Cavity soliton switching and pattern formation in an optically-pumped vertical-cavity semiconductor...
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Transcript of Cavity soliton switching and pattern formation in an optically-pumped vertical-cavity semiconductor...
Cavity soliton switching and pattern formation
in an optically-pumpedvertical-cavity semiconductor
amplifier
Laboratoire de Photonique et de NanostructuresLPN-CNRS/UPR20, Marcoussis, France
S. Barbay, Y. Ménesguen, X. Hachair, L. Leroy, I. Sagnes, R. Kuszelewicz
Introduction
Cavity solitons : self-localized structures high intensity peaks on a low intensity background in a
large diameter cavity
Properties :
Independant of each other
Can be written & erased by control beam
Can be manipulated by phase gradients
Applications
Phase gradient
Pulsed beam
Optical delay lineSerial to parallel conversion
Reconfigurable optical memory Control beam
Holding beam phase profile
VCSOA characteristics
Nonlinear cavity with large Fresnel number injected by coherent beam (holding beam)
F a²R
1
a
R
~100 m
~10 m
substrate
GaAs
Reflected beam
Control beam
Holding beam
Bragg MirrorBragg Mirror
Pump
Optical pumping
pump uniformity
thermal management
2aF
R
Theoretical model
[M. Brambilla, L. Lugiato, F. Prati, L. Spinelli, W. Firth, PRL 79, 2042 (1997)]
E : intracavity electric field
N : carrier density
= 1 transparency = 1+1/2C laser threshold
coupling to the cavity
radiation-matterinteraction diffraction
carrier recombinationnon-radiative radiative carrier diffusion
Injected field/holding beam
2
22 2
(1 ) 2 ( )( 1)
( ( 1) )
iE
i E E iC i N E i EtN
N N N E D Nt
Modulation Instability
Intracavity I
k
i
PWI
MICS Rolls+Hex.
= 5, = -2, C = 0.45, = 2
Injected I
Intracavity I
Sample : OP-VCSOA on SiC substrate
Ti:Sa injection @ 883.93nm
12 mm
MOCVD grown AlGaAs microcavity with GaAs active medium
Optimized aperiodic mirrors : optical pumping efficiency, heat managementSubstrate bonding on SiC
[S. Barbay,Y. Ménesguen, I. Sagnes, and R. Kuszelewicz, App. Phys. Lett. vol 86, 151119 (2005)]
Laboratoirede Photonique et de Nanostructures
Pattern formation
890.98 nm 889.95 nm 889.27 nm
888.23 nm
Pump + coherent injectionPump
120 m
Laboratoirede Photonique et de Nanostructures
Local intensity vs
injection beam intensity
Injected intensity
Loc
al in
tens
ityBistability
Laboratoirede Photonique et de Nanostructures
Periodic coherent writing / erasure of a single CSO
utpu
t int
ensi
ty
Injected intensity
phase shifted local excitation
in phase local excitation
Coherent injection
Optical pump
Local pulsed excitation
sample plane
Laboratoirede Photonique et de Nanostructures
Periodic coherent writing / erasure of a single CS with 100ns pulses
Local intensity
Writing pulse phase mismatch
100ns pulses trigger
Laboratoirede Photonique et de Nanostructures
Incoherent writing / erasure
Can we write with incoherent local excitation ?
Cavity solitons in optical amplifiers are coherent objectsbut...
one can play on carriers
Laboratoirede Photonique et de Nanostructures
Incoherent Writing with short pulses
60 ps writing pulse60 ps writing pulseLocal pump modulation
Laboratoirede Photonique et de Nanostructures
Fast incoherent writing : 60ps pulses
CS off
CS on~2ns
Laboratoirede Photonique et de Nanostructures
Fast incoherent erasure : 60ps pulses
CS on
CS off
~5 ns