Showing papers on "Collimated light published in 2014"

Devices and methods for a rotating LIDAR platform with a shared transmit/receive path

Abstract: A LIDAR device may transmit light pulses originating from one or more light sources and may receive reflected light pulses that are then detected by one or more detectors. The LIDAR device may include a lens that both (i) collimates the light from the one or more light sources to provide collimated light for transmission into an environment of the LIDAR device and (ii) focuses the reflected light onto the one or more detectors. The lens may define a curved focal surface in a transmit path of the light from the one or more light sources and a curved focal surface in a receive path of the one or more detectors. The one or more light sources may be arranged along the curved focal surface in the transmit path. The one or more detectors may be arranged along the curved focal surface in the receive path.

3D depth point cloud from timing flight of 2D scanned light beam pulses

Abstract: A light detection and ranging (LIDAR) system has an emitter which produces a sequence of outgoing pulses of coherent collimated light that transmitted in a given direction, a mirror system having a scanning mirror that is positioned to deflect the outgoing pulse sequence towards a scene, and a detector collocated with the emitter and aimed to detect a sequence of incoming pulses being reflections of the outgoing pulses that are returning from said given direction and have been deflected by the scanning mirror. An electronic controller communicates with the emitter and the detector and controls the scanning mirror, so that the outgoing pulses scan the scene and the controller computes a radial distance or depth for each pair of outgoing and incoming pulses and uses the computed radial distance to provide a scanned 3D depth map of objects in the scene. Other embodiments are also described.

Compact Projection Light Engine For A Diffractive Waveguide Display

Abstract: The technology provides a waveguide display having a compact projection light engine and a diffractive waveguide. The diffractive waveguide includes input diffraction gratings with rolled k-vectors. The projection light engine provides collimating light to a projected exit pupil external to the diffractive waveguide. The projection light engine components may include a light (or illuminating) source, microdisplay, lenticular screen, doublet, polarizing beam splitter (PBS), clean-up polarizer, fold mirror, curved reflector and quarter waveplate. A method of manufacturing a diffractive waveguide includes providing input gratings with rolled k-vectors. Rays of light are diffracted by, and passed through, a master hologram to form input diffraction gratings of a copy substrate. A second copy substrate may likewise be formed with a different master hologram. Multiple copy substrates may be assembled to form a multi-layer diffractive waveguide (or multiple diffractive waveguides) having input diffraction gratings with increased diffraction efficiency and angular bandwidth.

Bit error rate of focused Gaussian beams in weak oceanic turbulence

Abstract: Formulation of the on-axis scintillation index of a focused Gaussian beam in weak oceanic turbulence is derived by using the Rytov method, and using this formulation, the average bit error rate (BER) is evaluated. The scintillation indices of collimated, focused Gaussian, plane, and spherical beams are compared. The scintillation index and BER versus the average signal-to-noise ratio is found by using the log-normal distributed intensity for the collimated and focused Gaussian beams, which are exhibited for various source sizes α(s), focal lengths F(s), rates of dissipation of the mean squared temperature χ(T), and rates of dissipation of the turbulent kinetic energy per unit mass of fluid e. Focused beams are found to have important advantages over collimated beams. For the focused beam, as the source size increases, the scintillation index and BER decrease. When the focal length is equal to the propagation length, the BER is found to possess the smallest value. The BER is proportional to χ(T), but inversely proportional to e.

Projection optical system for coupling image light to a near-eye display

Abstract: Technology is described for a projection optical system which optically couples image light from an image source to a near-eye display (NED) of a wearable near-eye display device The projection optical system and the image source make up a projection light engine Light from the image source is directed to a birdbath reflective optical element which is immersed in high index glass The image light is reflected and collimated by the birdbath element and travels outside a housing of the projection light engine forming an external exit pupil, meaning the exit pupil is external to the projection light engine A waveguide optically couples the image light of the external exit pupil An example of a waveguide which can be used is a surface relief grating waveguide

Computational spectrometer based on a broadband diffractive optic.

