IR‐Radiation
Sources &
ApplicationsPatrick Pues
Content
1. What is IR‐Radiation 2. Sources of IR‐Radiation
1. Thermal radiators2. Others
3. Detection of IR‐Radiation4. Applications of IR‐Radiation5. Summary
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What is IR‐Radiation
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http://www.eyelighting.com/_CE/pagecontent/Images/Lamp%20Technology%20Education/quality%20of%20a%20light%20source.jpg
History
• First discovered by Wilhelm Herschel (1800)• He tried to measure the temperature of colors• Highest temperature behind the red visible light
• Kirchhoff's law of thermal radiation (1859)
• Plancks Law (1901)
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Thermal radiators
• The Sun
• Nernst glower
• The Globar
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The Sun
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https://en.wikipedia.org/wiki/Sunlight#/media/File:Solar_spectrum_en.svg
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Nernst Glower
• Cylinder with 1 to 2 mm diameter and a length of 3 cm
• Mixture of ZrO2 and Y2O3 with additions of CeO2 and ThO2
• Temperature from 1200 to 2000 K
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Nernst Glower
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• External heater is necessary
• Mechanical sensitivity
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https://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Nernst_lamp.jpg/220px-Nernst_lamp.jpg
Globar
• Cylinder with 5 mm in diameter and 5 cm length• Out of silicon carbide• No external heater is necessary• Cooling System is necessary
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Globar
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http://www.refaccionesfernandosepulveda.com/linea-blanca/secadoras/secadora-varias-marcas/ignitor-globar-sirve-62040-we4x739-secadora-general-electric.html
IR‐Laser
Patrick Pues 1101/06/2016https://de.wikipedia.org/wiki/Liste_der_Lasertypen#/media/File:Commercial_laser_lines.de.svg
CO2‐Laser
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• CO2-N2-He Gas mixture
• Efficiency around 15 to 20%
• Material processing
https://de.wikipedia.org/wiki/Kohlendioxidlaser#/media/File:Co2_laser_energieniveau_schema.svg
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IR‐LED´s
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• First IR-LED in 1961 by Texas Instruments
• Based on GaAs
• Price was around 200 $
https://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Nernst_lamp.jpg/220px-Nernst_lamp.jpg
Detection of IR‐Radiation with Photodiodes
• Using p‐n junction• internal photoelectric effect• Cooling is sometimes needed• Filter are sometimes needed too
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Photodiodes
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https://de.wikipedia.org/wiki/Photodiode/
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Applications
• Heating• Remote‐control• Science• Astronomy• Photography• Military• Safety features
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Applications
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Summary
• IR‐All around us• Thermal radiators• IR‐LED´s • IR‐Laser
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Sources
• http://www.weltderphysik.de/gebiet/atome/elektromagnetisches‐spektrum/infrarotstrahlung/
• https://de.wikipedia.org/wiki/Infrarotstrahlung
• https://de.wikipedia.org/wiki/Photodiode
• http://www.troteclaser.com/de‐DE/Service/FAQs/Pages/Lasertypen.aspx
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IR‐Radiation
Sources &
ApplicationsPatrick Pues