We report a framing imaging based on noncollinear optical parametric amplification (NCOPA), named FINCOPA, which applies NCOPA for the first time to single-shot ultrafast optical imaging. In an experiment targeting a laser-induced air plasma grating, FINCOPA achieved 50 fs-resolved optical imaging with a spatial resolution of ∼83 lp / mm and an effective frame rate of 10 trillion frames per second (Tfps). It has also successfully visualized an ultrafast rotating optical field with an effective frame rate of 15 Tfps. FINCOPA has simultaneously a femtosecond-level temporal resolution and frame interval and a micrometer-level spatial resolution. Combining outstanding spatial and temporal resolutions with an ultrahigh frame rate, FINCOPA will contribute to high-spatiotemporal resolution observations of ultrafast transient events, such as atomic or molecular dynamics in photonic materials, plasma physics, and laser inertial-confinement fusion.
A high-speed digital holography based on a liquid crystal Spatial Light Modulator (LC-SLM) is presented. The
production of multi-beam and control of their delay time can be achieved by controllable wavefront coding theory. In this
paper, a Dammann phase grating was designed using a SLM to product multi-beam for extremely high speed digital
holographic imaging. The required beam deflection could be obtained by adjusting programmable phase mask for
controlling the spatial diffraction of input beam. The framing time is decided by interval beam angles and the distances
between input plane and record plane. Theoretical derivate of generation multi beams based on SLM was proposed, and
phase recover software was also made.
We demonstrated a single-shot quasi-on-axis digital holography which is capable of simultaneously capturing two-step phase-shifting interferences. A dual-channel interferometer was employed to monitor the Gouy phase-shifting between two orthogonal polarized references which was introduced by two confocal lenses. A new algorithm was derived for reconstruction the complex field of the object’s wavefront according to the feature of Gouy phase-shifting. Simulation was carried out and recover software was also made. The proposed approach can also be applied to single-shot quasi-onaxis digital holography for real time measurement.
Eliminating the sign ambiguity is one of the important steps in phase extraction from a single interferogram. We propose a new method based on energy minimization to remove the sign ambiguity when retrieving a phase. Markov random field (MRF) is used to build up the pairwise relationship of a sign map. The method is thus a compromise between “global” and “local” methods. To alleviate the disturbance of noise, we employ additionally a neighborhood-direction-averaging and an adaptive filter instead of using optical flow. The gradient orientation is properly smoothed for MRF observation. Various techniques for minimizing MRF energy are compared and simulation results demonstrate the effectiveness of our method.
KEYWORDS: Digital holography, Holograms, High speed photography, Charge-coupled devices, Fourier transforms, Holography, Digital recording, 3D image reconstruction, Optical filters, Diffraction
In this paper, the characteristics of Fraunhofer digital holography are investigated. With Fraunhofer digital holography,
we could simplify the calculational and reconstructed process. Moreover, the spectrum of the hologram did not contain
the original images and the limitation of recording frame caused by the size of objects was reduced. The number of
recording frame could be increased, especially for the objects of concentrative spectrum. Thus, with Fraunhofer digital
holography, it could not only simplify the process of reconstruction and calculation, but also improve the framing
capability in high-speed photography.
Up to date, there has still been no electronic camera that can match a rotating mirror camera with film for the main
features; therefore, it is necessary to further make R&D work in field of rotating mirror cameras. In this paper, some key
problems for this kind of camera have been discussed in detail, which cover the new information theory, the advanced
techniques of the optical accelerating, the shape and size calculation of rotating mirror surface in any case, the nonberyllium
rotating mirror with the same deformation as beryllium rotating mirror, and the perfect designing theory of
camera obscura.
This contribution focuses on the tubeless imaging, the extreme-high speed imaging. A detail discussion is presented on
how and why to make them, which would be the most important in the high speed imaging field in the future.
Tubeless extreme-high speed imaging can not only be used to observe the transient processes like collision, detonating,
and high voltage discharge, but also to research the processes like disintegration and transfer of phonon and exacton in
solid, photosynthesis primitive reaction, and electron dynamics inside atom shell. Its imaging frequency is about
107~1015fps.
For this kind of imaging, the mechanism of how forming both high speed and framing would better make fine use of the
light speed, the light parallelism, the parameters of light wave such as its amplitude, phase, polarization and wave length,
and even quantum characteristics of photons. In the cascade connection system of electromagnetic wave and particle
wave, it is able to simultaneously realize high level both the temporal resolution and the spatial resolution, and it would
be possible to break through the limit of the Heisenberg uncertainty correlation of the optical frequency band.
