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Light from the edge:Light from the edge:a 3-D investigation of 2-D organic micro-billiard lasersa 3-D investigation of 2-D organic micro-billiard lasers

Clément LafargueClément Lafargue11, S. Lozenko, S. Lozenko11 , S. Bittner , S. Bittner11, C. Ulysse, C. Ulysse22, C. Cluzel, C. Cluzel33, J. , J. ZyssZyss11, M. Lebental, M. Lebental11

1 – Laboratoire de Photonique Quantique et Moléculaire, ENS de Cachan.1 – Laboratoire de Photonique Quantique et Moléculaire, ENS de Cachan.

2 – Laboratoire de Photonique et de Nanostructures , CNRS, Marcoussis.2 – Laboratoire de Photonique et de Nanostructures , CNRS, Marcoussis.

3 – Laboratoire de mécanique et technologie, ENS de Cachan.3 – Laboratoire de mécanique et technologie, ENS de Cachan.

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Conventional laser

Amplifying medium

ResonatingCavity

Dye-doped polymer micro-cavity

weak confinement n ≈ 1.5

Organic microlasersOrganic microlasers

Usual configuration

+

3

Chaotic cavitiesChaotic cavities

LPQM – microlaser group topicsLPQM – microlaser group topics

Numerical modelingNumerical modelingS.LozenkoS.Lozenko

““Microfluid”Microfluid”EU ProjectEU Project

Analyte solution flow

EmissionEmissionDiffractionDiffraction

Unidirectional lasingUnidirectional lasing

N.Djellali, N.Djellali, APL APL 9595, 101108 (2009), 101108 (2009)

Lebental,Lebental, APL APL 8888, 031108 (2006), 031108 (2006)

POSTER, I. Gozhyk :Towards the control of polarization properties of solid state organic lasers

I. Gozhyk, PRA I. Gozhyk, PRA 8686, 043817 (2012), 043817 (2012)

Measurement and modelMeasurement and modelPOSTER, S. Bittner :Localization of modes in a dielectric square resonator

Semi-classical modelingSemi-classical modeling

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n1n1n2n2

Dielectric cornerDielectric corner

Motivation: diffraction at dielectric corners and edgesMotivation: diffraction at dielectric corners and edges

no solutionno solution

A standing wave in a resonator to explore the cornerA standing wave in a resonator to explore the corner

Metallic cornerMetallic corner

SommerfeldSommerfeld18961896

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1)1) Background on organic microlasersBackground on organic microlasers• FabricationFabrication• ExperimentExperiment

2)2) Emission/diffraction propertiesEmission/diffraction properties• Fabry-Pérot like cavities• Square cavities

3)3) Triangular microlasers Triangular microlasers

OutlineOutline

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OutlineOutline

1)1) Background on organic microlasersBackground on organic microlasers• FabricationFabrication• ExperimentExperiment

2)2) Emission /diffraction propertiesEmission /diffraction properties• Fabry-Pérot like cavities• Square cavities

3)3) Triangular microlasersTriangular microlasers

7Organic microlaser: FabricationOrganic microlaser: Fabrication

Fabrication: Electron-beam lithographyFabrication: Electron-beam lithography

50-200 µmMicroscope photograph SEM photograph

1μm

0.6 µm

• Arbitrary cavity shapes• Different laser dyes

Cavity n≈1.5PMMA + Dye

SiO2n=1.45

n2=1

0.6-0.7 μm

50-200 µm

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532 nm

~610 nmemission

Spectrometer

collecting lens

Organic microlasers: characterizationOrganic microlasers: characterization

pumping

Excitation geometry

Lasing thresholds

Emission diagrams

Spectrum L

Wavelength [nm]Images

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0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

0

1000

2000

3000

4000

5000

Inte

nsity

(co

unts

)

Pump energy (uJ)

Lasing thresholds

Emission diagrams

Spectrum L

ExperimentalExperimentalMeasurementsMeasurements

Images

Organic microlasers: characterizationOrganic microlasers: characterization

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Physical Review A 75, 033806 (2007)

FAR FIELD DETECTIONFAR FIELD DETECTION Lasing thresholds

Emission diagrams

Spectrum L

ExperimentalExperimentalMeasurementsMeasurements

Images

Organic microlasers: characterizationOrganic microlasers: characterization

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Semi-classical approachSemi-classical approach

Periodic OrbitsPeriodic Orbits

PRA 76, 023830 (2007)

Lasing thresholds

Emission diagrams

Spectrum L

ExperimentalExperimentalMeasurementsMeasurements

Images

F.S.R.F.S.R.

