OutlineIntroduction

Sources of Infrared radiation

Sources of Infrared radiation

Michael Bentlage

May 19, 2008

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

1 Introductionhistorical backgroundclassi�cation of the spectral range

2 Sources of Infrared radiationblack body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

historical backgroundclassi�cation of the spectral range

historical background

1800 Sir Wilhelm Herschel: Discovers IR-radiation

1859 Gustav Kirchho�: Derives the law of thermal radiation

1893 Wilhelm Wien: Derives the displacement law

1897 Walther Nernst: Invents the Nernst Glower

1901 Max Planck: Derives Plancks Law

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

historical backgroundclassi�cation of the spectral range

classi�cation of the spectral range

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

black body radiators

absorb any incident light

ideal source for thermal radiation

Plancks law: I (λ,T ) = 2hc2

λ51

ehc

λkT −1I: Intensity of corresponding wavelength at a given temperatureh: Plancks constantc: speed of lightλ: wavelengthk: Boltzmanns constantT: Temperature

Wiens displacement law: λmax = 2897,8µmK

T

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

examples for black body radiators

Humans

peak value = 9.3µm

almost no intensity in thevisible

applications:

motion detectorstemperaturemeasurementInfrared cameras

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

examples for black body radiators

Humans

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

examples for black body radiators

Incandescent lamps

peak value = 1.1µm(T = 2700K)

peak value = 966 nm(T = 3000K)

main part of radiation inthe infrared

applications:

medicine & agriculturephotography

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

examples for black body radiators

Incandescent lamps

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

examples for black body radiators

The sun

peak value = 500 nm(T = 5800K)

real spectrum exhibitsFraunhofer lines

applications:

solar panels

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Nernst lamp

composition

Zirconium oxide ZrO290%wt/wt

Yttrium oxide Y2O37%wt/wt

Erbium oxide Er2O33%wt/wt

operating temperature: 2300K

preheating necessary

applications

general lighting purposes�rst functional long distance faxophthalmologyprojectionmicroscopy

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Nernst lamp

peak value = 1.3µm(T = 2300K)

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Nernst glower

application in Infrared spectroscopy

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Globar

Glow + bar = Globar

composition

Silicon carbide

operating temperature: 1400K

no preheating necessary

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

Globar

peak value = 2.1µm(T = 1400K)

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

IR-LEDs

IR-LEDs can be made outof III/V-semiconductors

applications

remote controlsphotoelectric sensors

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

IR-Lasers

IR-Lasers utilize the following technologically relevantwavelengths

850 nm, 1300 nm, 1310 nm, 1550 nm and 1625 nm

applications

Telecommunication

Michael Bentlage Sources of IR-radiation

OutlineIntroduction

Sources of Infrared radiation

black body radiatorsexamples for black body radiatorsNernst lampGlobarIR-LEDs and -lasers

End

Thanks for your attention.

Michael Bentlage Sources of IR-radiation