In this paper, we proposed a new method, controllable rectangle filter, to improve the resolution of reconstruction in
multi-frame digital holography. In this method, the entire process needs only one hologram with multi-frame digital
holographic interference and the different images' spectrum can be obtained separately without mutual influence.
Therefore the size limiting of the recording objects is reduced and the frame amounts can be increased. Moreover, the
nonessential information of zero-order and the conjugate image can be eliminated well, and the resolution of the
reconstructed images is enhanced. Theoretical analysis and experimental results show that it is a realistic and practical
approach.
This paper analyses a disparity correction of an advanced multi-sparkle camera system. This system is also called
Cranz-Schardin camera, which a method to achieve extreme high-speed photography. The camera axis in this system
have an angle with principal optical axis, so each image taking by different cameras in system is formed by different
orientation projections of the object, and this process generates parallax among the different cameras. In order to solve
this problem, camera calibration method is setting up after a detailed analysis of this system. A planar calibration is used
as standard reference object in experiment. And image corresponding relationship among different cameras can be built
through learning the position changes of feature points in different cameras. Then, grab pictures from transient
phenomenon which need to be analyzed, and after image processing on these pictures with the image corresponding
relationship, the disparity influence on experiment images in this advanced multi-sparkle camera system would be
diminished.
Holography based extreme high-speed photography (EHSP) is a novel technique to study extreme high speed
photography with holography. In order to get multi-frame holograms in high speed holography, studying the framing
principle is very important. Coding reference beam is essential to get multi-frame digital hologram. In this paper,
multi-frame digital holography based on Fourier transformed setup is presented. We study the azimuth encoding method
for the recording theoretically. Point light sources in x-y plane arrange in a narrow circle are selected as reference wave
and the object wave is located in origin of x-y plane. Every point light source stands for a certain azimuth angular. For
the radius of the circle is much smaller than the recording distance, it can be approximately regarded as quasi-on-axis
digital holography. Multiple digital holograms are stored in a single CCD frame, and reconstructed simultaneously. For a
certain magnitude of object, the minimize framing angular, namely, the least angular of two neighboring points, is
carefully studied. And stationary experiment results are also presented. Theoretic and experimental result show that
multi-frame digital holograms with azimuth encoding method can get multiple frames that the EHSP requires. This
indicates that, this encoding method can be used in high speed photography to get multi-frame images.
In order to enlarge the effective field, field correctors were introduced into the R-C system. In this paper, discussed the
relationship among the field corrector, focal ratio of the primary mirror and the vertex back focus. Five sets of correctors
were designed for various Fp of the primary mirror of the RC systems: Fp/1.1, Fp/1.5, Fp/1.8, Fp/2, and Fp/2.5. The
results indicate that the decrease of the focal ratio of the primary increases the difficulty of the field correctors' design.
A simple, flexible and real-time calibration method is proposed to solve the calibrating problems of line structure light sensor such as requirement of high accurate calibration model, complicated calibrating procedure and so on. First, a 2D calibration plane with tessellated pattern is placed at several arbitrary places in the measurement range of sensor, and the pictures of calibration board on these positions are recoded. The parameters of camera are estimated from these pictures. Secondly, the line structure light is turned on, and projected on the surface of calibration board. Several pictures are captured while the board is being moved along the direction of line structure light. Thirdly, the rotating matrixes and transform vectors between the local coordinates of these planes and the global coordinate of sensor are estimated. The global coordinates of the control points falling on the line structure light plane were calculated according to these matrixes and vectors. Finally, the model parameters of the sensor at working state are optimized with these control points. The cost of calibration equipment is greatly reduced and the calibrating procedure is simplified with the proposed approach. So it can promote the engineering applications of the line structure light sensor. It shows that this method is practical for surface measurement. The height error (RMS) of the measured object reaches 0.03mm in the region of 200mm x 150mm.
