Simultaneous thickness variation and surface profiling of glass plates using Fizeau interferometer with elimination of offset phase error

2021 ◽  
Vol 480 ◽  
pp. 126500
Author(s):  
Wonjun Bae ◽  
Yangjin Kim ◽  
Young Hoon Moon ◽  
Kenichi Hibino ◽  
Naohiko Sugita ◽  
...  
Keyword(s):  
Phase Error ◽  
Thickness Variation ◽  
Fizeau Interferometer ◽  
Surface Profiling ◽  
Glass Plates

Phase error calculation in a Fizeau interferometer by Fourier expansion of the intensity profile

1996 ◽  
Vol 35 (1) ◽  
pp. 61 ◽  
Author(s):  
B. V. Dorrío ◽  
J. Blanco-García ◽  
C. López ◽  
A. F. Doval ◽  
R. Soto ◽  
...  
Keyword(s):  
Fourier Expansion ◽  
Phase Error ◽  
Intensity Profile ◽  
Fizeau Interferometer ◽  
Error Calculation

scholarly journals Algorithm for Surfaces Profiles and Thickness Variation Measurement of a Transparent Plate Using a Fizeau Interferometer with Wavelength Tuning

2019 ◽  
Vol 9 (11) ◽  
pp. 2349 ◽  
Author(s):  
Tao Sun ◽  
Weiwei Zheng ◽  
Yingjie Yu ◽  
Ketao Yan ◽  
Anand Asundi ◽  
...  
Keyword(s):  
Rear Surface ◽  
Surface Profile ◽  
Measuring Method ◽  
Processing Technique ◽  
Repeated Measurements ◽  
Thickness Variation ◽  
Fizeau Interferometer ◽  
Transparent Plate ◽  
Surface Profiles ◽  
Step Algorithm

An interferogram obtained from a transparent plate contains information on the profiles of both surfaces and on the thickness variation. The present work is devoted to the processing of interferograms of this type. The processing technique is based on a 36-step algorithm developed by the authors for characterization of transparent plates having approximately equal reflections from both sides. The algorithm utilizes weighted multi-step phase shifting that enables one not only separately to extract the front and rear surface profiles together with the thickness variation of the tested plate but also to suppress the coupling errors between the higher harmonics and phase-shift deviation. The proposed measuring method was studied on a wavelength tunable Fizeau interferometer. The tested sample had an optical thickness and surface profile deviations equal to 0.51 µm, 1.38 µm and 0.89 µm, respectively. According to the results obtained using 10 repeated measurements, the root mean square (RMS) errors for determining both surface profiles did not exceed 1.5 nm. Experimental results show that the setup and presented 36-step algorithm are suitable for the measurement of a transparent plate of arbitrary thickness.

Experiments with a scanning tunneling microscope (STM) mounted in a scanning electron microscope (SEM)

1986 ◽  
Vol 44 ◽  
pp. 636-639
Author(s):  
Oliver C. Wells ◽  
Mark E. Welland
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Stability ◽  
Tunneling Current ◽  
Feedback System ◽  
Scanning Tunneling ◽  
Surface Profiling ◽  
Close Proximity ◽  
Metal Tip ◽  
Scanning Electron

Scanning tunneling microscopes (STM) exist in two versions. In both of these, a pointed metal tip is scanned in close proximity to the specimen surface by means of three piezos. The distance of the tip from the sample is controlled by a feedback system to give a constant tunneling current between the tip and the sample. In the low-end STM, the system has a mechanical stability and a noise level to give a vertical resolution of between 0.1 nm and 1.0 nm. The atomic resolution STM can show individual atoms on the surface of the specimen.A low-end STM has been put into the specimen chamber of a scanning electron microscope (SEM). The first objective was to investigate technological problems such as surface profiling. The second objective was for exploratory studies. This second objective has already been achieved by showing that the STM can be used to study trapping sites in SiO2.

