在微波或可见/IR波长下工作的望远镜系统的性能通常根据波长范围用不同的参数来描述。大多数商业射线跟踪软件包都是专门为可见光/红外系统设计的，因此，尽管非常灵活和复杂，但不能提供适当的参数来充分描述微波天线，从而无法与规格进行比较。在这项工作中，我们证明了斯特列尔比等于相位效率时，切趾因子被考虑在内。相位效率是影响天线口径效率的最关键因素，也是望远镜设计中最难优化的参数。斯特列尔比和相位效率之间的等效性使望远镜的设计者/用户有机会使用更快的商业射线跟踪软件来优化设计。我们还讨论了几个测试的结果，以检查这种关系的有效性，我们进行了使用射线跟踪软件，ZEMAX和一个完整的物理光学软件，GRASP9.3，适用于三个不同的望远镜设计，跨越一个因素的$\simeq 10 in terms of D/lambda. The maximum measured discrepancy between phase efficiency and Strehl ratio varies between $ \simeq 0.4和1.9高达一个偏移角>40束，这取决于光学配置，但在斯特列尔比>0.95的情况下，它总是小于0.5。
英文摘要：
The performance of telescope systems working at microwave or visible/IR wavelengths is typically described in terms of different parameters according to the wavelength range. Most commercial ray tracing packages have been specifically designed for use with visible/IR systems and thus, though very flexible and sophisticated, do not provide the appropriate parameters to fully describe microwave antennas, and thus to compare with specifications. In this work we demonstrate that the Strehl ratio is equal to the phase efficiency when the apodization factor is taken into account. The phase efficiency is the most critical contribution to the aperture efficiency of an antenna, and the most difficult parameter to optimize during the telescope design. The equivalence between the Strehl ratio and the phase efficiency gives the designer/user of the telescope the opportunity to use the faster commercial ray-tracing software to optimize the design. We also discuss the results of several tests performed to check the validity of this relationship that we carried out using a ray-tracing software, ZEMAX and a full Physical Optics software, GRASP9.3, applied to three different telescope designs that span a factor of $\simeq 10 in terms of D/lambda. The maximum measured discrepancy between phase efficiency and Strehl ratio varies between $\simeq 0.4 and 1.9 up to an offset angle of >40 beams, depending on the optical configuration, but it is always less than 0.5 where the Strehl ratio is >0.95.
Imaging X-rays by direct focusing offers greater sensitivity and a higher dynamic range compared to techniques based on indirect imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a sounding rocket payload that uses seven sets of nested Wolter-I figured mirrors to observe the Sun in hard X-rays through direct focusing. Characterizing the performance of these optics is critical to optimize their performance and to understand their resulting data. In this paper, we present a ray-tracing simulation we created and developed to study Wolter-I X-ray mirrors. We validated the accuracy of the …
The third part of the paper is devoted to ray tracing in optical resonators. The employed method for dealing with the issue uses the elliptical or hyperbolic rotations that Wigner distributions associated with optical fields undergo during propagation from one spherical mirror of a resonator to the other. It is illustrated by various examples concerning meridional or skew rays, reentrant in stable resonators or propagating in unstable resonators. A classification of optical resonators is eventually deduced.
Phase-shifting technique for improving the imaging capacity of sparse-aperture optical interferometers
在本文中，我们描述了一个多孔径干涉仪的原理，使用相移技术，并适用于快速，快照成像的天体物理对象在极端的角分辨率通过傅立叶反演。所提出的设计的几个优点突出，其中包括辐射效率，领域的Fizeau干涉仪，和一个初步的校准程序，允许表征仪器误差。对于大的望远镜数量，所提出的设计也导致在相当大的简化的光学和机械设计。数值模拟表明，仅使用传统光学组件或新兴技术，就可以将数百台望远镜耦合到单个4K x 4K探测器阵列上。
CMB-S4 -- the next-generation ground-based cosmic microwave background (CMB) experiment - will significantly advance the sensitivity of CMB measurements and improve our understanding of the origin and evolution of the universe. CMB-S4 will deploy large-aperture telescopes fielding hundreds of thousands of detectors at millimeter wavelengths. We present the baseline optical design concept of the large-aperture CMB-S4 telescopes, which consists of two optical configurations: (i) a new off-axis, three-mirror, free-form anastigmatic design and (ii) the existing coma-corrected crossed-Dragone desig…
The numerical aperture (NA) of a lens determines its ability to focus light and its resolving capability. Having a large NA is a very desirable quality for applications requiring small light-matter interaction volumes or large angular collections. Traditionally, a large NA lens based on light refraction requires precision bulk optics that ends up being expensive and is thus also a specialty item. In contrast, metasurfaces allow the lens designer to circumvent those issues producing high NA lenses in an ultra-flat fashion. However, so far, these have been limited to numerical apertures on the s…
Analytical decomposition of Zernike and hexagonal modes over an hexagonal segmented optical aperture
ONERA The French Aerospace Laboratory（法国航空航天实验室）；Aix Marseille Université, CNRS, CNES, Laboratoire d’Astrophysique de Marseille (LAM)（艾克斯马赛大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学）