The methods of numerical analysis for the strength and vibration modals of rotating mirrors were presented based
respectively on the three-dimensional elastic mechanics and dynamics. On strength computation, the finite element
models of rotating mirror were established according to the real structure of mirror, and the rotating three-faced
aluminous and beryllium mirrors were analysed contrastively. Results display that the surface deformation quantity of the
aluminous mirror is approximately 20 times as large as beryllium one, and the maximum stress is 1.6 times against the
latter. Then, the three-faced aluminous mirrors were analyzed at variedly fit between shaft and axle hole. One conclusion
is gotten out that the mirror strength is foreign to fits, but it is weaken by the axle hole obviously. On the modal analysis
of vibration, this method can simulates accurately the natural frequencies and corresponding modalities of mirror. And
the results from three-face aluminous mirror indicate that the resonance points of a new mirror may be guaranteed
existing in selected speed range.
The numerical analysis method for the surface deformation of rotating mirrors were presented based on the
three-dimensional elastic mechanics and the computational techniques of finite element in this manuscript. With this
method, the surface deformation curves of rotating mirrors including multi-surfaces from three to eight, aluminous, steel,
and beryllium ones were calculated. A result was obtained that surface patterns of a mirror in operation are primarily
dependent on the amount of surfaces and the axial hole which whether or not exists for aluminous and steel mirrors, but
it rests with the amount of surfaces as well as Poisson's ratio for a beryllium mirror with so tiny Poisson's ratio. This
conclusion is different from that of forerunner.
KEYWORDS: Objectives, Distortion, Imaging systems, High speed photography, High speed cameras, Photography, Photogrammetry, Data processing, Resistance, Data centers
This paper deals with the approaching surveying principle and data processing for launching and taking-off of a large
means of delivery; moreover, the special requirements of the drift magnitude surveying optical system, the intermittent
performance of the synchronous high speed camera, the high speed tracing and accurate measurement of angles, and the
synchronous controlling, are also described. The approching survey means here the surveying range from the surveying
facility to the launching tower is about 100m~200m.
The theories and technologies of the optomechanical high speed photography, which has basically met the requirements
in investigations of high speed, ultrahigh speed and other top scientific phenomena, have been developed and
improved these years in China. Compared with the high speed photography with converter tube, the optomechanical high
speed photography has a higher spacial resolution, larger image, and more frames since it only need one transfer from
optical image to chemical image or charge image.
Optomechanical high speed photographic techniques include high speed optics and mechanics, high speed
optoelectronics, high speed electrooptical shutter, and high speed opto-optical technique. In this paper, we will introduce
the technologies of high speed transporting film photography, ultrahigh speed rotating mirror photography, multiframe
high speed photography with solid imaging unit, microscopy high speed photography, raster principle and Cranz-Schardin principle in high speed photography, and extreme high speed photography based on optical principles.
We investigated the group-velocity dispersion of a one dimensional uniform photonic crystal by the optical transmission method. For application in optical communications, the wavelength should be near one of the two edges of a photonic bandgap. Four kinds of
dispersion-compensation may be obtained with a photonic crystal. Huge negative and positive group-velocity-dispersion (GVD) about a
zero-dispersion-point as large as 5.1 Tera- ps/nm/km by a photonic crystal of 100 periods can be realized. Such a value is about 50 Giga times the GVD of conventional dispersion-compensation fibers. The GVD reaches a maximum when the optical length ratio of the high refractive index material to the low refractive index material is 1.2 for given operating parameters. When we keep the optical length of each layer being constant, the GVD is found to increase rapidly with the refractive index ration of the high refractive index material to the low one and even more rapidly with the number of periods of a photonic crystal. Under quite common operating parameters, a thin piece of photonic crystal of 100 periods may play the role of an ordinary dispersion-compensation fiber with a length over 158
kilo-meters.
We propose a kind of planar photonic crystal micro-cavity which is truly two-dimensional and is composed of a line of periodic air-holes and a set of periodic air grooves both with defect. Unlike the photonic crystal micro-cavity formed by distributed Bragg reflection (DBR) layers and two dimensional holes in a semiconductor substrate, the micro-cavity proposed is a true two-dimensional planar structure that is easy for mass-production through die-press copying. Numerical simulations by the FDTD method show that there exist resonance modes inside the photonic bandgap. The resonance wavelength is mainly decided by the period and radius of the holes. The quality factor of the cavity is mainly decided by the number of periods of the holes and the grooves.
In this paper we try to perfect information theory of high speed photography (HSP), which are theoretically and practically analyzed with theory on degree of freedom (DOF). Generally speaking, information theory of HSP should be able to used for evaluating HSP systems and HSP methods, and for the best it should be able to show the way to upgrade HSP's performances and throughly exploits resources of the recording light used as information carrier. As a method for studying information theory of HSP, optical DOF theory should be utilized at first, in which particularities of HSP systems, statistical rules of measured events and know-how from long-term HSP’s practices must be taken into consideration.
