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Transparent objects are widely used in our daily lives, making it important to teach robots to interact with them. However, it's not easy because the reflective and refractive effects can make depth cameras fail to give accurate geometry…

Computer Vision and Pattern Recognition · Computer Science 2024-02-20 Tutian Tang , Jiyu Liu , Jieyi Zhang , Haoyuan Fu , Wenqiang Xu , Cewu Lu

We have developed a method to measure the mirror reflectivity of telescopes. While it is relatively easy to measure the local reflectivity of the mirror material, it is not so straightforward to measure the amount of light that it focuses…

Astrophysics · Physics 2008-11-26 R. Mirzoyan , M. Garczarczyk , J. Hose , D. Paneque

Reflective membrane mirrors provide a lightweight, low-cost alternative to traditional optics for next-generation large-aperture telescopes, but their non-rigid, thin structure poses challenges for surface metrology. We present a…

Instrumentation and Methods for Astrophysics · Physics 2025-11-17 Xin Yan , Zhi-Kang Zhuang , Fu-Jia Du , Wen Duan , Peilin Yin , Mo-Nong Yu , Guang Yang

Recent advances in twistor theory are applied to geometric optics in ${\Bbb{R}}^3$. The general formulae for reflection of a wavefront in a surface are derived and in three special cases explicit descriptions are provided: when the…

Differential Geometry · Mathematics 2021-11-15 Brendan Guilfoyle , Wilhelm Klingenberg

Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we revisit the classical method of probing such waves (wavelengths of the order of mm) as well as inherent properties of liquids and liquid films…

Optics · Physics 2009-11-11 Tarun Kr. Barik , Partha Roy Chaudhuri , Anushree Roy , Sayan Kar

We report on a recently developed laser-probing diagnostic which allows direct measurements of ray-deflection angles in one axis, whilst retaining imaging capabilities in the other axis. This allows us to measure the spectrum of angular…

The detection of spatial or temporal variations in very thin samples has important applications in the biological sciences. For example, cellular membranes exhibit changes in lipid composition and order, which in turn modulate their…

Accurately measuring the geometry and spatially-varying reflectance of real-world objects is a complex task due to their intricate shapes formed by concave features, hollow engravings and diverse surfaces, resulting in inter-reflection and…

Computer Vision and Pattern Recognition · Computer Science 2024-12-16 Jing Yang , Pratusha Bhuvana Prasad , Qing Zhang , Yajie Zhao

Images are the standard input for vision algorithms, but one-shot infield reflectance measurements are creating new opportunities for recognition and scene understanding. In this work, we address the question of what reflectance can reveal…

Computer Vision and Pattern Recognition · Computer Science 2016-07-12 Hang Zhang , Kristin Dana , Ko Nishino

A shearing interferometer is presented which uses polarization control to shear the wavefront and to modulate the interference pattern. The shear is generated by spatial walk-off in a birefringent crystal. By adjusting the orientation of…

Optics · Physics 2012-12-11 Peter Beyersdorf , Mark Cordier

We investigate the interaction between an infinite cylinder and a free fluid-fluid interface governed only by its surface tension. We study the deformation of an initially flat interface when it is deformed by the presence of a cylindrical…

Soft Condensed Matter · Physics 2012-08-15 Christophe Raufaste , Geoffroy Kirstetter , Franck Celestini , Simon Cox

Direct and noninvasive measurement of the pressure distribution in test sections of a micro-channel is a challenging, if not an impossible, task. Here, we present an analytical method for extracting the pressure distribution in a deformable…

Fluid Dynamics · Physics 2013-10-09 O. Ozsun , V. Yakhot , K. L. Ekinci

We have implemented a multi-functional optofluidic sensor that can monitor changes in the refractive index and pressure of biofluid simultaneously and can detect free-solution molecular interaction in-situ. In this paper, we demonstrate two…

Optics · Physics 2014-10-16 Zhida Xu , Logan Liu

In this paper we show how students can measure optical features of smartphone displays through three experiments. Observing diffraction patterns from smartphone displays allows students to determine the Pixels Per Inch (PPI). Observing…

Physics Education · Physics 2025-11-26 Mamatha Ramanjineyulu Maddur , Hemansh Shah , Praveen Pathak

Understanding the optical properties of various components in water Cherenkov (WC) neutrino experiments is essential for accurate detector characterization, which is critical for precise measurements. Of particular importance is the…

Instrumentation and Detectors · Physics 2025-05-12 Deepak Tiwari

For measurements designed to accurately determine layer thickness, there is a natural trade-off between sensitivity to optical thickness and lateral resolution due to the angular ray distribution required for a focused beam. We demonstrate…

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…

Astrophysics · Physics 2009-11-07 Henry G. Roe

The goal of this work is to make progress in the domain of near-wall velocimetry. The technique we use is based on the tracking of nanoparticles in an evanescent field, close to a wall, a technique called TIRF (Total Internal Reflection…

We propose an approach to simulate and render realistic water animation from a single still input photograph. We first segment the water surface, estimate rendering parameters, and compute water reflection textures with a combination of…

Graphics · Computer Science 2022-10-07 Ryusuke Sugimoto , Mingming He , Jing Liao , Pedro V. Sander

This paper introduces depth estimation from water drops. The key idea is that a single water drop adhered to window glass is totally transparent and convex, and thus optically acts like a fisheye lens. If we have more than one water drop in…

Computer Vision and Pattern Recognition · Computer Science 2016-04-05 Shaodi You , Robby T. Tan , Rei Kawakami , Yasuhiro Mukaigawa , Katsushi Ikeuchi