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Related papers: Focal ratio degradation in lightly-fused hexabundl…

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New multi-core imaging fibre bundles -- hexabundles -- being developed at the University of Sydney will provide simultaneous integral field spectroscopy for hundreds of celestial sources across a wide angular field. These are a natural…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 J. J. Bryant , J. W. O'Byrne , J. Bland-Hawthorn , S. G. Leon-Saval

Focal Ratio Degradation (FRD) in fibres is a crucial factor to control in astronomical instruments in order to minimize light loss. As astronomical instrumentation has advanced, the integration of large populations of fibres has become…

Instrumentation and Methods for Astrophysics · Physics 2023-06-30 Weimin Sun , Xudong Chen , Jiabin Wang , Hang Jiang , Anzhi Wang , Qi Yan , Zhenyu Ma , Shengjia Wang , Tao Geng , Yue Zhong , Zhongquan Qu , Yunxiang Yan

The performance of fiber-fed astronomical spectrographs is highly influenced by the properties of fibers. The near-field and far-field scrambling characteristics have a profound impact on the line spread function (LSF) of the spectra. Focal…

Instrumentation and Methods for Astrophysics · Physics 2024-08-16 Man-Yin Leo Lee , Zhiheng Lin , Chit-Ho Hui , Renbin Yan , YiuHung Cheung , Horace Tsz-Hong Hung , Matthew A. Bershady , Sabysachi Chattopadhyay , Michael P. Smith

We present a new method of DEEM, the direct energy encircling method, for characterising the performance of fibres in most astronomical spectroscopic applications. It's a versatile platform to measure focal ratio degradation (FRD),…

Instrumentation and Methods for Astrophysics · Physics 2019-12-25 Yunxiang Yan , Qi Yan , Gang Wang , Weimin Sun , A-Li Luo , Zhenyu Ma , Qiong Zhang , Jian Li , Shuqing Wang

The performance of highly-multiplexed spectrographs is limited by focal degradation (FRD) in the optical fibres. It has already been shown that this is caused mainly by processes concentrated around the mounting points at the ends of the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Jeremy Allington-Smith , Colin Dunlop , Graham Murray , Ulrike Lemke

We present a new way to mitigate focal-ratio degradation (FRD) when using optical fibers to transport multimode light. Our approach exploits a custom multicore fiber (MCF) with six dissimilar cores that are single mode at ~1550 nm…

We demonstrate a novel technology that combines the power of the multi-object spectrograph with the spatial multiplex advantage of an integral field spectrograph (IFS). The Sydney-AAO Multi-object IFS (SAMI) is a prototype wide-field system…

We present measurements of how multimode fiber focal-ratio degradation (FRD) and throughput vary with levels of fiber surface polish from 60 to 0.5 micron grit. Measurements used full-beam and laser injection methods at wavelengths between…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Arthur D. Eigenbrot , Matthew A. Bershady , Corey M. Wood

We demonstrate the imaging capability of a frequency modulated continuous wave lidar based on a fiber bundle. The lidar constructs velocity and range images for hard targets at a rate of 60 Hz. The sensing range is up to 30 m with 20 mW of…

Instrumentation and Detectors · Physics 2024-10-28 Iskander Gazizov , Sergei Zenevich , Alexander Rodin

While optical fibers display excellent performances in the infrared, visible and ultraviolet ranges remain poorly addressed by them. Obtaining better fibers for the short-wavelength range has been restricted, in all fiber optics, by…

Modal noise is a common source of noise introduced to the measurements by optical fibres and is particularly important for fibre-fed spectroscopic instruments, especially for high-resolution measurements. This noise source can limit the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-16 D. P. Sablowski , D. Plüschke , M. Weber , K. G. Strassmeier , A. Järvinen

Lensless flexible fiber-bundle based endoscopes allow imaging at depths beyond the reach of conventional microscopes with a minimal footprint. These multicore fibers provide a simple solution for widefield fluorescent imaging when the…

Optics · Physics 2020-08-26 Noam Shekel , Ori Katz

Focal ratio degradation (FRD) is a major contributor to throughput and light loss in a fibre spectroscopic telescope system. We combine the guided mode theory in geometric optics and a well-known model, power distribution model (PDM), to…

Instrumentation and Methods for Astrophysics · Physics 2019-12-25 Yunxiang Yan , Gang Wang , Weimin Sun , A-Li Luo , Zhenyu Ma , Jian Li , Shuqing Wang

Fourier ptychographic microscopy (FPM) is a powerful computational imaging modality that achieves high space-bandwidth product imaging for biomedical samples. However, its adoption is limited by slow data acquisition due to the need for…

Optics · Physics 2025-09-09 Shi Zhao , Haowen Zhou , Changhuei Yang

Focal Ration Degradation (FRD) is a change in light angular distribution caused by fiber optics. FRD is important to fiber-fed, spectroscopic astronomical systems because it can cause loss of signal, degradation in spectral resolution, or…

Fiber-based confocal endomicroscopy has shown great promise for minimally-invasive deep-tissue imaging. Despite its advantages, confocal fiber-bundle endoscopy inherently suffers from undersampling due to the spacing between fiber cores,…

Optics · Physics 2023-05-25 Gil Weinberg , Uri Weiss , Ori Katz

Optical fibres are essential for many types of highly-multiplexed and precision spectroscopy. The success of the new generation of multifibre instruments under construction to investigate fundamental problems in cosmology, such as the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Jeremy Allington-Smith , Graham Murray , Ulrike Lemke

We report on extensive testing carried out on the optical fibers for the VIRUS instrument. The primary result of this work explores how 10+ years of simulated wear on a VIRUS fiber bundle affects both transmission and focal ratio…

Perhaps surprisingly, the total electron microscopy (EM) data collected to date is less than a cubic millimeter. Consequently, there is an enormous demand in the materials and biological sciences to image at greater speed and lower dosage,…

Computer Vision and Pattern Recognition · Computer Science 2016-12-06 Suhas Sreehari , S. V. Venkatakrishnan , Katherine L. Bouman , Jeffrey P. Simmons , Lawrence F. Drummy , Charles A. Bouman

We describe the optimum telescope focal ratio for a two-element, three surface, telecentric image-transfer microlens-to-fiber coupled integral field unit within the constraints imposed by micro-optics fabrication and optical aberrations. We…

Instrumentation and Methods for Astrophysics · Physics 2022-05-09 Sabyasachi Chattopadhyay , Matthew A. Bershady , Marsha J. Wolf , Michael P. Smith
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