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Thickness measurement of an opaque optics using a cyclic path optical configuration (CPOC) setup and polarization phase shifting interferometry (PPSI) is presented. The CPOC setup is used to simultaneously focus two orthogonally polarized counterpropagating converging beams at its hypotenuse arm. The opaque optics is placed at the hypotenuse arm of the CPOC setup such that one of its surfaces reflects back one of the counterpropagating focusing beams. Because of the thickness of the opaque optics, the other focusing beam suffers a longitudinal shift in the beam focus. Applying PPSI, the longitudinal shift in the beam focus which is twice the thickness of the opaque optics is determined. The results obtained for a silicon plate of thickness 0.660 mm with a measurement uncertainty of 0.013 mm are presented. 相似文献
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As the feature size decreases, degradation of image quality caused by wavefront aberrations of projection optics in lithographic tools has become a serious problem in the low-k1 process. We propose a novel measurement technique for in situ characterizing aberrations of projection optics in lithographic tools. Considering the impact of the partial coherence illumination, we introduce a novel algorithm that accurately describes the pattern displacement and focus shift induced by aberrations. Employing the algorithm, the measurement condition is extended from three-beam interference to two-, three-, and hybrid-beam interferences. The experiments are performed to measure the aberrations of projection optics in an ArF scanner. 相似文献
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Nicolle M Fusco T Michau V Rousset G Beuzit JL 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(9):2233-2245
Multiconjugate adaptive optics is one of the major challenges in adaptive optics. It requires the measurement of the volumic distribution of the turbulence. Two wavefront sensing (WFS) concepts have been proposed to perform the wavefront analysis for such systems: the star-oriented and layer-oriented approaches. We give a performance analysis and a comparison of these two concepts in the framework of the simplest of the multi-guide-star adaptive optics systems, that is, ground layer adaptive optics. A phase-related criterion is proposed to assess analytically the performance of both concepts. This study highlights the main advantages and drawbacks of each WFS concept and shows how it is possible to optimize the concepts with respect to the signal to noise ratio on the phase measurement. A comparison of their optimized versions is provided and shows that one can expect very similar performance with the two optimized concepts. 相似文献
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Gilles L Vogel CR Ellerbroek BL 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(9):1817-1822
We introduce a multigrid preconditioned conjugate-gradient (MGCG) iterative scheme for computing open-loop wave-front reconstructors for extreme adaptive optics systems. We present numerical simulations for a 17-m class telescope with n = 48756 sensor measurement grid points within the aperture, which indicate that our MGCG method has a rapid convergence rate for a wide range of subaperture average slope measurement signal-to-noise ratios. The total computational cost is of order n log n. Hence our scheme provides for fast wave-front simulation and control in large-scale adaptive optics systems. 相似文献
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Booth MJ 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2007,365(1861):2829-2843
The imaging properties of optical microscopes are often compromised by aberrations that reduce image resolution and contrast. Adaptive optics technology has been employed in various systems to correct these aberrations and restore performance. This has required various departures from the traditional adaptive optics schemes that are used in astronomy. This review discusses the sources of aberrations, their effects and their correction with adaptive optics, particularly in confocal and two-photon microscopes. Different methods of wavefront sensing, indirect aberration measurement and aberration correction devices are discussed. Applications of adaptive optics in the related areas of optical data storage, optical tweezers and micro/nanofabrication are also reviewed. 相似文献
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Homoelle D Bowers MW Budge T Haynam C Heebner J Hermann M Jancaitis K Jarboe J LaFortune K Salmon JT Schindler T Shaw M 《Applied optics》2011,50(22):4382-4388
We have undertaken a measurement campaign to determine the repeatability of the prompt flashlamp-induced wavefront aberration on beamlines at the National Ignition Facility (NIF) and determine the extent to which shot-to-shot variations in this aberration may degrade the performance of a proposed adaptive optics system for the short-pulse Advanced Radiographic Capability beamline on NIF. In this paper we will describe the unique NIF configuration that was required to make this measurement, present the results of the experiment, and discuss the implications of these results for the adaptive optics system design. 相似文献
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Looze DP 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(9):2850-2863
The standard adaptive optics system can be viewed as a sampled-data feedback system with a continuous-time disturbance (the incident wavefront from the observed object) and discrete-time measurement noise. A common measure of the performance of adaptive optics systems is the time average of the pupil variance of the residual wavefront. This performance can be related to that of a discrete-time system obtained by lifting the incident and residual wavefronts. The corresponding discrete-time model is derived, and the computation of the adaptive optics system residual variance is based on that model. The predicted variance of a single mode of an adaptive optics system is shown to be the same as that obtained via simulation (as expected). The discrete-time prediction is also shown to be superior to a continuous-time approximation of the adaptive optics system. 相似文献
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CaF2 is one of the dominating optical materials used for ArF excimer laser optics. Surface quality of optically finished CaF2 plays an important role in the components' lifetime. A variable angle spectroscopic ellipsometry was employed to evaluate surface quality of optically finished CaF2 in terms of top surface and subsurface damage. The subsurface damage was revealed by removing the top surface. Combining plasma ion assisted deposition and ellipsometric measurement, a dense smooth F-SiO2 film was developed to prevent fluorine loss of CaF2 optics under ArF excimer laser irradiation, leading to an extended lifetime. In addition, an integrated protective coating approach was established on fluoride multilayer coated CaF2 optics, resulting in environmentally stable optical performance. 相似文献
