Toshihiko Baba

Yokohama National University

Photonic Crystalsand Si Photonics

Photonic Crystalsand Si Photonics

Toshihiko Baba baba@ynu.ac.jp

Yokohama National University http://www.dnj.ynu.ac.jp/baba-lab/babalabe.htm

Photonic Nanostructures

High Index Contrast Structure: HIC

n1

n0

n1

n0

Total reflection

Bragg reflection Bragg scattering

2D

Wire Disk Mesa

3D1D

1 m

Brillouinzone

X

X

UW

L

K

Γ

X

X

JΓ

1μm

1μm

1μm

Photonic Crystals: PC

0.2 μm

Holey fiber withsmall mode size

Mode size converter

MUX by super prismand superlens

Nanocavitydrop switch

Slowlightbuffer

Photonic crystal slowlight waveguide

Nanolaser, nanocavity, slow light waveguide,

negative refractive optics, etc. realize novel light

emitters and light control devices

Slowlightamplifier

Nanocavitycross-connect

Nanocavity-converter

Nanocavityadd switch

Nanolaser signal source

Integratedisolator

Electronics

Resonantphotodetector

Nanolaserfor -converter

Innovation in Photonic Integrationby Photonic Nanostructures

Innovation in Photonic Integrationby Photonic Nanostructures

Innovation in Photonic Integrationby Photonic Nanostructures

Photonic crystalnanocavity device

Silicon photonicsdevices

PC and HIC Silicon photonics allow densely

integrated advanced photonic chip

T. Baba, nature photonics 1, 22 (2007)

Photonic crystal slab

consisting of Airholes

Airbridge

membraneSubstrate

GaInAsP quantum well

active layer

Nozaki et al. EL 41, 15843 (2005); APL 88, 211101 (2006); OE 15, 7506 (2007)

Press released from OSA

Hz +–500 nm

Point shiftnanocavity

Laser Mode

Room Temperature CW Photonic Crystal NanolaserRoom Temperature CW Photonic Crystal NanolaserRoom Temperature CW Photonic Crystal Nanolaser

High Performance PC Nanolasers

RT, CW Lasing

Effective Pump Power Peff [μW]

Irradiated Power Pirr [μW]

Inte

nsity [

a.u

.]

Inte

nsity [

10

dB

/div

]

Wavelength [μm]1.57 1.631.60

Peff ~ 2.3 μW

40dB

0 50

0 1 2 3

(Nozaki, Kita and Baba, OE 15, 7506 (2007))

High Performance PC Nanolasers

RT, CW Lasing

Effective Pump Power Peff [μW]

Irradiated Power Pirr [μW]

Inte

nsity [

a.u

.]

Inte

nsity [

10

dB

/div

]

Wavelength [μm]1.57 1.631.60

Peff ~ 2.3 μW

40dB

0 50

0 1 2 3

(Nozaki, Kita and Baba, OE 15, 7506 (2007))

Single QD Lasing (LT)(Nomura et al., JSAP 31p-ZN-1 (2009))

1μm

Passive

Laser

WG

Active

Applications of Nanolaser

Light Source for Photonic IC

200 nm

PassiveActive

PC Slab

Air Clad.

Air Clad.

(Watanabe and Baba, OE 16, 2694 (2008))

Chemical and Bio-Sensing(Kita et al., OE 16, 8174 (2008); IPNRA, JMB3 (2009)) Cavity QED (Purcell enhancement, Rabi splitting,

single photon emission, quantum information)

1

0.1

0.3

0.2

0.7

0.5

Norm

aliz

ed Inte

nsity

0 1 2 3 4 5Time [ns]

Wafer

PC w/o cavity

Point-shiftnanocavity

@ = mode

RT, Pirr = 0.7Pth

(Baba et al. APL 85, 3989 (2004); Ota et al. APL 94, 033102 (2009))

Included in MEXT GCOE program operated by

YNU and collaborated with Univ. Oulu

Wavelength [nm]

No

rma

lize

d I

nte

nsity [

a.u

.]

1615 1625 1635

nenv

= 1.3061.315

1.3251.335

1.3451.355

5

4

3

2

1

0

< 26 pm

Wavelength [nm]

BSABinding

GlutaraldehydeModification

1586 1588 1590 1592

No

rma

lize

d I

nte

nsity [

a.u

.]

5

4

3

2

1

0

Micro-directionalcoupler with μmorder length

Micro-branchPhotonic crystalline defect waveguides

Point-defectmicrolaser

Micro-bend

High-Power Singlemode PC Bandedge Lasers

2D DFB PC allows over 30 W singlemode lasing

in large areas

Narrow beam profiles controllable by PC engineering

Ring shape FFP applicable to photon twizer and

tight focusing over the diffraction limit

(Noda et al., Science 293, 1123 (2001); Nature 441, 946 (2006); Science 319, 445 (2008); JSAP 31a-ZN-1 (2009))

Fabrication of 3D Photonic Crystals

Top Down Approach (Micromanipulation)(Aoki et al. Nat. Mat. 2, 117 (2003); Nat. Photon. 2, 688 (2008))

Bottom Up Approach (Lithographic Tech.)(Shoji et al. APL 76, 2668 (2000); Mizeikiz et al. OL 29, 2061 (2004))

Slow light inphotonic crystals

T. Baba, Nature Photonics 2, 465 (2008)

Si

Air

Si

Channel

(after Baba et al., EL 35, 654 (1999))

PC Line Defect Waveguide

(after Notomi et al., PRL 87, 253902 (2001))

Observation of slow light

1 μm

Wavelength [ m]