Abstract: We describe a simple, compact, low-cost spectrometer comprised of a broadband diffractive optic and a sensor array. The diffractive optic is designed to disperse incident collimated light onto the sensor array in a prescribed manner defined by its spatial-spectral point-spread function. By applying a novel nonlinear optimization method, we show that it is possible to reconstruct the unknown spectrum from the measured image on the sensor array. We experimentally reconstructed numerous spectra with resolution as small as ~1nm and bandwidths as large as 450nm. Furthermore, we readily resolved two spatially overlapping but spectrally distinct objects. The spectral resolution is determined by dispersion of the diffractive optic via a spectral correlation function, while the bandwidth is limited primarily by the quantum efficiency of the sensor array. Using simulations, we present a spectral extraction of solar radiation from 300nm to 2500nm with a resolution of ~0.11nm. Moreover, our technique utilizes almost all the incident photons owing to the high transmission efficiency of the broadband diffractive optic, which allows for fast spectroscopy with dim illumination. Due to its simple construction with no moving parts, our technique could have important applications in portable, low-cost spectroscopy.

Real-time proton beam range monitoring by means of prompt-gamma detection with a collimated camera

Abstract: Prompt-gamma profile was measured at WPE-Essen using 160 MeV protons impinging a movable PMMA target. A single collimated detector was used with time-of-flight (TOF) to reduce the background due to neutrons. The target entrance rise and the Bragg peak falloff retrieval precision was determined as a function of incident proton number by a fitting procedure using independent data sets. Assuming improved sensitivity of this camera design by using a greater number of detectors, retrieval precisions of 1 to 2 mm (rms) are expected for a clinical pencil beam. TOF improves the contrast-to-noise ratio and the performance of the method significantly.

Collimated blue and infrared beams generated by two-photon excitation in Rb vapor

Abstract: Utilizing two-photon excitation in hot Rb vapor we demonstrate the generation of collimated optical fields at 420 and 1324 nm. Input laser beams at 780 and 776 nm enter a heated Rb vapor cell collinear and circularly polarized, driving Rb atoms to the 5D5/2 state. Under phase-matching conditions coherence among the 5S1/2→5P3/2→5D5/2→6P3/2 transitions produces a blue (420 nm) beam by four-wave mixing. We also observe a forward and backward propagating IR (1324 nm) beam, due to cascading decays through the 6S1/2→5P1/2 states. Power saturation of the generated beams is investigated by scaling the input powers to greater than 200 mW, resulting in a coherent blue beam of 9.1 mW power, almost an order of magnitude larger than previously achieved. We measure the dependences of both beams in relation to the Rb density, the frequency detuning between Rb ground-state hyperfine levels, and the input laser intensities.

Time-sequential autostereoscopic 3-D display with a novel directional backlight system based on volume-holographic optical elements

Abstract: A novel directional backlight system based on volume-holographic optical elements (VHOEs) is demonstrated for time-sequential autostereoscopic three-dimensional (3-D) flat-panel displays. Here, VHOEs are employed to control the direction of light for a time-multiplexed display for each of the left and the right view. Those VHOEs are fabricated by recording interference patterns between collimated reference beams and diverging object beams for each of the left and right eyes on the volume holographic recording material. For this, self-developing photopolymer films (Bayfol® HX) were used, since those simplify the manufacturing process of VHOEs substantially. Here, the directional lights are similar to the collimated reference beams that were used to record the VHOEs and create two diffracted beams similar to the object beams used for recording the VHOEs. Then, those diffracted beams read the left and right images alternately shown on the LCD panel and form two converging viewing zones in front of the user’s eyes. By this he can perceive the 3-D image. Theoretical predictions and experimental results are presented and the performance of the developed prototype is shown.

Gate-controlled mid-infrared light bending with aperiodic graphene nanoribbons array

Abstract: Graphene plasmonic nanostructures enable subwavelength confinement of electromagnetic energy from the mid-infrared down to the terahertz frequencies By exploiting the spectrally varying light scattering phase at vicinity of the resonant frequency of the plasmonic nanostructure, it is possible to control the angle of reflection of an incoming light beam We demonstrate, through full-wave electromagnetic simulations based on Maxwell equations, the electrical control of the angle of reflection of a mid-infrared light beam by using an aperiodic array of graphene nanoribbons, whose widths are engineered to produce a spatially varying reflection phase profile that allows for the construction of a far-field collimated beam towards a predefined direction

Concurrence of monoenergetic electron beams and bright X-rays from an evolving laser-plasma bubble

