scholarly journals The Effect of a Dominant Initial Single Mode on the Kelvin–Helmholtz Instability Evolution: New Insights on Previous Experimental Results

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Assaf Shimony ◽  
Dov Shvarts ◽  
Guy Malamud ◽  
Carlos A. Di Stefano ◽  
Carolyn C. Kuranz ◽  
...  
Keyword(s):  
Vortex Dynamics ◽  
Single Mode ◽  
Mixing Zone ◽  
Helmholtz Instability ◽  
Initial Spectrum ◽  
Laser Facility ◽  
Order Of Magnitude ◽  
Initial Seed ◽  
Vortex Merger ◽  
Initial Mode

This paper brings new insights on an experiment, measuring the Kelvin–Helmholtz (KH) instability evolution, performed on the OMEGA-60 laser facility. Experimental radiographs show that the initial seed perturbations in the experiment are of multimode spectrum with a dominant single-mode of 16 μm wavelength. In single-mode-dominated KH instability flows, the mixing zone (MZ) width saturates to a constant value comparable to the wavelength. However, the experimental MZ width at late times has exceeded 100 μm, an order of magnitude larger. In this work, we use numerical simulations and a statistical model in order to investigate the vortex dynamics of the KH instability for the experimental initial spectrum. We conclude that the KH instability evolution in the experiment is dominated by multimode, vortex-merger dynamics, overcoming the dominant initial mode.

scholarly journals Observation of dual-mode, Kelvin-Helmholtz instability vortex merger in a compressible flow

2017 ◽  
Vol 24 (5) ◽  
pp. 055705 ◽  
Author(s):  
W. C. Wan ◽  
G. Malamud ◽  
A. Shimony ◽  
C. A. Di Stefano ◽  
M. R. Trantham ◽  
...  
Keyword(s):  
Compressible Flow ◽  
Helmholtz Instability ◽  
Dual Mode ◽  
Vortex Merger

Research on Relationship of Polarization and Rayleigh Backscatter in Bidirectional Fiber Communication Systems

2013 ◽  
Vol 312 ◽  
pp. 625-630
Author(s):  
Yan Hong Wang ◽  
Gao Wang ◽  
Ji Liu
Keyword(s):  
Communication Systems ◽  
Polarization State ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Light Polarization ◽  
Polarization Property ◽  
Orthogonal Polarization ◽  
Fiber Communication ◽  
Order Of Magnitude ◽  
Relationship Of

In this paper, the general theory and polarization property of RB in single mode fiber is discussed. According to the theoretical analysis results, the bidirectional carrying system with a polarization rotating device for analog radio frequency (RF) signal is set up. The relationship of the system CRN and the different polarization state by the polarization rotating device is studied. The results show that the RB light polarization state of backward fiber end can keep to perpendicular to that of forward light when backward lights polarization is orthogonal forward lights polarization. So utilizing orthogonal polarization method for decreasing CRN can be carried on. The system performance is analyzed by simulation. The simulation results show that CRN of the bidirectional communication system on a single mode fiber can be inhibited by using the method and RB light can decrease by an order of magnitude.

scholarly journals Ultrashort Long-Period Fiber Gratings Inscribed on a Single-Mode Fiber for Torsion Sensing Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Marta Nespereira ◽  
João M. P. Coelho ◽  
José Manuel Rebordão
Keyword(s):  
Single Mode ◽  
Single Mode Fiber ◽  
Wavelength Shift ◽  
Fiber Grating ◽  
Long Period ◽  
Sensing Applications ◽  
High Tension ◽  
Long Period Fiber Gratings ◽  
Order Of Magnitude ◽  
Period Fiber Grating

The response of ultrashort-length CO2-induced long-period fiber grating (LPFG) sensors to torsion is reported. While engraving using CO2 laser radiation, the fiber is submitted to high tension allowing the obtainment of gratings with shorter lengths, down to 2.4 mm, which is almost one order of magnitude lower than the usual. Also, the fiber is only irradiated in one side, creating an asymmetrical profile leading to highly birefringent gratings. Sensitivity to axial twists is demonstrated, with values up to 0.15 nm/(rad/m) for the resonant wavelength shift and higher than 0.03 dBm/(rad/m) for the variation in the intensity (attenuation). Discrimination between rotation directions, clockwise and counterclockwise, was observed.

scholarly journals Seed Biologists Beware: End-of-Trial Estimation of Initial Viability May Be Error-Prone Due to Unexpected Seed Death during the Experiment

2021 ◽  
Author(s):  
Byron B. Lamont ◽  
Rosemary J. Newton ◽  
Pablo Gomez-Barreiro ◽  
Tianhua He
Keyword(s):  
Cold Storage ◽  
Standard Procedure ◽  
Seed Viability ◽  
Separate Sample ◽  
Annual Loss ◽  
Order Of Magnitude ◽  
Germination Success ◽  
Initial Seed ◽  
Different Levels

