, the doping ions were induced, by subjecting the crystal to a long annealing treatment, to form europium precipitates into the crystal grain boundaries. The optical properties of these precipitates were characterized by fluorescence spectrophotometry and used to tailor properly the microscope fluorescence mirror unit, whereas the single-crystal character of the microscope samples was tested by X-ray diffraction. By inspecting the reconstruction under handling, the dihedral angles between the grain boundaries that meet at a common triple junction as well as the angles between the triple junctions sharing the quadruple node were successfully measured at the quadruple node site. The measuring procedures are carefully described. The resulting values (132º, 109º, 119º, 125º, 111º, 124º, 124º, 111º, 125º, 129º, 109º and 122º ± 2º) for the dihedral angles depart for some few degrees from the characteristic angle (120º) of a 3-fold symmetry rotation, whereas the resulting values (104º, 111º, 117º, 103º, 100º and 121º ± 2º) for the triple junction angles are not far from the characteristic angle (109.47º) between the legs of a tetrahedron. These results, indicating that in the close neighbourhood of the quadruple node the studied arrangement of crystal defects deviates from a state of full structural stability, allow this arrangement to be fairly modelled in such a neighbourhood by a distorted tetrahedron. The angles between the studied triple junctions and the host lattice directions [11¯1], [111¯], [1¯11] and [1¯1¯1¯] were also measured at the quadruple node site, and the resulting values (8º, 7º, 6º and 8º ± 2º, respectively) indicate that a symmetry mismatching exists between the tetrahedral model of the studied Eu2+ -decorated arrangement of crystal defects and the KI matrix cubic crystal lattice. This symmetry mismatching is discussed to be responsible for the observed deviation from structural stability.