Abstract: Desktop laser plasma acceleration has proven to be able to generate gigaelectronvolt-level quasi-monoenergetic electron beams. Moreover, such electron beams can oscillate transversely (wiggling motion) in the laser-produced plasma bubble/channel and emit collimated ultrashort X-ray flashes known as betatron radiation with photon energy ranging from kiloelectronvolts to megaelectronvolts. This implies that usually one cannot obtain bright betatron X-rays and high-quality electron beams with low emittance and small energy spread simultaneously in the same accelerating wave bucket. Here, we report the first (to our knowledge) experimental observation of two distinct electron bunches in a single laser shot, one featured with quasi-monoenergetic spectrum and another with continuous spectrum along with large emittance. The latter is able to generate high-flux betatron X-rays. Such is observed only when the laser self-guiding is extended over 4 mm at a fixed plasma density (4 × 1018 cm−3). Numerical simulation reveals that two bunches of electrons are injected at different stages due to the bubble evolution. The first bunch is injected at the beginning to form a stable quasi-monoenergetic electron beam, whereas the second one is injected later due to the oscillation of the bubble size as a result of the change of the laser spot size during the propagation. Due to the inherent temporal synchronization, this unique electron–photon source can be ideal for pump–probe applications with femtosecond time resolution.

An orbital angular momentum radio communication system optimized by intensity controlled masks effectively: Theoretical design and experimental verification

Abstract: A system of generating and receiving orbital angular momentum (OAM) radio beams, which are collectively formed by two circular array antennas (CAAs) and effectively optimized by two intensity controlled masks, is proposed and experimentally investigated. The scheme is effective in blocking of the unwanted OAM modes and enhancing the power of received radio signals, which results in the capacity gain of system and extended transmission distance of the OAM radio beams. The operation principle of the intensity controlled masks, which can be regarded as both collimator and filter, is feasible and simple to realize. Numerical simulations of intensity and phase distributions at each key cross-sectional plane of the radio beams demonstrate the collimated results. The experimental results match well with the theoretical analysis and the receive distance of the OAM radio beam at radio frequency (RF) 20 GHz is extended up to 200 times of the wavelength of the RF signals, the measured distance is 5 times of the original measured distance. The presented proof-of-concept experiment demonstrates the feasibility of the system.

Numerical simulation of x-ray luminescence optical tomography for small-animal imaging

Abstract: X-ray luminescence optical tomography (XLOT) is an emerging hybrid imaging modality in which x-ray excitable particles (phosphor particles) emit optical photons when stimulated with a collimated x-ray beam. XLOT can potentially combine the high sensitivity of optical imaging with the high spatial resolution of x-ray imaging. For reconstruction of XLOT data, we compared two reconstruction algorithms, conventional filtered backprojection (FBP) and a new algorithm, x-ray luminescence optical tomography with excitation priors (XLOT-EP), in which photon propagation is modeled with the diffusion equation and the x-ray beam positions are used as reconstruction priors. Numerical simulations based on dose calculations were used to validate the proposed XLOT imaging system and the reconstruction algorithms. Simulation results showed nanoparticle concentrations reconstructed with XLOT-EP are much less dependent on scan depth than those obtained with FBP. Measurements at just two orthogonal projections are sufficient for XLOT-EP to reconstruct an XLOT image for simple source distributions. The heterogeneity of x-ray energy deposition is included in the XLOT-EP reconstruction and improves the reconstruction accuracy, suggesting that there is a need to calculate the x-ray energy distribution for experimental XLOT imaging.

LED high-beam headlamp based on free-form microlenses.

Abstract: To eliminate the rainbow phenomenon of white LED sources caused by optical dispersion in a motorcar's headlamp with a thick lens, we propose an LED high-beam headlamp based on free-form microlenses. The free-form microlenses include total reflection surfaces, which collimate the beams emitting from the LED source, and microlens structures, which redistribute the collimated beams to the target plane. We optimize the map relationship between the LED source and the illumination plane according to ECE regulation R112. Simulation and experiment results show that our proposed free-form microlenses could efficiently distribute light radiated from the LED source. All illumination on the test points and zones could reach ECE regulation R112. There is little dispersion in the light pattern in the target plane.

In-beam PET imaging for on-line adaptive proton therapy: an initial phantom study.

