scholarly journals Accurate reconstruction of electric field of ultrashort laser pulse with complete two-step phase-shifting

2019 ◽  
Vol 7 ◽  
Author(s):  
Yi Cai ◽  
Zhenkuan Chen ◽  
Shuiqin Zheng ◽  
Qinggang Lin ◽  
Xuanke Zeng ◽  
...  
Keyword(s):  
Electric Field ◽  
Signal To Noise Ratio ◽  
Spectral Width ◽  
Phase Shifting ◽  
Optical Fields ◽  
Optical Components ◽  
Ultrafast Optical ◽  
Operating Stability ◽  
Balanced Detection ◽  
Ultrashort Laser

This paper presents a complete two-step phase-shifting (TSPS) spectral phase interferometry for direct electric-field reconstruction (SPIDER) to improve the reconstruction of ultrafast optical fields. Here, complete TSPS acts as a balanced detection that can not only remove the effect of the dc term of the interferogram, but also reduce measurement noises, and thereby improve the capability of SPIDER to measure the pulses with narrow spectra or complex spectral structures. Some prisms are chosen to replace some environment-sensitive optical components, especially reflective optics to improve operating stability and improve signal-to-noise ratio further. Our experiments show that the available shear can be decreased to 1.5% of the spectral width, which is only about $1/3$ compared with traditional SPIDER.

scholarly journals Meta-Deflectors Made of Dielectric Nanohole Arrays with Anti-Damage Potential

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jingjun Wu ◽  
Zao Yi ◽  
Xin Ye ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Laser Cutting ◽  
High Complexity ◽  
Damage Potential ◽  
Optical Components ◽  
Nanohole Arrays ◽  
Intense Light ◽  
Polarization Of Light ◽  
Air Hole

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm2. The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.

scholarly journals Tunable control of antibody immobilization using electric field

2015 ◽  
Vol 112 (7) ◽  
pp. 1995-1999 ◽  
Author(s):  
Sam Emaminejad ◽  
Mehdi Javanmard ◽  
Chaitanya Gupta ◽  
Shuai Chang ◽  
Ronald W. Davis ◽  
...  
Keyword(s):  
Solid State ◽  
Electric Field ◽  
Signal To Noise Ratio ◽  
Physical Adsorption ◽  
Antibody Immobilization ◽  
Proof Of Concept ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sensing Platforms ◽  
Glass Surfaces

The controlled immobilization of proteins on solid-state surfaces can play an important role in enhancing the sensitivity of both affinity-based biosensors and probe-free sensing platforms. Typical methods of controlling the orientation of probe proteins on a sensor surface involve surface chemistry-based techniques. Here, we present a method of tunably controlling the immobilization of proteins on a solid-state surface using electric field. We study the ability to orient molecules by immobilizing IgG molecules in microchannels while applying lateral fields. We use atomic force microscopy to both qualitatively and quantitatively study the orientation of antibodies on glass surfaces. We apply this ability for controlled orientation to enhance the performance of affinity-based assays. As a proof of concept, we use fluorescence detection to indirectly verify the modulation of the orientation of proteins bound to the surface. We studied the interaction of fluorescently tagged anti-IgG with surface immobilized IgG controlled by electric field. Our study demonstrates that the use of electric field can result in more than 100% enhancement in signal-to-noise ratio compared with normal physical adsorption.

A New Method Using Chirp-Matching OPCPA Scheme for Improving Signal-to-Noise Ratio of Ultrashort Laser Pulse

2011 ◽  
Vol 31 (7) ◽  
pp. 0719001
Author(s):  
曾曙光 Zeng Shuguang ◽  
张彬 Zhang Bin ◽  
李现华 Li Xianhua ◽  
孙年春 Sun Nianchun ◽  
隋展 Sui Zhan
Keyword(s):  
Laser Pulse ◽  
Ultrashort Laser Pulse ◽  
Signal To Noise Ratio ◽  
New Method ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Ultrashort Laser

Study of the Correction of Effects Chromatic Dispersion and Attenuation to Evaluate the Optical Transmission