Some Quantification Problems in Parallel EELS Images

1990 ◽  
Vol 48 (2) ◽  
pp. 36-37
Author(s):  
G. Botton ◽  
G. L’Espérance ◽  
M.D. Ball ◽  
C.E. Gallerneault
Keyword(s):  
Electron Microscope ◽  
Imaging System ◽  
Signal To Noise Ratio ◽  
Scanning Transmission Electron Microscope ◽  
Acquisition Time ◽  
Thickness Variation ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Scanning Transmission ◽  
Present Distribution

The recently developed parallel electron energy loss spectrometers (PEELS) have led to a significant reduction in spectrum acquisition time making EELS more useful in many applications in material science. Dwell times as short as 50 msec per spectrum with a PEELS coupled to a scanning transmission electron microscope (STEM), can make quantitative EEL images accessible. These images would present distribution of elements with the high spatial resolution inherent to EELS. The aim of this paper is to briefly investigate the effect of acquisition time per pixel on the signal to noise ratio (SNR), the effect of thickness variation and crystallography and finally the energy stability of spectra when acquired in the scanning mode during long periods of time.The configuration of the imaging system is the following: a Gatan PEELS is coupled to a CM30 (TEM/STEM) electron microscope, the control of the spectrometer and microscope is performed through a LINK AN10-85S MCA which is interfaced to a IBM RT 125 (running under AIX) via a DR11W line.

Formulation and Evaluation of Fast Disintigrating Meloxicam Tablets and Its Comparison with Marketed Product

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Suresh Kulkarni ◽  
Ranjit P. ◽  
Nikunj Patel ◽  
Someshwara B. ◽  
Ramesh B. ◽  
...  
Keyword(s):  
Water Absorption ◽  
In Vitro Dissolution ◽  
Thickness Variation ◽  
Wet Granulation ◽  
Disintegration Time ◽  
Absorption Ratio ◽  
Wetting Time ◽  
Fast Disintegrating Tablets ◽  
Cox 1

The present investigation deals with the formulation of fast disintegrating tablets of Meloxicam that disintegrate in the oral cavity upon contact with saliva and there by improve therapeutic efficacy. Meloxicam is a newer selective COX-1 inhibitor. The tablets were prepared by wet granulation procedure. The influence of superdisintegrants, crosspovidone, croscaremellose sodium on disintegration time, wetting time and water absorption ratio were studied. Tablets were evaluated for weight and thickness variation, disintegration time, drug content, in vitro dissolution, wetting time and water absorption ratio. The in vitro disintegration time of the best fast disintegrating tablets was found to be 18 sec. Tablets containing crospovidone exhibit quick disintegration time than tablets containing croscaremellose sodium. The fast disintegrating tablets of Meloxicam with shorter disintegration time, acceptable taste and sufficient hardness could be prepared using crospovidone and other excipients at optimum concentration.

RF Phase Error Built-In-Self-Test for A GSM SOC

2008 ◽  
Vol 1 (4) ◽  
pp. 39-44
Author(s):  
Dallas Webster ◽  
Loi Phan ◽  
Oren Eliezer ◽  
Rick Hudgens ◽  
Donald Lie
Keyword(s):  
Phase Error ◽  
Self Test ◽  
Built In Self Test

Формирование изображений электрических сигналов преобразователя магнитного поля при гистерезисной интерференции для контроля металлов в импульсных магнитных полях

2020 ◽  
pp. 38-45
Author(s):  
В.В. Павлюченко ◽  
Е.С. Дорошевич
Keyword(s):  
Magnetic Field ◽  
Aluminum Plate ◽  
Thickness Variation ◽  
Magnetic Carrier ◽  
Electric Voltage ◽  
Total Strength ◽  
Magnetic Field Transducer ◽  
The Given ◽  
The Magnetic Field

Based on the developed methods of hysteresis interference, the calculated dependences U(x) of the electric voltage taken from the magnetic field transducer on the x coordinate were obtained. A magnetic carrier with an arctangent characteristic was exposed to a series of bipolar pulses of the magnetic field of a linear inductor of one, two, three, four, five and fifteen pulses. An algorithm is presented for the sequence of changes in the magnitude of the total strength of the magnetic field pulses on the surface of an aluminum plate, which provides the same amplitude of hysteresis oscillations of the electric voltage and makes it possible to obtain a linear difference dependence U(x) for wedge-shaped and flat aluminum samples. The results obtained make it possible to increase the accuracy and efficiency of control of the thickness of the object and its thickness variation in the given directions, as well as the defects of the object.

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