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.

Test-Retest-Reliability of Computer-Based Metamorphopsia Measurement in Macular Diseases

2020 ◽  
Author(s):  
Daniela Claessens ◽  
Alexander K. Schuster ◽  
Ronald V. Krüger ◽  
Marian Liegl ◽  
Laila Singh ◽  
...  
Keyword(s):  
Macular Edema ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Measuring Method ◽  
Repeated Measurements ◽  
Retest Reliability ◽  
Macular Diseases ◽  
Computer Based ◽  
Test Retest Reliability

AbstractIn this study, the test-retest-reliability as one aspect of reliability of metamorphopsia measurements using a computer-based measuring method was determined in patients with macular diseases. Metamorphopsia amplitude, position, and area were quantified using AMD – A Metamorphopsia Detector software (app4eyes GmbH & Co. KG, Germany) in patients with diabetic, myopic, or uveitic macular edema, intermediate or neovascular age-associated macular degeneration, epiretinal membrane, vitelliform maculopathy, Irvine-Gass syndrome, or macular edema due to venous retinal occlusion. The intraclass correlation coefficient (ICC) was calculated in order to determine the repeatability of two repeated measurements and was used as an indicator of the reliability of the measurements. In this study, metamorphopsia measurements were conducted on 36 eyes with macular diseases. Metamorphopsia measurements made using AMD – A Metamorphopsia Detector software were highly reliable and repeatable in patients with maculopathies. The intraclass correlation coefficient of all indices was excellent (0.95 – 0.97). For diseases of the vitreoretinal interface or macular diseases with intra- or subretinal edema, this metamorphopsia measurement represents a supplement for visual function testing in the clinic, as well as in clinical studies.

scholarly journals A Simple Model to Predict Machined Depth and Surface Profile for Picosecond Laser Surface Texturing

2018 ◽  
Vol 8 (11) ◽  
pp. 2111 ◽  
Author(s):  
Jieyu Xian ◽  
Xingsheng Wang ◽  
Xiuqing Fu ◽  
Zhengwei Zhang ◽  
Lu Liu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Surface Texturing ◽  
Surface Profile ◽  
Picosecond Laser ◽  
Scanning Speed ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Micro Channels ◽  
Surface Profiles ◽  
Simulation Parameters

A simple mathematical model was developed to predict the machined depth and surface profile in laser surface texturing of micro-channels using a picosecond laser. Fabrication of micro-craters with pulse trains of different numbers was initially performed. Two baseline values from the created micro-craters were used to calculate the estimated simulation parameters. Thereafter, the depths and profiles with various scanning speeds or adjacent intervals were simulated using the developed model and calculated parameters. Corresponding experiments were conducted to validate the developed mathematical model. An excellent agreement was obtained for the predicted and experimental depths and surface profiles. The machined depth decreased with the increase of scanning speed or adjacent interval.

Geometrical consideration for mechanical contact between rolling circle and surface roughness as an improvement to the surface profile

2021 ◽  
Vol 15 (1) ◽  
pp. 7846-7859
Author(s):  
Tsuyoshi Shimizu ◽  
Yasutake Hramiishi ◽  
Takaaki Ishii ◽  
Yuzairi Abdul Rahim ◽  
Mohd Fadzil Ali Ahmad ◽  
...  
Keyword(s):  
Contact Point ◽  
Surface Profile ◽  
Displacement Sensor ◽  
Nose Radius ◽  
Rolling Circle ◽  
Actual Surface ◽  
Contact Type ◽  
Measurement Surface ◽  
Surface Profiles ◽  
Tip Radius

This paper describes measurement methods of surface profiles that improve contact-type displacement sensor outputs by focusing on the contact point between the sphere tip of the sensor and the rough surface. We examined the geometry of a surface profile model and compared measurements using various methods with the measurement using a roughness meter. The spherical tip of the contact type displacement sensor touches the measurement surface and detects the displacement. The sphere tip radius of a typical contact-type displacement sensor ranges from 1–3 mm, causing the roughness curve to be “filtered” by the radius of the sphere.  Three methods for estimating the valley portion of the surface profile are evaluated in this study: a) linear approximation of the concave portion of the surface profile, b) function approximation of the concave portion, and c) using the known nose radius of the machining tool. The following sphere tip radii were used to measure actual surface profiles: 0.25 mm, 0.5 mm, 1.0 mm and 1.5 mm. Given the conditions of the experimental model, we found that surface profiles with a roughness that approximates a predictable curve can be measured with a high degree of accuracy.

scholarly journals How surface stress transforms surface profiles and adhesion of rough elastic bodies

2020 ◽  
Vol 476 (2243) ◽  
pp. 20200477
Author(s):  
Chung-Yuen Hui ◽  
Zezhou Liu ◽  
Nicolas Bain ◽  
Anand Jagota ◽  
Eric R. Dufresne ◽  
...  
Keyword(s):  
Surface Stress ◽  
Periodic Structures ◽  
Surface Profile ◽  
Initial Surface ◽  
One Dimensional ◽  
Patterned Substrate ◽  
Soft Solids ◽  
Elastic Bodies ◽  
Surface Profiles ◽  
Qualitative Changes

The surface of soft solids carries a surface stress that tends to flatten surface profiles. For example, surface features on a soft solid, fabricated by moulding against a stiff-patterned substrate, tend to flatten upon removal from the mould. In this work, we derive a transfer function in an explicit form that, given any initial surface profile, shows how to compute the shape of the corresponding flattened profile. We provide analytical results for several applications including flattening of one-dimensional and two-dimensional periodic structures, qualitative changes to the surface roughness spectrum, and how that strongly influences adhesion.