2020 ◽  
Vol 41 (2) ◽  
pp. 209-214
Author(s):  
Saliha Kheris ◽  
Badra Bouabdallah
Keyword(s):  
Optical Transmission ◽  
Signal To Noise Ratio ◽  
Chromatic Dispersion ◽  
Optical Amplifier ◽  
Laser Source ◽  
Long Distance ◽  
Optical Components ◽  
Optical Detector ◽  
Fiber Optical ◽  
Dispersion And Attenuation

AbstractIn this paper, we have presented a global study of simple bonds, focusing on the main limitations introduced by different optical components as laser source, fiber, optical amplifier, and optical detector. The construction of a long-distance link requires the compensation of attenuation and chromatic dispersion phenomena. Thus, it is well known that the attenuations cause the drop of the signal intensity, whereas the pulse spreading, due to the dispersion, causes the increase of the Bit Error Rate (BER) and consequently the reduction of the signal to noise ratio (SNR). In this purpose, we have calculated the quality factor (Q) issues from the noisy signal’s simulations. We have found a Q of 7.02 to a BER of 0.8 e−12. The founding results match well with fixes norms in telecommunication field.

scholarly journals Fringe Phase-Shifting Field Based Fuzzy Quotient Space-Oriented Partial Differential Equations Filtering Method for Gaussian Noise-Induced Phase Error

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5202 ◽  
Author(s):  
Yu ◽  
Ji ◽  
Xue ◽  
Wang
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Gaussian Noise ◽  
Quotient Space ◽  
Signal To Noise Ratio ◽  
Phase Error ◽  
Phase Shifting ◽  
Signal To Noise ◽  
Partial Differential ◽  
Filtering Method

Traditional filtering methods only focused on improving the peak signal-to-noise ratio of the single fringe pattern, which ignore the filtering effect on phase extraction. Fringe phase-shifting field based fuzzy quotient space-oriented partial differential equations filtering method is proposed to reduce the phase error caused by Gaussian noise while filtering. First, the phase error distribution that is caused by Gaussian noise is analyzed. Furthermore, by introducing the fringe phase-shifting field and the theory of fuzzy quotient space, the modified filtering direction can be adaptively obtained, which transforms the traditional single image filtering into multi-image filtering. Finally, the improved fourth-order oriented partial differential equations with fidelity item filtering method is established. Experiments demonstrated that the proposed method achieves a higher signal-to-noise ratio and lower phase error caused by noise, while also retaining more edge details.

scholarly journals Wind and turbulence measurements by the Middle and Upper Atmosphere Radar (MUR): comparison of techniques

2004 ◽  
Vol 22 (11) ◽  
pp. 3843-3862 ◽  
Author(s):  
A. A. Praskovsky ◽  
E. A. Praskovskaya ◽  
G. Hassenpflug ◽  
M. Yamamoto ◽  
S. Fukao
Keyword(s):  
Correlation Function ◽  
Momentum Flux ◽  
Signal To Noise Ratio ◽  
Spectral Width ◽  
Upper Atmosphere ◽  
Turbulent Velocity ◽  
Comparison Of Techniques ◽  
Horizontal Momentum ◽  
Degree Variances ◽  
Beam Broadening

Abstract. The structure-function-based method (referred to as UCAR-STARS), a technique for estimating mean horizontal winds, variances of three turbulent velocity components and horizontal momentum flux was applied to the Middle and Upper atmosphere Radar (MUR) operating in spaced antenna (SA) profiling mode. The method is discussed and compared with the Holloway and Doviak (HAD) correlation-function-based technique. Mean horizontal winds are estimated with the STARS and HAD techniques; the Doppler Beam Swinging (DBS) method is used as a reference for evaluating the SA techniques. Reasonable agreement between SA and DBS techniques is found at heights from 5km to approximately 11km, where signal-to-noise ratio was rather high. The STARS and HAD produced variances of vertical turbulent velocity are found to be in fair agreement. They are affected by beam-broadening in a different way than the DBS-produced spectral width, and to a much lesser degree. Variances of horizontal turbulent velocity components and horizontal momentum flux are estimated with the STARS method, and strong anisotropy of turbulence is found. These characteristics cannot be estimated with correlation-function-based SA methods, which could make UCAR-STARS a useful alternative to traditional SA techniques.