A key to implement tubeless extreme high speed photography (EHSP) is to ask for help from parallel processing of light and to exploit different light properties: amplitude, phase, polarization, wavelength, wave vector, even photon spin and photon mode. Holography is an important technique to implement multi-frame EHSP, because a hologram is a result derived from contributions of multiple light merits. In this paper, techniques to implement holography-based EHSP are described, including mechanism of generating multiple frames and extreme high photographic rate.
A rotating mirror is a kernel unit in a Miller-type high speed camera, which is both as an imaging element in optical path and as an element to implement ultrahigh speed photography. According to Schardin’s Principle, information capacity of an ultrahigh speed camera with rotating mirror depends on primary wavelength of lighting used by the camera and limit linear velocity on edge of the rotating-mirror: the latter is related to material (including specifications in technology), cross-section shape and lateral structure of rotating mirror. In this manuscript dynamic behavior of high strength aluminium alloy rotating mirrors is studied, from which it is preliminarily shown that an aluminium alloy rotating mirror can be absolutely used as replacement for a steel rotating-mirror or a titanium alloy rotating-mirror in framing photographic systems, and it could be also used as a substitute for a beryllium rotating-mirror in streak photographic systems.
We investigate a complex cavity composed of three simple cavities, which are formed by three simple defects in a one-dimensional photonic crystal (PC), by the optical transmission method. We set two of the simple cavities to be the same, and let the cavity-length of the third one vary. Generally, two or more narrow resonant transmission modes emerge in the bandgap region; the position of one of them is basically fixed with different fine structures, in which exists a fixed crest, while the other modes wander in the bandgap region as the cavity-length of the third cavity varies. We find the optimized the relative coupling length being 0.447 for the complex cavity. Introducing the parameter - degree of rectangularity, we find that the complex PC cavity is much more close to an ideal narrow band-pass filter than a simple PC defect cavity. It is surprising that the degree of rectangularity is insensitive to the number of periods in the structures.
Up to date, all of recording surface of rotating mirror framing cameras has been a cylindrical surface with a circular cross section fitted the inherent transcendental image locus, which is named the classical substitution circle theory that is not perfect and hard obtaining good results because of the principle errors. However, in this paper a new advanced designing theory of rotating mirror framing cameras, substituted for the classical theory and proven very useful and available to simultaneously get non-defocusing image recording, coaxial imaging for all relay lenses and equispeed sweeping, has been developed.
Model S-150 ultra-high speed framing camera with continuous access, characterized by a three faced, high velocity motor driven rotating mirror of aluminum substratum with a reflective overcoat made direct coating or transposition coating, a coaxial speed increaser with ratio of 2 x 13:1, a pre-magnetic-field fast open shutter with opening speed of 0.7 mm/μs, and a computer-electronic camera control with virtual buttons substituted for tens of real buttons and real monitoring of whole photographic process, has successfully been made. Specifications of the camera are as follows: the maximum economical photographic rate of 1.4 x 106 pps and the maximum rate of 2.24 x 106 pps corresponding to a rotating mirror velocity of 4 x 105 rpm and its peripheral velocity of 800 mps, the dynamic visual resolution of 34 lp/mm along the temporal direction, the frame format of 14 mm x 20 mm. Tests and experiments verify that it is very useful and available with high quality pictures taken from the transient events with random triggering time and very strong anti-interference property.
The transmission theory of laser polarization is applied to the electro-optical switching system. The polarization transmission matrix in Electro-optical switching system is given. The switching property through the system is analyzed.
Most of recording surfaces of rotating mirror cameras is a cylindrical surface with a circular cross section fitted the inherent transcendental image locus, But now, the circular substituted for the transcendental curve is not necessary because of a great deal progress of manufacturing these transcendental curves; therefore, designing the advanced recording surfaces can be put into effect: the fine recording surface on which both the defocus magnitudes and uncertainty of writing speed are minimum, the non-defocus recording surface, and the constant writing speed recording surface.