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As a critical dimension shrinks, the degradation in image quality caused by wavefront aberrations of projection optics in lithographic tools becomes a serious problem. It is necessary to establish a technique for a fast and accurate in situ aberration measurement. We introduce what we believe to be a novel technique for characterizing the aberrations of projection optics by using an alternating phase-shifting mask. The even aberrations, such as spherical aberration and astigmatism, and the odd aberrations, such as coma, are extracted from focus shifts and image displacements of the phase-shifted pattern, respectively. The focus shifts and the image displacements are measured by a transmission image sensor. The simulation results show that, compared with the accuracy of the previous straightforward measurement technique, the accuracy of the coma measurement increases by more than 30% and the accuracy of the spherical-aberration measurement increases by approximately 20%. 相似文献
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An in-line type compact micropulse lidar (MPL) with an annular beam was developed for low-altitude cloud measurement. An optical circulator and a couple of axicon prisms for an annular beam were installed on the lidar optics. The advantage of using the in-line MPL is its ability to obtain a near-range measurement with a narrow field of view of 0.1 mrad and to obtain a depolarization measurement of the orthogonally polarized echoes caused by ice crystals of a low-altitude cloud. The total insertion loss of the lidar optics was 3 dB. Detectors such as avalance photodiode detectors can be operated in an analog mode near the breakdown voltage because of the high isolation of the optical circulator. The ideal lidar echo variation from the nearest distance was verified by measuring the mountain echoes at various distances. The depolarization measurement of a low-altitude ice cloud was also demonstrated. 相似文献
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Gutierrez-Martinez C. Sanchez-Rinza B. Rodriguez-Asomoza J. Pedraza-Contreras J. 《IEEE transactions on instrumentation and measurement》2000,49(1):32-36
The implementation of an automated system for analysis of coherence length of light and for the measurement of optical delays is reported. This type of measurement is very important for designing coherence-modulated optical transmission systems. Such systems have been studied for the last few years as new potential high-speed optical links useful for point-to-point, local area networks, and bidirectional transmissions, at optical wavelengths around 1300 nm. The main characteristics of coherence-modulated transmissions include the need of using low-coherence optical sources and integrated optics lithium niobate (LiNbO3) electro-optic retarders. This paper describes the implementation of an automated system allowing the measurement of coherence lengths of semiconductor optical sources and also optical delays as essential data for designing coherence-modulated optical links. The reported results include characterization of commercial low-coherence semiconductor optical sources and integrated optics coherence modulators 相似文献
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Abstract The well-known schemes for simultaneous measurement of canonically conjugate variables in quantum optics based on beam-splitting, amplification and heterodyning are analysed in the Heisenberg picture. It is shown that the operators representing the measured observables share a common structure. The measured phase-space probability is a non-negative smoothed Wigner function. 相似文献
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T. Jigami M. Kobayashi Y. Taguchi Y. Nagasaka 《International Journal of Thermophysics》2007,28(3):968-979
A nanoscale thermal system design, especially for the precise measurement of the temperature distribution in microfabricated
devices using novel nanomaterials such as carbon nanotubes and fullerene has become increasingly important along with the
development of nanotechnology. A new approach has been proposed toward an optical nanoscale temperature measurement method
using near-field optics and fluorescence thermometry, namely, Fluor-NOTN (fluorescent near-field optics thermal nanoscopy).
The topographic image and temperature dependence of a fluorescently modified sample, excited by near-field light, are simultaneously
monitored. In this article, the temperature dependence of Cy3 fluorescent dye is verified near room temperature (298–308 K).
A Cy3 mono-dispersed sample of a permalloy (Ni81Fe19) wire heater, 500 nm in width and 100 nm in thickness, is designed and fabricated. A localized temperature gradient of ΔT = 4 K within a submicron distance from the heater was successfully detected by near-field fluorescence with 100 nm spatial
resolution. 相似文献
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Abstract Using the method of quantum trajectories we show that a known pure state can be optimally monitored through time when subject to a sequence of discrete measurements. By modifying the way that we extract information from the measurement apparatus we can minimize the average algorithmic information of the measurement record, without changing the unconditional evolution of the measured system. We define an optimal measurement scheme as one which has the lowest average algorithmic information allowed. We also show how it is possible to extract information about system operator averages from the measurement records and their probabilities. The optimal measurement scheme, in the limit of weak coupling, determines the statistics of the variance of the measured variable directly. We discuss the relevance of such measurements for recent experiments in quantum optics. 相似文献
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Burns SA Tumbar R Elsner AE Ferguson D Hammer DX 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(5):1313-1326
We describe the design and performance of an adaptive optics retinal imager that is optimized for use during dynamic correction for eye movements. The system incorporates a retinal tracker and stabilizer, a wide-field line scan scanning laser ophthalmoscope (SLO), and a high-resolution microelectromechanical-systems-based adaptive optics SLO. The detection system incorporates selection and positioning of confocal apertures, allowing measurement of images arising from different portions of the double pass retinal point-spread function (psf). System performance was excellent. The adaptive optics increased the brightness and contrast for small confocal apertures by more than 2x and decreased the brightness of images obtained with displaced apertures, confirming the ability of the adaptive optics system to improve the psf. The retinal image was stabilized to within 18 microm 90% of the time. Stabilization was sufficient for cross-correlation techniques to automatically align the images. 相似文献
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动态波前相位的高分辨率测量 总被引:4,自引:0,他引:4
动态波前相位信息测量是大气光学,气动光学和激光技术等领域的重要实验手段。提出了一种具有高的时间和空间分辨率以及长的测量持续时间的动态波前相位测量方法。应用Hartmann-Shack波前传感器获得高空间分辨率的相位信息,采用高帧频CCD摄象机获得高时间分辨率图象数据。 相似文献