Profile and groove‐depth control in GaAs diffraction gratings fabricated by preferential chemical etching in H2SO4‐H2O2‐H2O system

1976 ◽  
Vol 28 (1) ◽  
pp. 44-46 ◽  
Author(s):  
Won‐Tien Tsang ◽  
Shyh Wang
Keyword(s):  
Chemical Etching ◽  
Diffraction Gratings ◽  
Groove Depth ◽  
Depth Control

Photon excitation of surface plasmons in diffraction gratings: Effect of groove depth and spacing

1976 ◽  
Vol 13 (6) ◽  
pp. 2372-2376 ◽  
Author(s):  
C. E. Wheeler ◽  
E. T. Arakawa ◽  
R. H. Ritchie
Keyword(s):  
Surface Plasmons ◽  
Diffraction Gratings ◽  
Groove Depth ◽  
Photon Excitation

Finely control groove-depth variations of large-area diffraction gratings

2015 ◽  
Author(s):  
Lixiang Wu ◽  
Keqiang Qiu ◽  
Xiaolong Jiang ◽  
Yanchang Zheng ◽  
Xiangdong Xu ◽  
...  
Keyword(s):  
Diffraction Gratings ◽  
Groove Depth ◽  
Large Area

Control of Machining Profiles Based on Material Removal Capabilities in Cylindrical Blasting

2016 ◽  
Vol 1136 ◽  
pp. 125-130
Author(s):  
Masashi Harada ◽  
Kazuhito Ohashi ◽  
Taketo Fukushima ◽  
Shinya Tsukamoto
Keyword(s):  
Chemical Etching ◽  
Material Removal ◽  
Fluid Dynamic ◽  
Dynamic Pressure ◽  
Electrochemical Machining ◽  
Disk Drive ◽  
Groove Depth ◽  
High Accuracy ◽  
Processing Unit ◽  
Central Processing

Fluid dynamic bearings, which have an advantage in high-accuracy revolutions, are employed for spindle motors of hard disk drive, cooling fans for central processing unit, spindles of machine tool, etc. Micro herring-bone grooves are manufactured on cylindrical surface of the shafts in the bearing units, and they generate dynamic pressure during spins. Although the depth of the herring-bone grooves is generally constant, the shafts of which groove depth decreases from the ends of the groove array to its center improve the performance of bearing. The micro grooves are mainly manufactured by chemical etching, electrochemical machining, cutting and form rolling. However, the chemical etching and the electrochemical machining are difficult to control 3D machining profiles with high accuracy. The cutting and the form rolling have problems in tool lives and manufacturing costs. On the other hand, blasting is expected as one of micro fabrication methods. Therefore, we focused on blasting, and have investigated its material removal capabilities by fundamental tests. The purpose of this study is to control machining profiles in cylindrical blasting. The machining profiles of cylindrical workpieces in blasting were simulated based on the material removal capabilities obtained by the fundamental blasting tests. Then, the simulated profiles agreed well with the experimental ones by blasting under the same experimental condition.

The Wear Analysis of Chisel-Edge Ruling Tool for Diffraction Gratings

2013 ◽  
Vol 772 ◽  
pp. 389-393
Author(s):  
Jiri Galantu
Keyword(s):  
Tool Wear ◽  
Diffraction Efficiency ◽  
Diffraction Gratings ◽  
Groove Depth ◽  
The Other ◽  
Wear Analysis ◽  
Test Study

The wear analysis of chisel-edge ruling tool for diffraction gratings is very complex because of following two reasons that one is the wear distribution on edge after grating ruling is too minute so that hard to find and measured by conventional equipment like microscope, and the other is the effect of wear on the groove depth, pitch, ridge, blaze angle, non-blaze angle, groove bottom angle and diffraction efficiency of gratings. In order to determine what extent of wear is can be ignored, this paper had go on brief approximate test study on wear analysis of chisel-edge ruling tool for diffraction gratings which ruling echelle gratings groove density of 79 gr/mm, and analyzed the variation of groove depth, pitch, ridge, blaze angle, non-blaze angle, groove bottom angle and diffraction efficiency along with ruling distance, and found the microscale tool wear on chisel-edge ruling tool, finally determined this extent of tool wear cannot effect ruling echelle gratings groove density of 79 gr/mm .

The observation of defects on (100) CdTe surfaces by chemical etching

1992 ◽  
Vol 50 (2) ◽  
pp. 1424-1425
Author(s):  
M.E. Lee
Keyword(s):  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Chemical Etching ◽  
Crystalline Perfection ◽  
Crystalline Defects ◽  
High Incidence ◽  
Crystallographic Defects ◽  
Cdznte Substrates ◽  
Device Technology

The crystalline perfection of bulk CdTe substrates plays an important role in their use in infrared device technology. The application of chemical etchants to determine crystal polarity or the density and distribution of crystallographic defects in (100) CdTe is not well understood. The lack of data on (100) CdTe surfaces is a result of the apparent difficulty in growing (100) CdTe single crystal substrates which is caused by a high incidence of twinning. Many etchants have been reported to predict polarity on one or both (111) CdTe planes but are considered to be unsuitable as defect etchants. An etchant reported recently has been considered to be a true defect etchant for CdTe, MCT and CdZnTe substrates. This etchant has been reported to reveal crystalline defects such as dislocations, grain boundaries and inclusions in (110) and (111) CdTe. In this study the effect of this new etchant on (100) CdTe surfaces is investigated.The single crystals used in this study were (100) CdTe as-cut slices (1mm thickness) from Bridgman-grown ingots.

Adaptive depth control algorithm for sound tracing

2018 ◽  
Vol 24 (5) ◽  
pp. 21-30
Author(s):  
Eun Jae Kim ◽  
Woonam Chung ◽  
Woochan Park ◽  
Yun Juwon ◽  
Youngsik Kim
Keyword(s):  
Control Algorithm ◽  
Depth Control
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