Abstract: We developed and investigated a positron emission tomography (PET) system for use with on-line (both in-beam and intra-fraction) image-guided adaptive proton therapy applications. The PET has dual rotating depth-of-interaction measurable detector panels by using solid-state photomultiplier (SSPM) arrays and LYSO scintillators. It has a 44 mm diameter trans-axial and 30 mm axial field-of-view (FOV). A 38 mm diameter polymethyl methacrylate phantom was placed inside the FOV. Both PET and phantom axes were aligned with a collimated 179.2 MeV beam. Each beam delivered ∼50 spills (0.5 s spill and 1.5 s inter-spill time, 3.8 Gy at Bragg peak). Data from each beam were acquired with detectors at a given angle. Nine datasets for nine beams with detectors at nine different angles over 180° were acquired for full-tomographic imaging. Each dataset included data both during and 5 min after irradiations. The positron activity-range was measured from the PET image reconstructed from all nine datasets and compared to the results from simulated images. A 22Na disc-source was also imaged after each beam to monitor the PET system's performance. PET performed well except for slight shifts of energy photo-peak positions (<1%) after each beam, due mainly to the neutron exposure of SSPM that increased the dark-count noise. This minor effect was corrected offline with a shifting 350–650 keV energy window for each dataset. The results show a fast converging of activity-ranges measured by the prototype PET with high sensitivity and uniform resolution. Sub-mm activity-ranges were achieved with minimal 6 s acquisition time and three spill irradiations. These results indicate the feasibility of PET for intra-fraction beam-range verification. Further studies are needed to develop and apply a novel clinical PET system for on-line image-guided adaptive proton therapy.

Magnetic collimation of relativistic positrons and electrons from high intensity laser-matter interactions

Abstract: Collimation of positrons produced by laser-solid interactions has been observed using an externally applied axial magnetic field. The collimation leads to a narrow divergence positron beam, with an equivalent full width at half maximum beam divergence angle of 4° vs the un-collimated divergence of about 20°. A fraction of the laser-produced relativistic electrons with energies close to those of the positrons is collimated, so the charge imbalance ratio (ne−/ne+) in the co-propagating collimated electron-positron jet is reduced from ∼100 (no collimation) to ∼2.5 (with collimation). The positron density in the collimated beam increased from 5 × 107 cm−3 to 1.9 × 109 cm−3, measured at the 0.6 m from the source. This is a significant step towards the grand challenge of making a charge neutral electron-positron pair plasma jet in the laboratory.

Light extraction enhancement with radiation pattern shaping of LEDs by waveguiding nanorods with impedance-matching tips

Abstract: Syringe-like ZnO nanorods (NRs) were fabricated on InGaN/GaN light emitting diodes (LEDs) by a hydrothermal method. Without sacrificing the electrical performances of LEDs, syringe-like NRs can enhance light extraction capability by 10.5% at 20 mA and shape the radiation profile with a view angle collimated from 136° to 121°. By performing optical experiments and simulation, it is found that the superior light extraction efficiency with a more collimated radiation pattern is attributed to the waveguiding effect of NRs and the mitigation of abrupt index change by the tapered ends of syringe-like ZnO NRs. This work demonstrates the importance of the nanostructure morphology in LED performances and provides the architecture design guidelines of nanostructures to a variety of optical devices.

Methods and Means for Creating Three-Dimensional Borehole Image Data

Abstract: A method of creating three-dimensional borehole data is provided, including illuminating a borehole using collimated beams of electromagnetic radiation; rotating the collimated beams in a sweep of at least 360 degrees; detecting backscattered electromagnetic radiation returned from surfaces of associated illumination planes using electromagnetic radiation sensors; converting detected radiation into a corresponding set of volume image data; analyzing the volume image data using computational visualization processing techniques; and creating a three-dimensional image representative of the volume data. Imaging methodologies include a complete, radial conic-shaped surface while the imaging system remains stationary; a plurality of scans performed while longitudinally moving the imaging system a distance d through the borehole between image capture operations; and a plurality of scans performed while longitudinally moving the imaging system a distance d, where d is a distance less than or equal to the collimated beam thickness, so that adjacent scans partially overlap.

Methods and apparatus for determining particle characteristics

Abstract: Apparatus and methods are described for determining information about at least one particle by measuring light scattered from the particles. Scattered light is detected from a region of a particle dispersion or from a larger region in a generally collimated illumination beam. Scattered light is also detected from a plurality of regions for improvement of repeatability.

An XUV optics beamline at BESSY II

Abstract: The design for a new XUV-Optics Beamline is presented. The collimated plane grating monochromator (PGM-) beamline at a bending magnet is setup at the BESSY-II synchrotron radiation facility within the framework of the blazed-grating production facility. Coupled to a versatile four-circle (ten ax es) UHV- reflectometer as a permanent end station the whole setup is dedicated to at-wavelength characterizati on and calibration of the in-house produced precision gratings and novel nano-optical devices as well as mirrors, multila yered systems etc. It is also open to exte rnal projects employing reflectometry, spectroscopy or scattering techniques. According to its purpose, this beamline has specific features, such as: very high spectral purity, provided by two independent high order suppression systems, an advanced aperture system for suppression of stray light and scattered radiation, a broad energy range between 10 eV and 2000 eV, small beam divergence and spot size on the sample. Thus this Optics Beamline will become a powerful metrology tool for reflectivity measurements in s- or p-polarisation geometry with linearly or elliptically polarized light on real optics up to 360 mm length and 4 kg weight. Keywords: At-wavelength metrology, UV, EUV, VUV, XUV, reflection gratings, reflectometry, polarimetry, synchrotron instrumentation

Reduced-phase dual-illumination interferometer for measuring large stepped objects.