Metalenses, artificially engineered subwavelength nanostructures to focus light within ultrathin thickness, promise potential for a paradigm shift of conventional optical devices. However, the aperture sizes of metalenses are usually bound within hundreds of micrometers by the commonly-used scanning-based fabrication methods, limiting their usage on practical optical devices like telescopes. Here, for the first time, we demonstrate a high-efficiency, single-lens, refractive metalens telescope. We developed a mass production-friendly workflow for fabricating wafer-scale (80-mm aperture) metalen…
Tomographic volumetric additive manufacturing (VAM) is an optical 3D printing technique where an object is formed by photopolymerizing resin via tomographic projections. Currently, these projections are calculated using the Radon transform from computed tomography but it ignores two fundamental properties of real optical projection systems: finite etendue and non-telecentricity. In this work, we introduce 3D ray tracing as a new method of computing projections in tomographic VAM and demonstrate high fidelity printing in non-telecentric and higher etendue systems, leading to a 3X increase in ve…
We propose a feedback-assisted direct laser writing method to perform laser ablation of fiber optics devices in which their light-collection signal is used to optimize their properties. A femtosecond-pulsed laser beam is used to ablate a metal coating deposited around a tapered optical fiber, employed to show the suitability of the approach to pattern devices with small radius of curvature. During processing, the same pulses generate two-photon fluorescence in the surrounding environment and the signal is monitored to identify different patterning regimes over time through spectral analysis. T…
Radiation of charged particles moving in the presence of dielectric targets is of significant interest for various applications in the accelerator and beam physics. The size of these targets is typically much larger than the wavelengths under consideration. This fact gives us an obvious small parameter of the problem and allows developing approximate methods for analysis. We develop two methods, which are called the "ray optics method" and the "aperture method". In the present paper, we apply these methods to analysis of Cherenkov radiation from a charge moving through a vacuum channel in a so…
We demonstrate a three-dimensional (3D) optical diffraction tomographic technique with optimal frequency combination (OFC-ODT) for the 3D quantitative phase imaging of unlabeled specimens. Three sets of through-focus intensity images are captured under an annular aperture and two circular apertures with different coherence parameters. The 3D phase optical transfer functions (POTF) corresponding to different illumination apertures are combined to obtain an optimally synthesized frequency response, achieving high-quality, low-noise 3D reconstructions with imaging resolution up to the incoherent …
One of the important advantages of optical metasurfaces over conventional diffractive optical elements is their capability to efficiently deflect light by large angles. However, metasurfaces are conventionally designed using approaches that are optimal for small deflection angles and their performance for designing high numerical aperture devices is not well quantified. Here we introduce and apply a technique for the estimation of the efficiency of high numerical aperture metasurfaces. The technique is based on a particular coherent averaging of diffraction coefficients of periodic blazed grat…
Extended depth of focus (EDOF) optics can enable lower complexity optical imaging systems when compared to active focusing solutions. With existing EDOF optics, however, it is difficult to achieve high resolution and high collection efficiency simultaneously. The subwavelength pitch of meta-optics enables engineering very steep phase gradients, and thus meta-optics can achieve both a large physical aperture and high numerical aperture. Here, we demonstrate a fast (f/1.75) EDOF meta-optic operating at visible wavelengths, with an aperture of 2 mm and focal range from 3.5 mm to 14.5 mm (286 diop…
We present the design, fabrication, and measured performance of metamaterial Anti-Reflection Cuttings (ARCs) for large-format alumina filters operating over more than an octave of bandwidth to be deployed on the Simons Observatory (SO). The ARC consists of sub-wavelength features diced into the optic's surface using a custom dicing saw with near-micron accuracy. The designs achieve percent-level control over reflections at angles of incidence up to 20$^\circ$. The ARCs were demonstrated on four 42 cm diameter filters covering the 75-170 GHz band and a 50 mm diameter prototype covering the 200-…
Synthetic aperture radar (SAR) can measure the phase with antenna and microwave, which cannot be directly extended to visible light imaging due to phase lost. In this letter, we reported an active remote sensing with visible light via reflective Fourier ptychography (FP), termed coherent synthetic aperture imaging (CSAI), achieving high resolution, wide field-of-view (FOV) and phase recovery. A proof-of-concept experiment was reported with laser scanning and a collimator for the infinite object. Both smooth and rough objects are tested, and the spatial resolution increased from 15.6 um to 3.48…
