Scrambling and modal noise mitigation in the Habitable Zone Planet Finder fiber feed

2014 ◽  
Author(s):  
Arpita Roy ◽  
Samuel Halverson ◽  
Suvrath Mahadevan ◽  
Lawrence W. Ramsey
Keyword(s):  
Habitable Zone ◽  
Noise Mitigation ◽  
Modal Noise

Modal Noise Mitigation in 850-nm VCSEL-Based Transmission Systems Over Single-Mode Fiber

2016 ◽  
Vol 64 (10) ◽  
pp. 3342-3350 ◽  
Author(s):  
Jacopo Nanni ◽  
Simone Rusticelli ◽  
Carlos Viana ◽  
Jean-Luc Polleux ◽  
Catherine Algani ◽  
...  
Keyword(s):  
Single Mode ◽  
Single Mode Fiber ◽  
Noise Mitigation ◽  
Transmission Systems ◽  
Modal Noise

Fiber modal noise mitigation by a rotating optical double scrambler

2020 ◽  
Author(s):  
Gert Raskin ◽  
Jacob Pember ◽  
Dmytro Rogozin ◽  
Christian Schwab ◽  
David W. Coutts
Keyword(s):  
Noise Mitigation ◽  
Modal Noise

scholarly journals Modal noise mitigation for high-precision spectroscopy using a photonic reformatter

2020 ◽  
Vol 497 (3) ◽  
pp. 3713-3725
Author(s):  
F A Pike ◽  
A Benoît ◽  
D G MacLachlan ◽  
R J Harris ◽  
I Gris-Sánchez ◽  
...  
Keyword(s):  
Near Infrared ◽  
Broad Band ◽  
Single Mode ◽  
M Dwarfs ◽  
Noise Mitigation ◽  
Excitation Light ◽  
Single Mode Fibre ◽  
Spread Function ◽  
Potential Applications ◽  
Modal Noise

ABSTRACT Recently, we demonstrated how an astrophotonic light reformatting device, based on a multicore fibre photonic lantern and a 3D waveguide component, can be used to efficiently reformat the point spread function of a telescope to a diffraction-limited pseudo-slit. Here, we demonstrate how such a device can also efficiently mitigate modal noise – a potential source of instability in high-resolution multimode fibre-fed spectrographs. To investigate the modal noise performance of the photonic reformatter, we have used it to feed light into a bench-top near-infrared spectrograph (R ≈ 7000, λ ≈ 1550 nm). One approach to quantifying the modal noise involved the use of broad-band excitation light and a statistical analysis of how the overall measured spectrum was affected by variations in the input coupling conditions. This approach indicated that the photonic reformatter could reduce modal noise by a factor of 6 when compared to a multimode fibre with a similar number of guided modes. Another approach to quantifying the modal noise involved the use of multiple spectrally narrow lines, and an analysis of how the measured barycentres of these lines were affected by variations in the input coupling. Using this approach, the photonic reformatter was observed to suppress modal noise to the level necessary to obtain spectra with stability close to that observed when using a single mode fibre feed. These results demonstrate the potential of using photonic reformatters to enable efficient multimode spectrographs that operate at the diffraction-limit and are free of modal noise, with potential applications including radial velocity measurements of M-dwarfs.

Modal noise mitigation in a photonic lantern fed near-IR spectrograph

2020 ◽  
Author(s):  
Fraser A. Pike ◽  
Aurélien Benoît ◽  
David G. MacLachlan ◽  
Robert J. Harris ◽  
Itandehui Gris-Sánchez ◽  
...  
Keyword(s):  
Noise Mitigation ◽  
Near Ir ◽  
Modal Noise

scholarly journals Modal Noise Mitigation through Fiber Agitation for Fiber-fed Radial Velocity Spectrographs

2018 ◽  
Vol 853 (2) ◽  
pp. 181 ◽  
Author(s):  
Ryan R. Petersburg ◽  
Tyler M. McCracken ◽  
Dominic Eggerman ◽  
Colby A. Jurgenson ◽  
David Sawyer ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Noise Mitigation ◽  
Modal Noise

scholarly journals Fiber modal noise mitigation by a rotating double scrambler

2020 ◽  
Author(s):  
Gert Raskin ◽  
Dmytro Rogozin ◽  
Tom Mladenov ◽  
Christian Schwab ◽  
David W. Coutts
Keyword(s):  
Noise Mitigation ◽  
Modal Noise

scholarly journals Artificial Neural Network Assisted Error Correction for MLC NAND Flash Memory

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 879
Author(s):  
Ruiquan He ◽  
Haihua Hu ◽  
Chunru Xiong ◽  
Guojun Han
Keyword(s):  
Neural Network ◽  
Error Correction ◽  
Error Detection ◽  
Flash Memory ◽  
Nand Flash ◽  
Data Reliability ◽  
Nand Flash Memory ◽  
Process Technology ◽  
Noise Mitigation ◽  
Memory Channel

The multilevel per cell technology and continued scaling down process technology significantly improves the storage density of NAND flash memory but also brings about a challenge in that data reliability degrades due to the serious noise. To ensure the data reliability, many noise mitigation technologies have been proposed. However, they only mitigate one of the noises of the NAND flash memory channel. In this paper, we consider all the main noises and present a novel neural network-assisted error correction (ANNAEC) scheme to increase the reliability of multi-level cell (MLC) NAND flash memory. To avoid using retention time as an input parameter of the neural network, we propose a relative log-likelihood ratio (LLR) to estimate the actual LLR. Then, we transform the bit detection into a clustering problem and propose to employ a neural network to learn the error characteristics of the NAND flash memory channel. Therefore, the trained neural network has optimized performances of bit error detection. Simulation results show that our proposed scheme can significantly improve the performance of the bit error detection and increase the endurance of NAND flash memory.

Acoustic meta-silencer: Toward enabling ultrawide-band air-permeable noise barrier

2021 ◽  
pp. 107754632110011
Author(s):  
Mohammad Javad Khodaei ◽  
Amin Mehrvarz ◽  
Reza Ghaffarivardavagh ◽  
Nader Jalili
Keyword(s):  
Heat Transfer ◽  
Design Methodology ◽  
Heat Transfer Performance ◽  
Transmission Loss ◽  
Design Parameters ◽  
Transfer Performance ◽  
Noise Mitigation ◽  
Acoustic Cavity ◽  
Road Map ◽  
Noise Barrier

In this article, we have first presented a metasurface design methodology by coupling the acoustic cavity to the coiled channel. The geometrical design parameters in this structure are subsequently studied both analytically and numerically to identify a road map for silencer design. Next, upon tuning the design parameters, we have introduced an air-permeable noise barrier capable of sound silencing in the ultrawide band of the frequency. It is has been shown that the presented metasurface can achieve +10 dB sound transmission loss from 170 Hz to 1330 Hz (≈3 octaves). Furthermore, we have numerically studied the ventilation and heat transfer performance of the designed metasurface. Enabling noise mitigation by leveraging the proposed metasurface opens up new possibilities ranging from residential and office noise reduction to enabling ultralow noise fan, propellers, and machinery.

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