Abstract: We present a reduced-phase dual-illumination interferometer (RPDII) that measures the topography of a sample with large step height variation. We experimentally demonstrate the basic principle and the feasibility of this novel single-shot quantitative phase imaging. Two beams of this interferometer illuminate a sample at different incident angles, and two phases of the different incident angles and their phase difference are simultaneously recorded using three spatial frequencies. The relative phase difference between two beams of an RPDII can be controlled by adjusting the angle such that the maximum phase difference is smaller than 2π, and thus there is no phase wrapping ambiguity in the reconstructed phase. One 4f optical system with a transmission grating is used to illuminate the sample with two collimated beams incident at different angles. The feasibility of this technique is demonstrated by measuring the thicknesses of two stepped metal layers with heights of 150 and 660 μm. Although the change in stepped height is more than 1000 times the wavelength of the laser used in our interferometer, the thicknesses of these two metal layers are successfully obtained without the use of an unwrapping algorithm.

How well do we know the polar hydrogen distribution on the Moon

Abstract: A detailed comparison is made of results from the Lunar Prospector Neutron Spectrometer (LPNS) and the Lunar Exploration Neutron Detector Collimated Sensors for Epithermal Neutrons (LEND CSETN). Using the autocorrelation function and power spectrum of the polar count rate maps produced by these experiments, it is shown that the LEND CSETN has a footprint that is at least as big as would be expected for an omnidirectional detector at an orbital altitude of 50 km. The collimated flux into the field of view of the collimator is negligible. A dip in the count rate in Shoemaker crater is found to be consistent with being a statistical fluctuation superimposed on a significant, larger-scale decrease in the count rate, providing no evidence for high spatial resolution of the LEND CSETN. The maps of lunar polar hydrogen with the highest contrast, i.e., spatial resolution, are those resulting from pixon image reconstructions of the LPNS data. These typically provide weight percentages of water-equivalent hydrogen that are accurate to 30% within the polar craters.

Perspective display device

Abstract: The invention discloses a perspective display device based on wedge-shaped plane expanding optical waveguide. The perspective display device comprises a display light source, a column-shaped lens, a plane waveguide substrate, a wedge-shaped substrate and a light wave beam expanding set in sequence. The display light source is used for emitting image light waves needed for displaying. The column-shaped lens carries out collimation on the image light waves and outputs collimation light waves. The plane waveguide substrate is aligned with the light waves for reflecting transmission to form total reflection light waves. The wedge-shaped substrate forms a wedge-shaped light wave coupling output lens and carries out coupling on the total reflection light waves and then outputs coupling light waves. The light wave beam expanding set carries out plane expanding on the coupling light waves which are output as light signals capable of being identified, and accordingly images are transmitted into the view field range of a user. The whole perspective display device has the advantages of being compact in structure, small in size, light in weight and simple in manufacturing technology, a large view field is achieved, and the perspective display device has the obvious advantages that the output images are clear, the high resolution ratio is achieved, image displaying quality is high, and the influence of double images on image definition can be effectively avoided.

Acoustic Mach–Zehnder interferometer utilizing self-collimated beams in a two-dimensional phononic crystal

Abstract: Numerical investigation of a Mach–Zehnder interferometer implemented by steering self-collimated acoustic beams in a two-dimensional phononic crystal is presented. Mirrors of the interferometer are optimized by modifying the radii of the steel cylinders in water so that the working frequencies lie in a band gap. The beam splitters optimized in a similar manner ensure equal splitting of the beams. In the all-water case of host liquid, the interferometer operates unidirectionally such that transmission through only one of the two output terminals is achieved. Corresponding transmittances are 85.9% and 6.0% for the transmitting and blocked terminals, respectively. The device can be utilized in sensing variations in the weight fraction of ethanol in water in a cell on the path of one of the two split beams. Phase difference accumulated in the sample cell varies linearly with ethanol weight fraction up to 15%. Contrast ratio of the calculated transmittances can be used as a measure of ethanol content in water, as it varies as a cosine function of ethanol weight fraction.

