Analysis of Substrates for Single Emitter Laser Diodes

2003 ◽  
Vol 125 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Tapani M. Alander ◽  
Pekka A. Heino ◽  
Eero O. Ristolainen
Keyword(s):  
Thermal Performance ◽  
System Integration ◽  
Large Scale ◽  
Mechanical Performance ◽  
Laser Diodes ◽  
Substrate Material ◽  
Ceramic Substrates ◽  
Large Scale Integration ◽  
Semiconductor Laser Diodes ◽  
Scale Integration

Electrically conductive substrates (i.e., metals) are often used in the mounting of semiconductor laser diodes. While metals offer a good electrical and thermal performance, they restrict the system integration due to lack of signal routing capability. Since the implementations utilizing laser diodes have become more common, the integration level has also become an important factor in these products. Mounting of lasers on insulative substrates is the key to large-scale integration. Organic boards form the de facto standard of insulative substrates; however, their use with lasers is impossible due to low thermal conductivity. Ceramics, however, offer nearly the same thermal performance as metals but as electrically insulative materials also provide the foundation for high integration levels. In this study the effects of three different ceramic substrates on the stresses within diode lasers was evaluated. Finite element method was used to calculate the mounting induced straining and the thermal performance of the substrate. The same procedure was employed to examine the optimum metallization thickness for the ceramic substrates. The results present how greatly the substrate material can affect the very delicate laser diode. The ceramic substrates, though having nearly the same properties, exhibited clearly distinctive behavior and a great difference in thermal and mechanical performance.

scholarly journals Large Photovoltaic Power Plants Integration: A Review of Challenges and Solutions

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3798 ◽  
Author(s):  
Mansouri ◽  
Lashab ◽  
Sera ◽  
Guerrero ◽  
Cherif
Keyword(s):  
System Integration ◽  
Power Plants ◽  
Large Scale ◽  
System Stability ◽  
Pv System ◽  
Pv Systems ◽  
Large Scale Integration ◽  
Voltage Limit ◽  
The Stability ◽  
Scale Integration

Renewable energy systems (RESs), such as photovoltaic (PV) systems, are providing increasingly larger shares of power generation. PV systems are the fastest growing generation technology today with almost ~30% increase since 2015 reaching 509.3 GWp worldwide capacity by the end of 2018 and predicted to reach 1000 GWp by 2022. Due to the fluctuating and intermittent nature of PV systems, their large-scale integration into the grid poses momentous challenges. This paper provides a review of the technical challenges, such as frequency disturbances and voltage limit violation, related to the stability issues due to the large-scale and intensive PV system penetration into the power network. Possible solutions that mitigate the effect of large-scale PV system integration on the grid are also reviewed. Finally, power system stability when faults occur are outlined as well as their respective achievable solutions.

scholarly journals Hydrogen-Assisted Sputtering Growth of TiN on Ceramic Substrates

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 255 ◽  
Author(s):  
Jaewon Choi ◽  
Wonjin Jeon ◽  
Dongjin Kang ◽  
Doowon Kang ◽  
Jungyol Jo
Keyword(s):  
Large Scale ◽  
Hydrogen Gas ◽  
Main Hypothesis ◽  
Ceramic Substrates ◽  
Tin Film ◽  
Discrete Device ◽  
Trapped Gases ◽  
Large Scale Integration ◽  
Scale Integration

Titanium nitride (TiN) has mechanical and electrical characteristics applicable for very large scale integration (VLSI) and discrete electronic devices. This study assessed the effect of hydrogen on sputtering growth of TiN on ceramic substrates. Although ceramic substrate is used in discrete device applications due to its insulating property, ceramic is also porous and contains oxygen and water vapor gases, which can be incorporated into TiN films during growth. In addition, discrete devices are usually packaged in glass sealing at 700 °C, and reaction with the trapped gases can significantly degrade the quality of the TiN film. In order to evaluate ways to minimize the effects of these gases on TiN, hydrogen gas was introduced during sputtering growth. The main hypothesis was that the hydrogen gas would react with oxygen to lower the oxygen density in the vacuum chamber, which would suppress the effects of the trapped gases in the ceramic and ultimately improve the quality of the TiN film. Improvements in TiN quality were confirmed by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and resistance measurements. During the glass-sealing process, N2-purging at 400 °C was effective at keeping the TiN in a low resistance state. These results show that introducing hydrogen gas during sputtering growth could solve the problems caused by ceramic substrates.

Plant hormones, plant growth regulators

2014 ◽  
Vol 155 (26) ◽  
pp. 1011-1018 ◽  
Author(s):  
György Végvári ◽  
Edina Vidéki
Keyword(s):  
Nervous System ◽  
Growth And Development ◽  
Large Scale ◽  
Essential Role ◽  
Higher Plants ◽  
Structure And Function ◽  
Wide Sense ◽  
Large Scale Integration ◽  
Scale Integration ◽  
And Function

Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy beween organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants’ life. Orv. Hetil., 2014, 155(26), 1011–1018.

Behavior Models of Voltage Differencing Inverting Buffered Amplifier and Applications in Circuit Analysis

2019 ◽  
Vol 12 (4) ◽  
pp. 298-303
Author(s):  
YongAn LI
Keyword(s):  
Large Scale ◽  
Vlsi Design ◽  
Circuit Analysis ◽  
Second Order ◽  
Very Large Scale Integration ◽  
Behavioral Models ◽  
Order Filter ◽  
Large Scale Integration ◽  
Scale Integration ◽  
Behavior Models

Background: The symbolic nodal analysis acts as a pivotal part of the very large scale integration (VLSI) design. Methods: In this work, based on the terminal relations for the pathological elements and the voltage differencing inverting buffered amplifier (VDIBA), twelve alternative pathological models for the VDIBA are presented. Moreover, the proposed models are applied to the VDIBA-based second-order filter and oscillator so as to simplify the circuit analysis. Results: The result shows that the behavioral models for the VDIBA are systematic, effective and powerful in the symbolic nodal circuit analysis.</P>

Sign in / Sign up

Export Citation Format

Share Document