ultrafast nonlinear optical processing in photonics
TRANSCRIPT
Ultrafast nonlinear optical processing in photonics integrated circuits:
Benjamin Eggleton
p gSlow light enhanced
j ggARC Laureate Fellow
Director, CUDOS - Australian Centre of Excellence Centre for Ultrahigh bandwidth Devices for Optical SystemsCentre for Ultrahigh-bandwidth Devices for Optical Systems
Institute of Photonics and Optical Science (IPOS)S h l f Ph i U i it f S dSchool of Physics, University of Sydney
Eggleton group
Ultrafast coherent communications
Quantum integrated photonics
Nonlinear opticalPhononics (SBS)
communications
photonics
Nonlinear optics Nanophotonics
Chip-based ultrafast nonlinear optics
• The photonic equivalent of an ultrafast integrated circuit:
– Femtosecond optical response– Millimetre scale optical circuits
To achieve these we need:• To achieve these, we need:
Ultrafast light-light interaction (10-12s)Optical
response
Ultrafast light light interaction (10 s)
Waveguides in novel nonlinear materialsg
Photonic crystals (slow light enhanced NL)
Ultra-fast Kerr nonlinearity• Nonlinear optics provides ultra-fast manipulation of light (e.g. switching,)
)3()2()1( EEEEEEP
n = n + n I (Intensity dependentf i i d )
...0 EEEEEEP
n22 n = n0 + n2I refractive index)
Self-phase modulation (SPM)C ( )
effA
Cross-phase modulation (XPM) Phase matched processes (Four-wave mixing)
Third harmonic generationgRaman Scattering
Brillouin Scatttering
Planar waveguides As2S3
• Deposition of As2S3 film – Thermal evaporation
• Photolithography & dry etching• Photolithography & dry etching– n2~110×silica – Effective Area: ~1-5 µm2
– γ=2000 –25 000 W-1km-1γ=2000 25,000 W km– Prop. loss ~0.05-0.2db/cm– Dispersion engineered
Serpentine waveguide = 22 cm (~3dB loss)
Slow-light enhancement of NL effects
– Longer interaction time with material
vg~vphase
v <<v
• Effective nonlinearity ~ (slow-down factor)2
S ti l l i
vg<<vphase
– Spatial pulse compression – Enhanced interaction (path length)– Ultra-compact operations and potentially energy efficient– Ultra-compact operations and potentially energy efficient
Planar photonic crystal waveguides
• Planar photonic crystal:Slab (220nm)+2D PhC (air hole lattice a~400nm)
• Sub-µm optical confinement Aω ~0.4 µm2 Light
(k ) Vlasov et al. Nature 2005
(k,)
Even mode
kvg
Coherent backscattering
Flat band = Slow light
k
k [2/a]0 0.5= Slow light
Krauss J. Phys. D 2007
Slow light versus resonatornonlinear enhancement
Slow light dispersion engineered waveguides
Resonators: bandwidths from kHz to at most a few GHz....
1µm Carmon et al. Nature Physics 2007
vg~c/4010%10nm (1.2 THz) band 26µm
cw demonstrationsNarrow linewidth
( )« Flat-band »
Slow light
1µm
Application to high bit rate all-optical signal processing
Galli et al. Opt Express 18, 26613 (2010)
Conversion efficiency ~2.10-8
(100W in cw)
High bandwidth of the slow light PhC wgd
50
60
0
10640Gb/s 33% RZ Corcoran et al. Opt Express 18, 7770 (2010)
40
(ng)
-10
Po
30
oup
Inde
x
-30
-20
ower (dB
m
10
20Gro
-40
)
640Gb/s 33% RZ
0
10
1545 1550 1555 1560 1565 1570-60
-50
3dB BW ~ 7.5nm
1545 1550 1555 1560 1565 1570Wavelength (nm)
Principle of OPM monitoring
Slow Si PhotodiodePhotodiode
40 Gbit/s to 640Gbit/s signal640Gbit/s signal
ħωT
ħωT
ħωħωħωT
ħωT
ħωħω
ConstantTotal Av powerIn-band
ASE noise
Total Av. power ~ 100mW (input)/ ~10mW (coupled)
Corcoran et al. Opt Express 18, 7770 (2010)
OSNR/dispersion Monitoring
160Gbit/s14%
160Gbit/s14% duty cyclecycle
640Gbit/s33%
THG induced green light:A clear function of the di i /OSNR i d ddispersion/OSNR induced distortion of the signal
Corcoran et al. Opt Express 18, 7770 (2010)
PSA in Silicon PhC Waveguides
Gai
n
propagating phase
ωs ωi ωp 0 ϕ πPSA gain
PhCPhC + TPA = PSA ?+ TPA = PSA ?Slow light enhances nonlinearity
10
/ )
TPA limits nonlinearityPhCPhC + TPA = PSA ? + TPA = PSA ?
