Noise reduction of violet laser diodes by selection of feedback light polarization

2006 ◽  
Author(s):  
Hironobu Konishi ◽  
Hideyuki Yashiro ◽  
Katsuya Takegami ◽  
Wakao Sasaki ◽  
Atsushi Ikeda ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Laser Diodes ◽  
Light Polarization ◽  
Selection Of ◽  
Feedback Light

scholarly journals Analysis of Void Formation Mechanism in the Vacuum Reflow Soldering Process of Semiconductor Laser Diode

2021 ◽  
Author(s):  
Peidong Xu ◽  
Bin Wang ◽  
Yong Wang ◽  
Xiantao Wang
Keyword(s):  
Semiconductor Laser ◽  
Formation Mechanism ◽  
Laser Diodes ◽  
Void Formation ◽  
Reflow Soldering ◽  
Soldering Process ◽  
Semiconductor Laser Diode ◽  
Soldering Technology ◽  
Semiconductor Laser Diodes ◽  
Selection Of

In this paper, the vacuum reflow soldering technology for semiconductor laser chips in optoelectronic devices was studied and analyzed in a systematic manner. Through the study on the key elements in the reflow soldering process, such as the selection of solders, <a>chamber</a> vacuum, flux, and the pressure applied by the fixture on the chip, this paper focused on exploring the formation mechanism of voids in the solder layer when the device was resoldered. Also, the change in the movement of gas bubbles in the voids with changing reflow oven chamber conditions and its underlying law were analyzed, by preparing 200 C-package semiconductor laser diodes and verifying the reliability and stability of the theoretical analysis through inspection and test aging. which could provide a theoretical basis for the use of the vacuum reflow soldering technology to reduce the void rate in the soldering process of devices.

Attenuating Railway Track Vibration by Rail Absorber for Noise Reduction

2008 ◽  
Vol 39 (9) ◽  
pp. 14-23 ◽  
Author(s):  
T. X. Wu
Keyword(s):  
Noise Reduction ◽  
Decay Rate ◽  
Vibration Reduction ◽  
Railway Track ◽  
Low Loss ◽  
Active Mass ◽  
Track Dynamics ◽  
Damping Material ◽  
Piecewise Continuous ◽  
Selection Of

A promising means to increase the decay rate of vibration along the rail is using a rail absorber for noise reduction. Compound track models with the tuned rail absorber are used for investigation of the performance of the absorber on vibration reduction. Through analysis of the track dynamics with the rail absorber some guidelines are given on selection of the types and parameters for the rail absorber. It is found that a large active mass used in the absorber is beneficial to increase the decay rate of rail vibration. The effectiveness of the piecewise continuous absorber is moderate compared with the discrete absorber installed in the middle of sleeper span or at a sleeper. The most effective installation position for the discrete absorber is in the middle of sleeper span. Over high or over low loss factor of the damping material used in the absorber may degrade the vibration reduction performance.

scholarly journals Growing epitaxial layers of InP/InGaAsP heterostructures on the profiled InP surfaces by liquid-phase epitaxy

2021 ◽  
Vol 23 (2) ◽  
pp. 204-211
Author(s):  
Mikhail G. Vasil’ev ◽  
Anton M. Vasil’ev ◽  
Alexander D. Izotov ◽  
Yuriy O. Kostin ◽  
Alexey A. Shelyakin
Keyword(s):  
Liquid Phase ◽  
Indium Phosphide ◽  
Dissolution Rate ◽  
Liquid Phase Epitaxy ◽  
Chemical Etching ◽  
Laser Diodes ◽  
Epitaxial Layers ◽  
The Difference ◽  
Inp Substrates ◽  
Selection Of

The effect of various planes was studied when growing epitaxial layers by liquid-phase epitaxy (LPE) on the profiled InP substrates. The studies allowed obtaining buried heterostructures in the InP/InGaAsP system and creating highly efficient laser diodes and image sensors.It was found that protruding mesa strips or in-depth mesa strips in the form of channels formed by the {111}А, {111}B, {110}, {112}A, or {221}A family of planes can be obtained with the corresponding selection of an etching agent, strip orientation, and a method of obtaining a masking coating. It was noted that in the case of the polarity of axes being in the direction of <111>, the cut of mesa strips was conducted along the most densely packaged planes. This cut led to the difference in rates of both chemical etching and epitaxial burying of profiled surfaces.The cut was made along the planes at a low dissolution rate {111}A for a sphalerite lattice, to which the studied material, indium phosphide, belongs. Analysis of planes {110} and {Ī10} showed that the location of the most densely packaged planes {111}A and {111}B relative to them is different.

scholarly journals Analysis of Void Formation Mechanism in the Vacuum Reflow Soldering Process of Semiconductor Laser Diode

2021 ◽  
Author(s):  
Peidong Xu ◽  
Bin Wang ◽  
Yong Wang ◽  
Xiantao Wang
Keyword(s):  
Semiconductor Laser ◽  
Formation Mechanism ◽  
Laser Diodes ◽  
Void Formation ◽  
Reflow Soldering ◽  
Soldering Process ◽  
Semiconductor Laser Diode ◽  
Soldering Technology ◽  
Semiconductor Laser Diodes ◽  
Selection Of

In this paper, the vacuum reflow soldering technology for semiconductor laser chips in optoelectronic devices was studied and analyzed in a systematic manner. Through the study on the key elements in the reflow soldering process, such as the selection of solders, <a>chamber</a> vacuum, flux, and the pressure applied by the fixture on the chip, this paper focused on exploring the formation mechanism of voids in the solder layer when the device was resoldered. Also, the change in the movement of gas bubbles in the voids with changing reflow oven chamber conditions and its underlying law were analyzed, by preparing 200 C-package semiconductor laser diodes and verifying the reliability and stability of the theoretical analysis through inspection and test aging. which could provide a theoretical basis for the use of the vacuum reflow soldering technology to reduce the void rate in the soldering process of devices.

scholarly journals Study on the Application of 220/20kV SF6 Gas Transformer

2020 ◽  
Vol 2 (1) ◽  
pp. 5
Author(s):  
Jun Zhou ◽  
Weidong Chen ◽  
Haoxi Tu ◽  
Lianfeng Wang ◽  
Hongmei Ni
Keyword(s):  
Noise Reduction ◽  
Fire Protection ◽  
Structural Characteristics ◽  
Power Grid ◽  
Rapid Development ◽  
Land Resources ◽  
Selection Of

<p>With the rapid development of Shenzhen's economy, the land resources in Shenzhen are more and more scarce, and the location of substation is more and more difficult. In order to solve the contradiction between the land resources shortage and the development of power grid, the new mode of substation construction of "embedded attached substation" came into being. Because of the particularity of the embedded attached substation, the fire protection requires that the equipment of this kind of substation should be oil-free, making it difficult to select the appropriate 220/20kV transformer. Therefore, this paper studies a new 220/20kV SF6 gas transformer for the above problems, combined with its structural characteristics, aspects including fire protection, ventilation and noise reduction are described to provide reference for transformer selection of this type of substation.</p>

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