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200 papers

Accurate perception of dynamic obstacles is essential for autonomous robot navigation in indoor environments. Although sophisticated 3D object detection and tracking methods have been investigated and developed thoroughly in the fields of…

Robotics · Computer Science 2025-03-03 Zhefan Xu , Haoyu Shen , Xinming Han , Hanyu Jin , Kanlong Ye , Kenji Shimada

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution,…

Optics · Physics 2023-06-05 Hui Yuan , Alvydas Lisauskas , Mark D. Thomson , Hartmut G. Roskos

The SINFONI instrument for ESO's VLT combines integral field spectroscopy and adaptive optics (AO). We discuss detailed simulations of the adaptive optics module. These simulations are aimed at assessing the AO module performance,…

Astrophysics · Physics 2009-11-10 Anthony G A Brown , Enrico Fedrigo , Paul van der Werf

We present significantly improved proper motion measurements of the Milky Way's central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the…

Astrophysics of Galaxies · Physics 2015-05-20 Sylvana Yelda , Jessica R. Lu , Andrea M. Ghez , Will Clarkson , Jay Anderson , Tuan Do , Keith Matthews

With the LIGO announcement of the first direct detection of gravitational waves (GWs), the GW Astronomy was formally ushered into our age. After one-hundred years of theoretical investigation and fifty years of experimental endeavor, this…

Instrumentation and Methods for Astrophysics · Physics 2016-12-06 Wei-Tou Ni , Sen Han , Tao Jin

The recent development of electron sensitive and pixelated detectors has attracted the use of four-dimensional scanning transmission electron microscopy (4D-STEM). Here, we present a precession electron diffraction assisted 4D-STEM…

Instrumentation and Detectors · Physics 2021-10-04 Jiwon Jeong , Niels Cautaerts , Gerhard Dehm , Christian H. Liebscher

Wave front sensing of the surface of equal phase for a propagating electromagnetic wave is a vital technology in fields ranging from real time adaptive optics, to high accuracy metrology, to medical optometry. We have developed a new method…

Optics · Physics 2025-10-01 C. L. Carilli , L. Torino , B. Nikolic , N. Thyagarajan , U. Iriso

There are scientific and technological needs to improve the co-phasing of the primary mirrors of segmented telescopes. We have developed a methodology for using the wavefront sensor of an adaptive optics (AO) system to disentangle the phase…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Benjamin Calvin , Michael Fitzgerald , Sam Ragland

The National Ignition Facility (NIF) requires that pulses from each of the 192 laser beams be positioned on target with an accuracy of 50 um rms. Beam quality must be sufficient to focus a total of 1.8 MJ of 0.351-um light into a…

Instrumentation and Detectors · Physics 2007-05-23 Lewis Van Atta , Mark Perez , Richard Zacharias , William Rivera

We present recent results obtained with the VLT/MUSE Integral Field Spectrograph fed by the 4LGSF and its laser tomography adaptive optics module GALACSI. While this so-called narrow-field mode of MUSE was not designed to perform directly…

Over the last two decades, spatial light modulators (SLMs) have revolutionised our ability to shape optical fields. They grant independent dynamic control over thousands of degrees-of-freedom within a single light beam. In this work we test…

A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Yitping Kok , Michael J. Ireland , J. Gordon Robertson , Peter G. Tuthill , Benjamin A. Warrington , William J. Tango

Consumer-grade camera systems often struggle to maintain stable image quality under complex illumination conditions such as low light, high dynamic range, and backlighting, as well as spatial color temperature variation. These issues lead…

Computer Vision and Pattern Recognition · Computer Science 2025-10-24 Fuchen Li , Yansong Du , Wenbo Cheng , Xiaoxia Zhou , Sen Yin

High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus. We propose an accurate, efficient and easy to implement…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Olivier Guyon , Taro Matsuo , Roger Angel

The term wavefront sensor refers to the entire class of devices capable of measuring the optical wavefront of the incoming beam. Although numerous solutions have been proposed so far, recent advances in structured light have opened new…

A new wavefront sensing approach, derived from the successful curvature wavefront sensing concept but using a non-linear phase retrieval wavefront reconstruction scheme, is described. The non-linear curvature wavefront sensor (nlCWFS)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Olivier Guyon

We study the challenging problem of unsupervised multi-object segmentation on single images. Existing methods, which rely on image reconstruction objectives to learn objectness or leverage pretrained image features to group similar pixels,…

Computer Vision and Pattern Recognition · Computer Science 2025-06-03 Yafei Yang , Zihui Zhang , Bo Yang

We describe a fast closed-loop optimization wavefront shaping system able to focus light through dynamic scattering media. A MEMS-based spatial light modulator (SLM), a fast photodetector and FPGA electronics are combined to implement a…

Instrumentation and Detectors · Physics 2018-02-14 Baptiste Blochet , Laurent Bourdieu , Sylvain Gigan

The main objective of the present project is to explore the viability of an adaptive optics control system based exclusively on Field Programmable Gate Arrays (FPGAs), making strong use of their parallel processing capability. In an…

Instrumentation and Methods for Astrophysics · Physics 2018-07-03 Avinash Surendran , Mahesh P. Burse , A. N. Ramaprakash , Padmakar Parihar

We demonstrated a CMOS imaging system that adapts each pixel's exposure and sampling rate to capture high dynamic range (HDR) videos. The system consist of a custom designed image sensor with pixel-wise exposure configurability and a…

Image and Video Processing · Electrical Eng. & Systems 2019-06-25 Jie , Zhang , Jonathan P. Newman , Xiao Wang , Chetan Singh Thakur , John Rattray , Ralph Etienne-Cummings , Matthew A. Wilson