5
hase
shi
ft (
/TPA
No TPA
Krauss J. Phys. D 40 2666 (2007) 0 5 100Power (W)
ph TPA
PSA setup
TE
30 nm
SPSEDFAPC
SPS OSALaser
40 MHzPump: 15ps, 1W(peak)Signal/idler:8ps 10/20mW(peak)Signal/idler:8ps, 10/20mW(peak)
PSA in Silicon PhC Waveguides(postdeadline OECC 2013)
0
2
4
-40
-30
)
0.7
-40
-30
)
0.70.5-40
-30
)
0.70.50.2
-40
-30
)
0.70.50.2 +Gain
-4
-2
0
Gai
n (d
B)
-60
-50
nten
sity
(dB
)
-60
-50
nten
sity
(dB
)
-60
-50
nten
sity
(dB
)
-60
-50
nten
sity
(dB
)
10 dB
0 0 2 0 4 0 6 0 8 1-10
-8
-6
1552 1554 1556 1558 1560-80
-70
In
1552 1554 1556 1558 1560-80
-70
In
1552 1554 1556 1558 1560-80
-70
In
1552 1554 1556 1558 1560-80
-70
In
-Gain0 0.2 0.4 0.6 0.8 1
/1552 1554 1556 1558 1560
(nm)1552 1554 1556 1558 1560
(nm)1552 1554 1556 1558 1560
(nm)1552 1554 1556 1558 1560
(nm)
0
2
4
Max gainGain:
-6
-4
-2
Gai
n (d
B)
Mi i
11 dB
0 0.5 1 1.5-10
-8
Peak Power (W)
Min gain
Soliton compression in silicon photonic crystals
Key Points:-- Solitons possible in Si
(i) (strong FC disturb ideal Kerr-GVD dynamics)(ii) Spectral blue shift due to free-carriers [1 2]
N > 1 (compression regime)N2 = Ld / LNL
Ld=T02 / |2|
LNL=1 / (eff P0)
-- Frequency-resolved gating--Increasing power
(ii) Spectral blue shift due to free carriers [1,2](iii) Time domain acceleration [1]
-- Picojoule pulse energiesChallenging to measure these small pulse energie(< pJ collected off chip)
NL (eff 0)
EXPERIMENT (Time domain)Power coupled to PhC (< pJ collected off-chip)
--NLSE modelling underway
Power coupled to PhCEo ~ 10 pJ, c ~ 2
1.7 ps
Silicon
Dr Chad Husko
Silicon
See also:
Dr. Chad Husko(DECRA fellow)
Andrea Blanco(Marie CurieVisiting Ph.D.)
Dan Eades(Undergrad)
[1] Husko et al., Scientific Reports 3, 1100 (2013) – GaInP PhCsolitons
[2] Husko et al, CLEO US - QF1D.5 (Friday 9:15 AM)[3] Ding et al (Bath), Opt. Exp. 18, 26625 (2010) – Si wire WG
3.65 ps
Quantum integrated photonics
Tb/s coherent communications
Create world’s first photonic platforms for practical, scalable quantum information operations for secure communications based
Free space optics
Q t
Mid IR integrated
communications
Q t i t t d
pon single photons
Quantum integrated photonics
photonicsQuantum integrated photonics
Zeilinger et al, Quantum teleportation experiment
Photon pair generation by nonlinear mixing
Hybrid integration
Nanophotonics
Integrated platform
Heralded single photon sources
(3): Spontaneous four-wave mixing (SFWM)
H ld(3) medium
Herald2 Pump photons
DetectorsDetectors
Silica PCF Rarity, Opt. Express (2005).Silicon Waveguide Sharping, Opt. Express (2006).
Single PhotonSFWM!Input
Outputg p g, p p ( )
Silicon Rings Clemmen, Opt. Express (2009).Silicon Nanowire Harada, IEEE JSTQE (2010)Chalcogenide Waveguide Xiong, Opt. Letters (2010)Silicon Photonic Crystal Xiong, Optics Letters (2011).
pi sp pi sy g, p ( )
Silicon CROW Davanço, APL (2012).
Postdeadline CLEO 2011, BaltimorePostdeadline ECOC 2012 Amstedam
~centimeters
InputIdler and signal = pairs of correlated photons
Output
Spatially compressed pump pulse
centimeters
p
Output
p
pi s
Slow light Enhancement of the nonlinear FWM efficiencySlow light
“Fast” light
Slow light Enhancement of the nonlinear FWM efficiency
Ultra-compact sources (~100m)
Fully integrated multiplexed single photon source
RF CMOS electronic logicSPDs C. Schuck, et. al., APL 102, p. 051101, 2013.
Pulsed pump laserlaser input
Heralded single gphoton outputNoise
porthttp://www.singlequantuN Silicon PhCW’s
Integrated AWG’s
FiberDelay
Low loss PLZTNx2 switch
portD. Dai et. al.,OpEx, 9, no. 15, p. 14130, 2011.
m.com/
• Multiplexing allows us to take probabilistic photon-pair sources and make asources and make a deterministic single photon source.
Further IntegrationC lli l N C i i i
196µm
63.1% enhancementCollins et al. Nature Communications, in-press.
196µm
g(2)(0) = 0.17
vg
λ
Highly nonlinear chalcogenide glass
Our work: As2S3, As2Se3, Ge11As22Se67
High nonlinearity (ultra-fast ~ 50 fs response) n2 ~ 100-1000 x silica
Ultrafast pure Kerr effect (no free-carriers)
Low two-photon absorption Low two-photon absorption
Compatible with Photonic integration
Ultra-strong Raman/Brillouin scattering Ultra strong Raman/Brillouin scattering
Mid-infrared transparent (2-10m)
Heralded single-photon generation
Coincidence to accidental ratio (CAR)
CAR > 350
Si PhCW
L 196CAR > 350 L = 196 µmϒ ~ 4000 W-1m-1
1. A. Clark et al, New J. Phys. 97, 211109 (2011)2. C. Xiong et al, Appl. Phys. Lett. 98, 051101 (2011)3. C. Xiong et al, Opt. Lett. 36, 3413 (2011)
Solution: Spatial multiplexing
B l b lti l i
Spontaneous nonlinear process: • nondeterministicUltra-compact on-chip single-photon sourcesBalance by multiplexing• high photon number state
Ultra compact on chip single photon sources
Nonlinear Fast feed-forward On demand l Nonlinear
Sources optical switch
Single mode
pump pulses(all from 1 laser) Detectors
Single modeOn demand Single photons!
Sources that randomly
Migdall Phys. Rev .A 66, 053805 (2002)
Sources that randomly generate photons
053805 (2002)PROPOSAL