Experimental and Theoretical Studies of the Fractal Scaling Parameter and the Lateral Scale Dependence of the Asperity Interference

2007 ◽  
Author(s):  
Shao Wang ◽  
Yi Hui Leong
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Numerical Scheme ◽  
Surface Profile ◽  
Density Data ◽  
Fractal Scaling ◽  
Scaling Parameter ◽  
Power Spectral ◽  
Surface Profiles ◽  
The Difference

The fractal scaling parameter was released in a recent study from its artificially assigned constant value to become a measurable parameter for simulated surface profiles. In the present study, this concept was extended to develop schemes for determining the fractal scaling parameter from experimental power spectral density data. The difference in the trends of peaks has been observed between experimental power spectral density data and those of the Weierstrass-Mandelbrot function. A modified W-M function was proposed based on a peak splitting behavior of the power spectrum. To verify a relationship between the interference and lateral length scale for asperities, which is commonly assumed in fractal modeling, a numerical scheme was developed to truncate measured surface profiles for finding asperity interferences for microcontacts of various sizes. This relationship was confirmed by the favorable results from a comparison of the power values obtained from truncation of a surface profile to those obtained by using the fast Fourier transform. A numerical scheme was developed to generate random power spectral density curves and fractal surface profiles for given values of the fractal scaling parameter.

Ultra-Precision Shaping and Ultra-Smooth Polishing Investigation of High-Purity Quartz Glass in Nanoparticle Colloid Jet Machining

2012 ◽  
Vol 426 ◽  
pp. 396-399 ◽  
Author(s):  
Xiao Zong Song ◽  
Yong Zhang ◽  
Fei Hu Zhang
Keyword(s):  
Quartz Glass ◽  
High Purity ◽  
Glass Surface ◽  
Morphological Characteristics ◽  
Surface Profile ◽  
Processing Technique ◽  
Surface Shape ◽  
Before And After ◽  
Ultra Precision ◽  
Nanoparticle Colloid

In this paper, ultra-precision shaping and ultra-smooth polishing investigations have been done upon a high-purity quartz glass substrate with an aspheric surface in nanoparticle colloid jet machining, which is an ultra smooth surface processing technique utilizing surface chemical reaction between work surface atoms and nanoparticles to remove the uppermost surface atoms. The shaping and polishing characters of high-purity quartz glass in nanoparticle colloid jet machining has been researched. The surface profile of the high-purity quartz glass workpiece before and after shaping has been measured by surface profilometer. And the surface microscopic morphological characteristics of high-purity quartz glass surface polished by nanoparticle colloid jet machining have been observed by atomic force microscopy (AFM). The measurement results indicate that nanoparticle colloid jet machining has good shaping ability for surface shape correction in ultra-precision machining. And the AFM observation results show that the roughness of the high-purity quartz glass surface has been reduced from 1.919 nm RMS to 0.784 nm RMS by nanoparticle colloid jet machining.

Analysis of Handling Stresses in Thin Solar Silicon Wafers Generated by a Rigid Vacuum Gripper

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Hao Wu ◽  
Shreyes N. Melkote
Keyword(s):  
Stress Distribution ◽  
Dominant Role ◽  
High Stress ◽  
Surface Profile ◽  
Silicon Wafers ◽  
Wafer Surface ◽  
Initial Surface ◽  
Fe Modeling ◽  
Solar Silicon ◽  
Surface Profiles

Breakage of thin solar silicon wafers during handling and transport depends on the stresses imposed on the wafer by the handling/transport device. In this paper, the stresses generated in solar silicon wafers by a rigid vacuum gripper are analyzed via a combination of experiments and numerical modeling. Specifically, stresses produced in monocrystalline (Cz) and multicrystalline (Cast) silicon wafers of different thicknesses when handled by a vacuum gripper are analyzed using the finite element (FE) method. With the measured surface profiles of the wafer and the gripper as input, the handling process is simulated using FE modeling and the stress distribution obtained. The FE modeling results are validated by experimental data of wafer surface profile during handling. The results show that while the vacuum level does not have significant impact on the stress distribution, the initial surface profiles of the thin wafer and gripper play a dominant role in producing regions of high stress in the wafer.

Surface Profile Analysis in Milling with Structured Tool

2019 ◽  
Vol 13 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Fumihiro Uchiyama ◽  
Akihiko Tsuboi ◽  
Takashi Matsumura ◽  
◽  
◽  
...  
Keyword(s):  
Profile Analysis ◽  
Surface Profile ◽  
Polycrystalline Diamond ◽  
Cutting Parameters ◽  
Processing Parameters ◽  
Micro Scale ◽  
Surface Finishes ◽  
Optimum Cutting ◽  
End Mills ◽  
Surface Profiles

Novel end mills with micro-scale structures have recently been developed to promote cutting performances with cutting forces, chip controls, and tool wears. However, the surface profiles are formed corresponding to the structures on the tool edges. The surface finishes, therefore, are worse than those of cuttings with straight edges of the end mills. This paper discusses surface profiles in milling with the structured tool and the cutter axis inclination. An analytical model is presented to simulate the surface profiles for the tool edge shape, the cutting parameters and the cutter axis inclination. Because the surface profiles are controlled in the simulation, the optimum cutting parameters are determined to reduce the surface roughness. Micro-scale nicks were fabricated on polycrystalline diamond edges with a laser machine tool. The sizes and pitches of the nicks were controlled by the laser processing parameters. The cutting tests were conducted to measure the surface profiles. The presented surface profile model was validated by comparing the simulated and the measured surface roughnesses. The surface finish can be improved in milling with the cutter axis inclination in the optimum cutting parameters.

Sign in / Sign up

Export Citation Format

Share Document