scholarly journals Simultaneous optical, CUTLASS HF radar, and FAST spacecraft observations: signatures of boundary layer processes in the cusp

2004 ◽  
Vol 22 (2) ◽  
pp. 511-525 ◽  
Author(s):  
K. Oksavik ◽  
F. Søraas ◽  
J. Moen ◽  
R. Pfaff ◽  
J. A. Davies ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Broad Band ◽  
Spectral Width ◽  
Hf Radar ◽  
Optical Data ◽  
Low Energy Electrons ◽  
Field Lines ◽  
Auroral Phenomena ◽  
Electric Fields And Currents

Abstract. In this paper we discuss counterstreaming electrons, electric field turbulence, HF radar spectral width enhancements, and field-aligned currents in the southward IMF cusp region. Electric field and particle observations from the FAST spacecraft are compared with CUTLASS Finland spectral width enhancements and ground-based optical data from Svalbard during a meridional crossing of the cusp. The observed 630nm rayed arc (Type-1 cusp aurora) is associated with stepped cusp ion signatures. Simultaneous counterstreaming low-energy electrons on open magnetic field lines lead us to propose that such electrons may be an important source for rayed red arcs through pitch angle scattering in collisions with the upper atmosphere. The observed particle precipitation and electric field turbulence are found to be nearly collocated with the equatorward edge of the optical cusp, in a region where CUTLASS Finland also observed enhanced spectral width. The electric field turbulence is observed to extend far poleward of the optical cusp. The broad-band electric field turbulence corresponds to spatial scale lengths down to 5m. Therefore, we suggest that electric field irregularities are directly responsible for the formation of HF radar backscatter targets and may also explain the observed wide spectra. FAST also encountered two narrow highly structured field-aligned current pairs flowing near the edges of cusp ion steps. Key words. Ionosphere (electric fields and currents). Magnetosphere physics (magnetopause, cusp, and boundary layers; auroral phenomena)

scholarly journals Optimal run-and-tumble–based transportation of a Janus particle with active steering

2017 ◽  
Vol 114 (13) ◽  
pp. E2580-E2589 ◽  
Author(s):  
Tomoyuki Mano ◽  
Jean-Baptiste Delfau ◽  
Junichiro Iwasawa ◽  
Masaki Sano
Keyword(s):  
Electric Field ◽  
Signal To Noise Ratio ◽  
Thermal Fluctuations ◽  
Janus Particle ◽  
Active Steering ◽  
Angular Velocities ◽  
Orientation Vector ◽  
Run And Tumble ◽  
Feedback Algorithm ◽  
Individual Particles

Although making artificial micrometric swimmers has been made possible by using various propulsion mechanisms, guiding their motion in the presence of thermal fluctuations still remains a great challenge. Such a task is essential in biological systems, which present a number of intriguing solutions that are robust against noisy environmental conditions as well as variability in individual genetic makeup. Using synthetic Janus particles driven by an electric field, we present a feedback-based particle-guiding method quite analogous to the “run-and-tumbling” behavior of Escherichia coli but with a deterministic steering in the tumbling phase: the particle is set to the run state when its orientation vector aligns with the target, whereas the transition to the “steering” state is triggered when it exceeds a tolerance angle α. The active and deterministic reorientation of the particle is achieved by a characteristic rotational motion that can be switched on and off by modulating the ac frequency of the electric field, which is reported in this work. Relying on numerical simulations and analytical results, we show that this feedback algorithm can be optimized by tuning the tolerance angle α. The optimal resetting angle depends on signal to noise ratio in the steering state, and it is shown in the experiment. The proposed method is simple and robust for targeting, despite variability in self-propelling speeds and angular velocities of individual particles.

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