Ruby Laser - Max Planck Institute for the Science of Light · [3] G.P. Agrawal, Nonlinear Fiber...

RubyLaser

Nd:YAG Laser

Nd:YAGLaser– ActiveMaterial

Nd3+ trappedinaYAGhost(typicaldopinglevel:1%atom).

Nd3+ SubstituteY3+ ionsinthecrystallinehostYAG=YttriumAluminumGarnet– Y3Al5O12

4-LevelLaserLevelsareprovidedby4felectronsofNd3+ andweaklyinfluencedbytheCrystallinestructure

[1]SpringerHandbookofLasersandOptics– TrägerEd.

LevelStructure

A.M.PARAMETERS: ��1k = 230µs

�e = 2.8⇥ 10�19cm�2

Nt = 1.38⇥ 1020 ions/cm2

�⌫ ' 0.15 THz

Nd:YAGLaser– SpectroscopyofActiveMedium

[1]SpringerHandbookofLasersandOptics– TrägerEd.[2]).Svelto– PrinciplesofLasers– 4th Edition

AbsorptionSpectrum

EmissionSpectrum

l=1064nm– PrincipalEmission

l=946nm–notsoenergetic(lamppumping)l=1319nm– notsoenergetic(diodepumping)

Roddiameter:3-6mmRodlength:5-15cm

YAG“Family”– DifferentActiveMaterials

ManyionscanbeusedtodopeYAGcrystal.thisgivesrisetoabroadvarietyofsolidstatelasersbasedonYAGhosts.

Differentdopingionscorrespondtodifferentwavelengths.

Nd:YAGLaser- Performances

REGIMES:CW– Q-Switch(10ns)– ModeLocked(psrealm– passiveML)[1]SpringerHandbookofLasersandOptics– TrägerEd.[2]O.Svelto,PrinciplesofLasers– 4th Edition

PUMPING:Lamps(XeforCWandKrforPulsedregime)->3%EfficiencyDiode(longitudinalandtransversalconfiguration)->10%Efficiency

OUTPUTPOWER:LampPumped:uptoafewkW(1-3kW)inCWDiodePumped:15W(CW)forlongitudinallypumpedabove100W(CW)fortransversallypumped

LampPumping

DiodePumping

Longitudinal

Transversal

Nd:YAGLaser– Applications(1/2)

DRILLING- QSMARKING

WELDING- QS

P 50-100 WE 5-10 J

⌧pulse 1-10 msRp 10-100 Hz

Upto2kW.GreatadvantagewithrespectToCO2 becauseNd:YAGcanbeconveyedinopticalfibers

[2]O.Svelto,PrinciplesofLasers– 4th Edition

Nd:YAGLaser– Applications(2/2)EYE-SURGERY

RESEARCH:AssubstituteofAr-Laserforpumping(Nd:YAGfrequencydoubled@532nm– green)

MEDICALAPPLICATIONS:Coagulationandtissueevaporation– CWupto50WPhotoablation(eyesurgery)- QS

RANGING- QS

E 100 mJ⌧pulse 5-20 nsRp 1-20 Hz

[2]O.Svelto,PrinciplesofLasers– 4th Edition

Er-Laser– Why?

[3]G.P.Agrawal,NonlinearFiberOptics– AcademicPress

SiO2 spectrum.Minimallossesat1.55µm

ThemostefficientLasersourceinthatregionisEr-Laser!

Opticalfibersarewidelyusedinopticaltelecommunicationsystems.TheyaremadeofSiO2.Weneedtofindagoodlasersourceattelecomwavelength(1.55µm)

Er:Yb:Glass/Fiber :NotpossibletodirectlyPumpEr3+.ResonantpumpWithYb3+Diodepumped@980nm

Er-Laser– Basics

Upperlevellifetime(Er:Yb:Glass)ca.8ms

TheErbiumLaserisathreelevelsystem!!!!

Erbium Ytterbium

ClassBlaser

ErbiumFiberLaser

Q-Switching[4]E 9 µJ

⌧pulse 420 nsRp 0.1-2 kHz

[4]Tzong-YowTsaiet.al.,Opt.Expr.18,10049(2010)[5]H.Zhanget.al.,Opt.Expr.17,17630(2009)

ModeLocking[5]E 7.3 nJ

⌧pulse 415 fsRp ' 6 MHz

Mainapplicationintelecomsystems!

Π polarization1

0.8

0.6

0.4

0.2

0Inte

nsity

[arb

. uni

ts]

wavelength [nm]400 500 600 700 800 900

Absorbance Fluorescence

Ti:Sa laser

Terminalmirror(flat) Terminalmirror(concave)

mirrorholder(endings)

Brewsterwindow

cathode

endofcapillary

gasdischargecapillary

Springs(tocenterthecapillaryend)

mirrorholder

glass-tube

He-NeLaser

HeNemixture~4-7mbarandaneoncontentof~10%

gamma= 6.6x106 s-1

k= 3.1x106 s-1

He-NeLaser

CO2laser

O OC

sym. stretching mode

O OC

antisym. stretching mode

O O

C

bending mode

(1000)

(0000)

(0200)

(0110)

(0001)

1000

2000

3000

0

∆E ~18 cm-1

10.6 µm

9.6 µm

v=0

v=1

CO2 N2

CO2 laser

gamma= 3x104 s-1

k= 9.6x106 s-1

gamma/k= 3.125x10-3

3levelsystem

Ruby Laser - Max Planck Institute for the Science of Light · [3] G.P. Agrawal, Nonlinear Fiber...

Documents

Transcript of Ruby Laser - Max Planck Institute for the Science of Light · [3] G.P. Agrawal, Nonlinear Fiber...