Organic microlasers: characterizationOrganic microlasers: characterization

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Lasing thresholds

Emission diagrams

Spectrum L

ExperimentalExperimentalMeasurementsMeasurements

Organic microlasers: characterizationOrganic microlasers: characterization

Images

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OutlineOutline

1)1) Background on organic microlasersBackground on organic microlasers• FabricationFabrication• ExperimentExperiment

2)2) Emission/diffraction propertiesEmission/diffraction properties• Fabry-Pérot like cavities• Square cavities

3)3) Triangular microlasersTriangular microlasers

143D emission- latitude diagrams3D emission- latitude diagrams

Measurement:Measurement:

FPFP

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Sergey Lozenko J.A.P. 111, 103116 (2012)

Measurement:Measurement:

FPFP

x

z

3D emission- latitude diagrams3D emission- latitude diagrams

163D emission - latitude diagrams3D emission - latitude diagrams

FPFP

C. Lafargue, to be submitted

Model: Slit diffractionModel: Slit diffraction

Interference (wafer)

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OutlineOutline

1)1) Background on organic microlasersBackground on organic microlasers• FabricationFabrication• ExperimentExperiment

2)2) Emission/diffraction propertiesEmission/diffraction properties• Fabry-Pérot like cavities• Square cavities

3)3) Triangular microlasersTriangular microlasers

18Square microlaser : diffractive outcouplingSquare microlaser : diffractive outcoupling

1.0

0.5

0.0

Fo

urie

r tr

ansfo

rm

25002000150010005000Optical length (µm)

nLnL

a

= n x 2√2 a

Diamond orbit confined by total internal reflection …

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… … but losses occur via diffractionbut losses occur via diffraction

Diamond orbit confined by total internal reflection …

Square microlaser : diffractive outcouplingSquare microlaser : diffractive outcoupling

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CameraCamera

Pump :Pump :

Pump polarization effectsPump polarization effects I. Gozhyk, PRA 86, 043817 (2012),

Square microlaser : diffractive outcouplingSquare microlaser : diffractive outcoupling

21Square microlaser : diffractive outcouplingSquare microlaser : diffractive outcoupling

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OutlineOutline

1)1) Background on organic microlasersBackground on organic microlasers• FabricationFabrication• ExperimentExperiment

2)2) Emission/diffraction propertiesEmission/diffraction properties• Fabry-Pérot like cavities• Square cavities

3)3) Triangular microlasers Triangular microlasers

23Periodic Orbits in trianglesPeriodic Orbits in triangles

• A not so simple shape (not regular contour)A not so simple shape (not regular contour)

• No totally confined periodic orbitsNo totally confined periodic orbits

• An open mathematical question: An open mathematical question: « Does a periodic orbit in a triangle exist ? »« Does a periodic orbit in a triangle exist ? » Alain Grigis, University Paris XIIIAlain Grigis, University Paris XIII

24FP winningFP winning

100°

40° 40°

25FP not always winningFP not always winning

Despite the fact FP is in family, the other isolated orbit is winning

110°

35°35°

Camera view

110°

26Diffractive orbitDiffractive orbit98.04°

41.96°40°

27SummarySummary

1)1) Diffraction effects from the edges on different contours :Diffraction effects from the edges on different contours :• 3D Fabry-Pérot emission well understood3D Fabry-Pérot emission well understood• Square : emission at the corners Square : emission at the corners • 3D emission depends on the cavity shape3D emission depends on the cavity shape

2)2) TrianglesTriangles• Identification of orbits • Switching between different types of orbits• Observation of a diffractive orbit

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clement.lafargue@ens-cachan.fr

PerspectivesPerspectives