Measurement of bow tie profiles in CT scanners using a real‐time dosimeter

Abstract: Purpose: Several areas of computed tomography (CT) research require knowledge about the intensity profile of the x-ray fan beam that is introduced by a bow tie filter. This information is considered proprietary by CT manufacturers, so noninvasive measurement methods are required. One method using real-time dosimeters has been proposed in the literature. A commercially available dosimeter was used to apply that method, and analysis techniques were developed to extract fan beam profiles from measurements. Methods: A real-time ion chamber was placed near the periphery of an empty CT gantry and the dose rate versus time waveform was recorded as the x-ray source rotated about the isocenter. In contrast to previously proposed analysis methods that assumed a pointlike detector, the finite-size ion chamber received varying amounts of coverage by the collimated x-ray beam during rotation, precluding a simple relationship between the source intensity as a function of fan beam angle and measured intensity. A two-parameter model for measurement intensity was developed that included both effective collimation width and source-to-detector distance, which then was iteratively solved to minimize the error between duplicate measurements at corresponding fan beam angles, allowing determination of the fan beam profile from measured dose-rate waveforms. Measurements were performed on five different scanner systems while varying parameters such as collimation, kVp, and bow tie filters. On one system, direct measurements of the bow tie profile were collected for comparison with the real-time dosimeter technique. Results: The data analysis method for a finite-size detector was found to produce a fan beam profile estimate with a relative error between duplicate measurement intensities of <5%. It was robust over a wide range of collimation widths (e.g., 1–40 mm), producing fan beam profiles that agreed with a relative error of 1%–5%. Comparison with a direct measurement technique on one system produced agreement with a relative error of 2%–6%. Fan beam profiles were found to differ for different filter types on a given system and between different vendors. Conclusions: A commercially available real-time dosimeter probe was found to be a convenient and accurate instrument for measuring fan beam profiles. An analysis method was developed that could handle a wide range of collimation widths by explicitly considering the finite width of the ion chamber. Relative errors in the profiles were found to be less than 5%. Measurements of five different clinical scanners demonstrate the variation in bow tie designs, indicating that generic bow tie models will not be adequate for CT system research.

Dual spectral-band interferometry for spatio-temporal characterization of high-power femtosecond lasers

Abstract: We present and demonstrate a technique called RED-SEA TADPOLE for the spatio-temporal characterization of high peak power femtosecond lasers. It retains the basic principle of an existing method, where a scanning monomode fiber is utilized in an interferometric scheme to measure the spectral amplitude and phase at all points across an ultrashort laser beam. We combine this approach with dual spectral-band interferometry, to correct for all phase errors occurring in this interferometer, thus allowing for the simultaneous measurement of the beam wavefront and pulse front in a collimated beam of large diameter. The generic phase correction procedure implemented here can also be extended to other fiber optic device applications sensitive to phase fluctuations.

Collimating light guide plate, diffusing unit, and display apparatus employing the same

Abstract: A diffusing unit includes: a polarizing plate; and a diffusing layer integrally provided on a surface of the polarizing plate without an air layer therebetween. By using a display apparatus employing a collimating light guide plate and the diffusing unit, the optical performances such as resolution and viewing angle can be improved. Also, because gray scale inversion and color shifts can be reduced or eliminated using collimated light, image quality of the display apparatus can be improved.

Method for controlling array light beam co-target collimation of target in loop based on light spot centroid calculation

Abstract: The invention relates to a method for controlling array light beam co-target collimation of a target in a loop based on light spot centroid calculation. The coordinates of the centroid of a light spot on an imaging plane are obtained through a light spot centroid algorithm, a tilt control quantity which needs to be conducted on each light beam is obtained according to the quantitative relation between tilt control of a tilting mirror of the corresponding light beam and a light spot movement vector, and the centroid of the light spot is moved to a target spot of an image device through control over the tilting mirrors. Co-target collimation of all the light beams of the target in the loop is realized through sequential control cover the array light beams. There is no need to accurately describe or obtain a light path, and a control scheme is simple and convenient and easy to implement. The adopted centroid of the light spot serves as a performance evaluation function which is simple, convenient, high in real-time performance, and remarkable in effect, and consumes a short time. The method for controlling array light beam co-target collimation of the target in the loop based on light spot centroid calculation has extensive application prospects in satellite tracking, the directed energy technology and other fields.