Misalignment sensing with a moiré beat signal for nanolithography

2020 ◽  
Vol 45 (7) ◽  
pp. 1762
Author(s):  
Nan Wang ◽  
Wei Jiang ◽  
Yu Zhang
Keyword(s):  
Beat Signal

scholarly journals Estimation bounds of beat signal in the R-Mode localization system

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Lars Grundhofer ◽  
Stefan Gewies ◽  
Giovanni Del Galdo
Keyword(s):  
Beat Signal ◽  
Mode Localization ◽  
Localization System

scholarly journals Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lars Liebermeister ◽  
Simon Nellen ◽  
Robert B. Kohlhaas ◽  
Sebastian Lauck ◽  
Milan Deumer ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Continuous Wave ◽  
Dynamic Range ◽  
Terahertz Spectroscopy ◽  
Beat Signal ◽  
Photonic Integration ◽  
Terahertz Time Domain Spectroscopy ◽  
Destructive Testing ◽  
Optical Delay ◽  
Broadband Terahertz

AbstractBroadband terahertz spectroscopy enables many promising applications in science and industry alike. However, the complexity of existing terahertz systems has as yet prevented the breakthrough of this technology. In particular, established terahertz time-domain spectroscopy (TDS) schemes rely on complex femtosecond lasers and optical delay lines. Here, we present a method for optoelectronic, frequency-modulated continuous-wave (FMCW) terahertz sensing, which is a powerful tool for broadband spectroscopy and industrial non-destructive testing. In our method, a frequency-swept optical beat signal generates the terahertz field, which is then coherently detected by photomixing, employing a time-delayed copy of the same beat signal. Consequently, the receiver current is inherently phase-modulated without additional modulator. Owing to this technique, our broadband terahertz spectrometer performs (200 Hz measurement rate, or 4 THz bandwidth and 117 dB peak dynamic range with averaging) comparably to state-of-the-art terahertz-TDS systems, yet with significantly reduced complexity. Thickness measurements of multilayer dielectric samples with layer-thicknesses down to 23 µm show its potential for real-world applications. Within only 0.2 s measurement time, an uncertainty of less than 2 % is achieved, the highest accuracy reported with continuous-wave terahertz spectroscopy. Hence, the optoelectronic FMCW approach paves the way towards broadband and compact terahertz spectrometers that combine fiber optics and photonic integration technologies.

Metrological characteristics of the frequency method for measuring the viscosity of magnetorheological fluids in a rotary viscometer

2020 ◽  
pp. 28-33
Author(s):  
E.S. Belyaev ◽  
A.V. Vanyagin ◽  
B.A. Gordeev ◽  
V.I. Erofeev ◽  
S.N. Okhulkov
Keyword(s):  
Dynamic Viscosity ◽  
Torsion Angle ◽  
Viscoelastic Medium ◽  
Twist Angle ◽  
Magnetorheological Fluid ◽  
Magnetorheological Fluids ◽  
Metrological Characteristics ◽  
Beat Signal ◽  
Frequency Method ◽  
Rotary Viscometer

A frequency method for measuring the dynamic viscosity of rheological media is described using the example of a magnetorheological fluid. The method is based on the principle of operation of a rotary viscometer, in which the torsion angle depends on the characteristics of the viscoelastic medium. Keywords frequency method, dynamic viscosity, torque, beat signal, methodical error, resolution, accuracy, twist angle, torsion. [email protected]; [email protected]

Characteristics Analysis of the Photons Arrival Time Interval of Laser Beat Signal

2012 ◽  
Vol 32 (4) ◽  
pp. 0403001 ◽  
Author(s):  
刘立生 Liu Lisheng ◽  
张合勇 Zhang Heyong ◽  
赵帅 Zhao Shuai ◽  
郭劲 Guo Jin
Keyword(s):  
Arrival Time ◽  
Beat Signal ◽  
Time Interval ◽  
Characteristics Analysis

Influence of Light Source Stability on Evolution of Beat Signal in Nonlinear Photonic Crystal Fibers

2009 ◽  
Vol 36 (4) ◽  
pp. 895-900
Author(s):  
张丽梅 Zhang Limei ◽  
王智 Wang Zhi ◽  
余贶琭 Yu Kuanglu ◽  
吴重庆 Wu Chongqing
Keyword(s):  
Photonic Crystal ◽  
Light Source ◽  
Photonic Crystal Fibers ◽  
Beat Signal ◽  
Nonlinear Photonic Crystal ◽  
Crystal Fibers

Study on Beat Signal with High Signal-to-Noise Ratio in Terahertz Frequency Measurement

2017 ◽  
Vol 44 (6) ◽  
pp. 0604006
Author(s):  
杨奕 Yang Yi ◽  
孙青 Sun Qing ◽  
邓玉强 Deng Yuqiang ◽  
冯美琦 Feng Meiqi ◽  
赵昆 Zhao Kun
Keyword(s):  
Signal To Noise Ratio ◽  
Frequency Measurement ◽  
Beat Signal ◽  
High Signal ◽  
Terahertz Frequency ◽  
Signal To Noise ◽  
Noise Ratio

scholarly journals Miniature Fiber-Optic Magnetic Field Sensor Based on Ampere Force and Fiber Laser

2020 ◽  
Vol 10 (4) ◽  
pp. 291-297
Author(s):  
Weiren Cheng ◽  
Tianming Luo ◽  
Linghao Cheng ◽  
Hao Liang ◽  
Bai-ou Guan
Keyword(s):  
Magnetic Field ◽  
Fiber Laser ◽  
Fiber Optic ◽  
Copper Wire ◽  
Beat Signal ◽  
Magnetic Field Sensor ◽  
Frequency Change ◽  
Dual Frequency ◽  
Ampere Force ◽  
Field Sensor

Abstract A compact fiber-optic magnetic field sensor is proposed by packaging an orthogonal dual-frequency fiber grating laser and a copper wire with alternating electrical current together inside epoxy resin. The alternating current generates Ampere force in a magnetic field, which changes the birefringence of the fiber laser and hence tunes the frequency of the beat signal after photodetection. The magnetic field magnitude can then be detected by measuring the frequency change of the beat signal. The sensitivity of the sensor can be tuned with a maximum response of 35.21 kHz/kGs demonstrated. Moreover, the sensor shows good immunity to environment interference.

scholarly journals MIMO FM-CW radar using beat signal averaging method

2020 ◽  
Author(s):  
Asiah Maryam Md Noor ◽  
Idnin Pasya ◽  
Nur Emileen Abd Rashid ◽  
Raja Syamsul Azmir Raja Abdullah
Keyword(s):  
Averaging Method ◽  
Beat Signal ◽  
Signal Averaging ◽  
Cw Radar
Sign in / Sign up

Export Citation Format

Share Document