Seed viability is routinely measured on seeds that fail to germinate at the end of an experiment. Together with the number of germinants, this is used to estimate viability of the seeds at start of the experiment (i.e., initial viability) and provides the comparative basis on which germination success is determined. We used this standard procedure on 40 Leucadendron species subjected to oscillating temperatures, heat and/or smoke pre-treatments to examine the extent to which they raised germination levels above that of the untreated controls. 16 species showed significantly different levels of estimated initial seed viability between treatments when they should have been unaffected. Loss of viability during the trial was an order of magnitude greater than annual loss during cold storage, which was usually negligible. Lowest levels of estimated initial viability occurred among the poorly germinating controls and confirmed that the heat and smoke treatments had little effect on viability. Species with soil-stored seeds were more vulnerable to this artefact than those with plant-stored seeds. We caution against the routine use of end-of-trial germination and viability of ungerminated seeds as an estimate of initial viability in determining germination success of various treatments. The preference is for estimates of initial viability to be undertaken on a separate sample of seeds in association with the trial.

scholarly journals Experimental observations of turbulent mixing due to Kelvin–Helmholtz instability on the OMEGA Laser Facility

2012 ◽  
Vol 19 (9) ◽  
pp. 092702 ◽  
Author(s):  
V. A. Smalyuk ◽  
J. F. Hansen ◽  
O. A. Hurricane ◽  
G. Langstaff ◽  
D. Martinez ◽  
...  
Keyword(s):  
Turbulent Mixing ◽  
Helmholtz Instability ◽  
Laser Facility ◽  
Omega Laser

scholarly journals Observation of Single-Mode, Kelvin-Helmholtz Instability in a Supersonic Flow

2015 ◽  
Vol 115 (14) ◽  
Author(s):  
W. C. Wan ◽  
G. Malamud ◽  
A. Shimony ◽  
C. A. Di Stefano ◽  
M. R. Trantham ◽  
...  
Keyword(s):  
Supersonic Flow ◽  
Single Mode ◽  
Helmholtz Instability

scholarly journals Single Mode, Extreme Precision Doppler Spectrographs

2012 ◽  
Vol 8 (S293) ◽  
pp. 403-406 ◽  
Author(s):  
Christian Schwab ◽  
Sergio G. Leon-Saval ◽  
Christopher H. Betters ◽  
Joss Bland-Hawthorn ◽  
Suvrath Mahadevan
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Single Mode ◽  
Laser Frequency ◽  
Single Mode Fiber ◽  
Limiting Factor ◽  
Multimode Fiber ◽  
Line Spread Function ◽  
Order Of Magnitude ◽  
Novel Concept

AbstractThe ‘holy grail’ of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.

Waveguides Fabricated in Fused Silica by Germanium Ion Implantation at Varying Doses

1995 ◽  
Vol 392 ◽  
Author(s):  
Patrick W. Leech ◽  
Mark C. Ridgway
Keyword(s):  
Ion Implantation ◽  
Annealing Temperature ◽  
Single Mode ◽  
Fused Silica ◽  
Propagation Loss ◽  
Progressive Reduction ◽  
Intermediate Range ◽  
Nuclear Component ◽  
Order Of Magnitude ◽  
Channel Waveguides

AbstractThe implantation of MeV Ge3+ ions into fused silica has been used to fabricate single mode channel waveguides with a low propagation loss of 0.10–0.15 dB/cm. The loss coefficient, α, has been measured as a function of ion dose (8 × 1013 to 8 × 1016 ions/cm2) and annealing temperature (250 to 600 °C) at λ = 1300 nm. The value of cc for the as-implanted waveguides exhibited a minimum of -1.0 dB/cm at an intermediate range of dose from 8 × 1014 to 8 × 1015 ions/cm2. A progressive reduction in α occurred as the annealing temperature was increased from 300 to 500 °C. Annealing of the implanted waveguides at 500 °C for 1 h has produced an order of magnitude decrease in α to 0.1 dB/cm at 8 × 1014 ions/cm2. At doses which were outside of the intermediate range, the value of α was ≥ 10 dB/cm. This trend in α with ion dose has been attributed to the dominance of a residual nuclear component of damage after annealing.

REALIZATION OF FAST QUANTUM INFORMATION TRANSFER AND ENTANGLEMENT WITH SUPERCONDUCTING FLUX QUBITS COUPLED TO A RESONATOR

2013 ◽  
Vol 11 (04) ◽  
pp. 1350040
Author(s):  
YAWEI WANG ◽  
SHAOYAN GAO ◽  
AIPING FANG ◽  
PENGBO LI ◽  
FULI LI
Keyword(s):  
Quantum Information ◽  
Information Transfer ◽  
Operation Time ◽  
Single Mode ◽  
Second Order ◽  
Entangled State ◽  
Flux Qubits ◽  
Order Of Magnitude ◽  
Superconducting Flux Qubits ◽  
Flux Qubit

We propose a scheme of realization of fast quantum information transfer and two-qubit entangled state with two different superconducting flux qubits coupled to a single-mode resonator. In this approach, the two lowest levels of each Λ-type flux qubit serve as the logical states and a higher-energy intermediate level is used as the gate manipulation. This proposal does not require equal device parameters for the two flux qubits that is extremely difficult to achieve experimentally. In addition, neither a second-order detuning nor auxiliary qubits are required in this scheme. Moreover, there is no need to change the Rabi frequencies to satisfy the adiabatic passage. Therefore, the operation time can be shortened to 20–30 ns, which is faster by one order of magnitude compared to the schemes employing the second-order detuning technique.

Sign in / Sign up

Export Citation Format

Share Document