scholarly journals Investigation on the Differential Quadrature Fabry–Pérot Interferometer with Variable Measurement Mirrors

2020 ◽  
Vol 10 (18) ◽  
pp. 6191
Author(s):  
Yi-Chieh Shih ◽  
Pi-Cheng Tung ◽  
Wen-Yuh Jywe ◽  
Chung-Ping Chang ◽  
Lih-Horng Shyu ◽  
...  
Keyword(s):  
Measurement Procedure ◽  
Differential Quadrature ◽  
Displacement Measurement ◽  
Nonlinearity Error ◽  
Signal Distribution ◽  
Dc Offset ◽  
Common Path ◽  
Fabry Perot ◽  
Path Structure ◽  
First Time

Due to the common path structure being insensitive to the environmental disturbances, relevant Fabry–Pérot interferometers have been presented for displacement measurement. However, the discontinuous signal distribution exists in the conventional Fabry–Pérot interferometer. Although a polarized Fabry–Pérot interferometer with low finesse was subsequently proposed, the signal processing is complicated, and the nonlinearity error of sub-micrometer order occurs in this signal. Therefore, a differential quadrature Fabry–Pérot interferometer has been proposed for the first time. In this measurement system, the nonlinearity error can be improved effectively, and the DC offset during the measurement procedure can be eliminated. Furthermore, the proposed system also features rapid and convenient replacing the measurement mirrors to meet the inspection requirement in various measuring ranges. In the comparison result between the commercial and self-developed Fabry–Pérot interferometer, it reveals that the maximum standard deviation is less than 0.120 μm in the whole measuring range of 600 mm. According to these results, the developed differential Fabry–Pérot interferometer is feasible for precise displacement measurement.

scholarly journals DISTORTIONLESS SIGNALS TRANSFER THROUGH A WIRE MEDIA METASTRUCTURE

2018 ◽  
Vol 8 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Dmytro Vovchuk ◽  
Serhii Haliuk ◽  
Leonid Politanskyy
Keyword(s):  
Electromagnetic Waves ◽  
Spectral Characteristics ◽  
Wide Frequency Range ◽  
Power Transfer ◽  
Fabry Perot ◽  
Signal Distortions ◽  
Metallic Wires ◽  
The Wire ◽  
Wire Media ◽  
First Time

In the paper the development of the components of communication means is considered based on the wire metastructures. This approach is novel and quite promising due to the metamaterials provides new opportunities for the radio engineering devices such as antennas, absorbers etc. First of all it makes possible decreasing of the dimensions of devices while the characteristics stay the same or better. Here the artificially created metastructure that consists of parallel metallic wires and characterizes by a negative electric permittivity was investigated. The possibility of broadband power transfer of electromagnetic waves was demonstrated. Also, at first time, the investigation of possible signal distortions due to wave propagation through the wire medium (WM) slab was performed via analyzing of spectral characteristics. The obtained results allow applying of WM to power transfer in wide frequency range (not only at frequencies of Fabry-Perot resonant) and enhancement of weak source propagation as well as to antennas constructions due to the absence of signal distortions. One of the promising applications of such structures is the possibility of realizing of flexible screens with nanometer thickness and high resolution.

The link between developmental psychiatry and dual disorders from early attachment to first drugs abuse

2017 ◽  
Vol 41 (S1) ◽  
pp. S472-S473
Author(s):  
E. Garcia ◽  
R. Moreno ◽  
B. Tarjuelo
Keyword(s):  
Conduct Disorder ◽  
Dual Disorders ◽  
Childhood All ◽  
Common Path ◽  
Clinical Presentations ◽  
Competing Interest ◽  
First Time ◽  
Developmental Psychiatry ◽  
Different Parts

Since Dual Disorders expression was used for the first time, the old dilemma between cathegorial and dimensional grew again as a main issue because many authors wondered about its utility. The question was how far we can speak about two different entities, because doing so we are assuming comorbidity instead of a complex syndrome, with different clinical presentations (i.e. Talking about fever and cough instead of pneumonia). Child and adolescence psychiatry uses developmental psychiatry as a very useful tool to understand patients. Syndromes are seen as dynamic as patients. At the same time that patients grow their clinical presentations, evolves new symptoms or signs. We have reviewed retrospectively a group of twenty parents that were named as dual disorders, with different substance abuse but a common path in their childhood; all of them were diagnosed of ADHD and Conduct Disorder. We chose them because of the differences that DSM, ICD and main researchers have about this group, which some consider better described as a Disocial hiperquinetic disorder (ICD) than a AHDH with a conduct disorder associated (DSM), comorbidity again. We agreed with ICD opinion and will discuss how in some way we are somehow as those blind people describing different parts of the same elephant when we talk sometimes about dual. Truth is that opposite dual view or its syndromic treatment developmental psychiatry has all the time underlined the role of reward circuits/executive functions as epigenetic issues, both modulated by gene and environment.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Linear Displacement Calibration System Integrated with a Novel Auto-Alignment Module for Optical Axes

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2462 ◽  
Author(s):  
Yi-Chieh Shih ◽  
Pi-Cheng Tung ◽  
Yung-Cheng Wang ◽  
Lih-Horng Shyu ◽  
Eberhard Manske
Keyword(s):  
Machine Tools ◽  
Mechanical Engineering ◽  
Critical Issue ◽  
Linear Displacement ◽  
Engineering Industry ◽  
Operational Experience ◽  
Common Path ◽  
Fabry Perot ◽  
Optical Axes