In order to study the metal target surface in-place deformation induced by the laser beam or other ones effecting upon, three kinds of measuring dynamic in-plane deformation techniques by means of a laser speckle, which are the speckle field time sequence processing (that is the optical flow analysis of speckle pattern), the digital speckle pattern processing (in fact, it is a kind of pattern or picture enhancement technique), and the digital speckle pattern correlation metrology, have been studded and developed. The latter, the correlation metrology, has been made a big progress: better precision and higher processing speed.
In this paper, the new binary optical even device is presented. Whose phase depth exceeded 2(pi) . This device has the characteristics of less weight, convenient adjusting, high utilization rate of energy and well- distributed light beam, which can be used in quasi-molecule laser exposure system.
Based on the mathematical analysis for optics of the laser scanning system, the mechanisms of the graphic distortion in the laser display has been studied. After considering the beam trace from image plan to galvanometer, a relation between the image points on the screen and the scan angles was built. Thus, it has been able to rectify the scanning linear distortion and pincushion error by computer software effectively.
The copper ion laser generates CW UV (248 - 272 nm) and near IR (780 nm) laser radiation. This laser is usually excited by hollow cathode discharge. In recent years, a new discharge, so-called capacitively coupled radio frequency (CCRF) discharge has been employed to pump the metal ion laser, in order to increase laser efficiency and improve its discharge stability and the lifetime of the laser. In this paper, the principle and nature of the CCRF discharge, and its application for the copper ion laser are reviewed.
In process of making several new kinds of high speed intermittent camera, in order to obtain the perfect frame stability which is important for good quality of the pictures, the film-down-rushing law and equistroke film transporting have been studied, theoretically and experimentally.
The copper ion laser supplies interesting CW UV emission in the region 248 - 270 nm. It is possible to realize VUV (-160 nm) laser oscillation in the copper ion laser. Its discharge characteristics, laser gain and output performance in dependence on the operating conditions have been investigated. A UV laser gain of 4.72%/m and a quasi-CW power of 700 mW without the optimum of the output coupling have been measured. The processes in laser plasma can be described and the experimental results were good explained with a theoretical model presented by the author.
In order to get multi-frame holograms in high speed holography, studying the framing principle is very
important. The essential way is to code reference beam which is one of the three necessary conditions to make
hologram. Coding reference beam by means of a grating is available and convenient. This paper describes three kinds
of grating coded reference to carry out multi-frame holography: the grating spectrum framing, the grating orientation
framing, and the time delaying framing combined with the grating orientation.
During experimentally researching the time behavior of a intermittent film-transport force, we found a different form than those given by domestic and abroad researchers, the film-transport force is not continuous. In this paper, the dynamic model of the intermittent film-transport has been established on the basis of practical film-transport and the approximate assumptions, from which we derived the film- transport force equation, simulated the film moving process in the film road on computer, and showed out the explanations to the experimental results.
This paper describes a new optical method, the high speed Moire topography of the shadow, to measure the yaw angle of a free-flight projectile, in which, the equipment can be simplified, for it needs only one camera, but the older ones need at least two. The formula of the calculation are deduced and the errors are analyzed. The final experimental results of a free-flight projectile by the new method mentioned above show that the yaw angle of a free-flight projectile can be measured accurately with the dynamic Moire topography of the surface of the projectile. This new method is available.
The soft x-ray time-resolved spectroscopy is composed of a soft x-ray spectroscopic head and a soft x-ray streak camera. Because the soft x-ray spectroscopic head possesses a spectral resolution of 0.1 angstrom, the performances of the whole system mainly depend on the characteristics of the soft x-ray streak camera. In this paper, therefore, the design features and characterization of the soft x-ray streak camera are mainly described. In order to record the spectrum ranging from 30 angstroms to 230 angstroms on a limited photocathode slit length, the whole camera including the photocathode can be shifted along the spectrum without dismantling the camera from the soft x-ray generating chamber. The soft x-ray streak image tube possesses a specially designed vacuum-tight valve, which could be closed or opened in the vacuum chamber operated by a step motor, to prevent the photocathode sensitive to soft x- ray and internal intensified microchannel plate from pollution by water vapor or dust in the atmosphere. In order to test its dynamic performances, a soft x-ray diode was developed. The dynamic testing shows that the temporal resolution of this camera is 5 ps, which is limited by our soft x-ray source, dynamic spatial resolution is 20 lp/mm which implies the spectral resolution of 0.25 angstroms. Because of using CsI or KI photocathode deposited on a 1000 angstrom thick parylence film, the spectral responses range is approximately 0.05 to 10 KeV.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.