The quality of processed workpieces is affected directly by the precision of the linear stage. Therefore, the linear displacement calibration of machine tools must be implemented before delivery and after employment for a period of time. How to perform a precise calibration with high inspection efficiency is a critical issue in the precision mechanical engineering industry. In this study, the self-developed system integrated by the measurement module based on the common path Fabry–Pérot interferometer for linear displacement and the auto-alignment module for optical axes was proposed to realize the automatic linear displacement calibration of the linear stages. The measurement performance of the developed structure was verified experimentally. With the auto-alignment module, the cosine error was reduced to 0.36 nm and the entire procedure accomplished within 75 s without the limitation of the perceived resolution of the human eye, operational experience, and the risk of misalignment and broken cable. According to the comparison of experimental results for the linear displacement, the repeatability of the proposed measurement module was less than 0.171 μm. After the compensation procedure according to the linear displacement calibration, the systematic positional deviation, repeatability, and accuracy of the linear axis could be improved to 4 μm, 1 μm, and 5 μm respectively. Hence, the calibration efficiency can be improved by 80% with the proposed compact system, which is beneficial for the linear displacement calibration of machine tools in the precision mechanical engineering industry.

Fabry–Pérot interferometer utilized for displacement measurement in a large measuring range

2010 ◽  
Vol 81 (9) ◽  
pp. 093102 ◽  
Author(s):  
Yung-Cheng Wang ◽  
Lih-Horng Shyu ◽  
Chung-Ping Chang
Keyword(s):  
Displacement Measurement ◽  
Measuring Range ◽  
Fabry Perot

Modified Fabry-Perot interferometer for displacement measurement in ultra large measuring range

2013 ◽  
Vol 84 (5) ◽  
pp. 053105 ◽  
Author(s):  
Chung-Ping Chang ◽  
Pi-Cheng Tung ◽  
Lih-Horng Shyu ◽  
Yung-Cheng Wang ◽  
Eberhard Manske
Keyword(s):  
Displacement Measurement ◽  
Measuring Range ◽  
Fabry Perot

Design and Analysis of Dual-Beam Heterodyne Interferometer

2011 ◽  
Vol 103 ◽  
pp. 177-180
Author(s):  
Ai Song Ju ◽  
Yun Bo Zhang ◽  
Wen Mei Hou
Keyword(s):  
Zeeman Effect ◽  
Optical Path ◽  
Laser Source ◽  
Nonlinearity Error ◽  
Heterodyne Interferometer ◽  
Common Path ◽  
Dual Beam ◽  
The Stability

A dual-beam heterodyne interferometer is designed in this paper. Unlike the Zeeman-effect laser, the two frequencies are generated by two acousto-optic modulators. The different frequency beams are spatial separated, but the optical path comply the principle of common path. Nonlinearity in this system is analyzed in this paper. The periodic nonlinearity error caused by non-ideal laser source is not existed in this system. The stability of this system is tested.

Detection of Hydrogen Peroxide Using Photofragmentation Laser-Induced Fluorescence

2008 ◽  
Vol 62 (1) ◽  
pp. 66-72 ◽  
Author(s):  
O. Johansson ◽  
J. Bood ◽  
M. Aldén ◽  
U. Lindblad
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Signal Strength ◽  
Measurement Procedure ◽  
Laser Induced Fluorescence ◽  
Excitation Pulse ◽  
Oh Radicals ◽  
Single Shot ◽  
First Time ◽  
Hydrogen Peroxide Vapor

Photofragmentation laser-induced fluorescence (PF-LIF) is for the first time demonstrated to be a practical diagnostic tool for detection of hydrogen peroxide. Point measurements as well as two-dimensional (2D) measurements in free-flows, with nitrogen as bath gas, are reported. The present application of the PF-LIF technique involves one laser, emitting radiation of 266 nm wavelength, to dissociate hydrogen peroxide molecules into OH radicals, and another laser, emitting at 282.25 nm, to electronically excite OH, whose laser-induced fluorescence is detected. The measurement procedure is explained in detail and a suitable time separation between photolysis and excitation pulse is proposed to be on the order of a few hundred nanoseconds. With a separation time in that regime, recorded OH excitation scans were found to be thermal and the signal was close to maximum. The PF-LIF signal strength was shown to follow the same trend as the vapor pressure corresponding to the hydrogen peroxide liquid concentration. Thus, the PF-LIF signal appeared to increase linearly with hydrogen peroxide vapor-phase concentration. For 2D single shot measurements, a conservatively estimated value of the detection limit is 30 ppm. Experiments verified that for averaged point measurements the detection limit was well below 30 ppm.

scholarly journals Comparison between Capacitive and Microstructured Optical Fiber Soil Moisture Sensors

2018 ◽  
Vol 8 (9) ◽  
pp. 1499 ◽  
Author(s):  
Aitor Lopez Aldaba ◽  
Diego Lopez-Torres ◽  
Miguel Campo-Bescós ◽  
José López ◽  
David Yerro ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Optical Fiber ◽  
Soil Conditions ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Soil Moisture Sensors ◽  
Microstructured Optical Fiber ◽  
Fabry Perot ◽  
Local Measurements ◽  
First Time

Soil moisture content has always been an important parameter to control because it is a deterministic factor for site-specific irrigation, seeding, transplanting, and compaction detection. In this work, a discrete sensor that is based on a SnO2–FP (Fabry-Pérot) cavity is presented and characterized in real soil conditions. As far as authors know, it is the first time that a microstructured optical fiber is used for real soil moisture measurements. Its performance is compared with a commercial capacitive soil moisture sensor in two different soil scenarios for two weeks. The optical sensor shows a great agreement with capacitive sensor’s response and gravimetric measurements, as well as a fast and reversible response; moreover, the interrogation technique allows for several sensors to be potentially multiplexed, which offers the possibility of local measurements instead of volumetric: it constitutes a great tool for real soil moisture monitoring.

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