Gro

up Index n

g

1.550 1.555 1.560 1.5650

20

40

60

80

From F-Presonance

From modulationphase shift

1 μmL = 192 μm

Branch

Input

WG

Output

WG

ConfluenceCoupled Waveguide

2r1 = 0.24 0.26 μm

2r2 = 0.34 0.38 μm a = 0.46 μm

Photonic Crystal Coupled Waveguides (PCCW)

(Mori et al. OE 13, 9398 (2005); Kawasaki et al. OE 15, 10274 (2007))

Band shift in chirped structure

k k k0.29

0.30

a/2

c

0.3 0.4 0.5

Even

Odd

k [2 /a]

SlowLight

Lig

ht Lin

e

0 20 40 60 80 100Delay [ps]

Δτ [ps] = 3.2

2.3

2.1

2.2

3.3

3.3

3.4

4.1

2.2

2.3

3.0

3.26.4

4.7

5.24.5

4.1

3.5

2.3

P [mW], x [μm] = 7, 140

7, 151

6, 164

7, 169

31, 19

31, 26

35, 35

40, 37

12, 189

24, 171

37, 172

27, 163

27, 154

27, 151

37, 147

37, 144

38, 140

52, 140

58, 140

74 ps

No

rma

lize

d C

ross-C

orr

ela

tio

n I

nte

nsity [

a.u

.]

Δt

Δt

Inte

nsity

Inte

nsity

Δ

(Baba et al., OE 16, 9245 (2008);

Baba et al., Nature Photon. 2, 465 (2008);

Adachi et al., OSA SL, SWA1 (2009))

Δ

Δt

ΔT

Δt0 0

0 0

Slow chirp Fast chirp

Heating

Tunable Delay inSlow Light Pulse

Two Photon Absorption Self Phase Modulation

Optical Nonlinearity in LVLD Pulse

No Device

(Hamachi, Kubo, Baba, OL 34, 1072 (2009))

Nonlinearity is enhanced by SL pulse in LVLD waveguide (350 m length)

TPA scales with ng2 and >40-fold higher than Si photonic wire waveguide

eff [cm/GW] =3

0

10

25

50

00

0.5 1.0 1.5 2.0Input Peak Intensity Pin [W]

Outp

ut P

eak Inte

nsity P

ou

t [W

]

0.5

1.0

ng ~ 30

ng ~ 30

ng ~ 8

ng ~ 8

1.890.750.300.12

Tra

nsm

issio

n [5 d

B/d

iv]

Wavelength λ [μm]

1.5511.551 1.554

Pin [W] =

1.551 1.554 1.554

PC Nanocavity-Waveguide Coupled System

Ultrahigh-Q Nanocavity (Tanabe et al. Nat. Photon. 1, 49 (2007); Takahashi et al. OE 15, 17206 (2007))

Nonlinear bistable switching(Notomi et al. OE 13, 2678 (2005); OL 30, 2575 (2005)) Dynamic Tuning

(Tanaka et al. Nat. Mat. , 862 (2007))

Q factor up to 3,000,000 and photon storage of 2 ns

Carrier-induced bistability, τ=100ps, Wth=10fJ Stopping optical pulse observed

Negative Refraction inPhotonic Crystals

Negative Refraction inPhotonic Crystals

Functions Predicted from Dispersion Surfaces

(after Kosaka et al., PRB 58, 10096 (1998))

0.6

0.56

0.64

0.82

0.80.74

0.760.72

0.70.7

0.72

0.74

1 2 3

4 5 6

0.1

0.2

0.55

0.54

0.53

Isotropic Propagation

Superprism

Superlens

Slowlight

Super-Collimation

Observation of Negative Refraction

(Matsumoto et al., APL 91, 091117 (2007))

10 μm

De

fle

ctio

n A

ng

le θ

[º]

Wavelength λ [μm]

45

50

55

60

65

Plot: Experiment, Line: FDTD

1.50 1.601.55

2r =

0.3

0 μ

m

0.2

9 μ

m

0.2

7 μ

m

1 μm

24º

PC

Si Slab

InputWG

λ = 1.37 μm

PC

Si Slab

θ

1 μm

Light Focusing in PC Superlens

PC slab superlens

15

10

50

L [

m]

3 2 1 0

Position [ m]Inte

nsity [

a.u

.]

0

1

-10 0 10

2.0 m

(Matsumoto, et al. OL 31, 2776 (2006))

0.5 μm

= 1.305 μm

Intensity [a.u.]

Photonic Nanostructures

High Index Contrast Structure: HIC

n1

n0

n1

n0

Total reflection

Bragg reflection Bragg scattering

2D

Wire Disk Mesa

3D1D

1 m

Brillouinzone

X

X

UW

L

K

Γ

X

X

JΓ

1μm

1μm

1μm

Photonic Crystals: PC

0.2 μm

Photonic Wire Waveguide Elements

(Sakai et al. JJAP 40, L383 (2001)) (Yamada et al. IEEE JSTQE 12, 1371 (2006))

SEM NFP

(Sakai et al. IEICE Trans.E85-C, 1033 (2002); JJAP 41, L1461 (2002))

Y Branch and H-TreeBend

NFP = 1.55 m

(Fukazawa et al. JJAP 43, 646 (2004))

10.4 μm

1.6 μm

0.4 dB

30 dB

Intersection

MMI Coupler

MZ Interferometer

N = 50L = 17.2 m

5 m

(Ohno et al., JJAP 44, 5322 (2005))

Directional Coupler(Yamada et al., IEEE PTL 18, 585 (2005))

(Tsuchizawa et al. EL 38, 1669 (2002))

Spot Size Converter10 m = 1.55 m

(Xiao et al., JLT 26, 228 (2008))

Microring

(Bogaerts et al. OE 12, 1583 (2004))Grating Coupler

(Yamada et al. IEICE Trans.E87-C, 351 (2004))

Si Photonics Functional Devices

MUX/DEMUX (AWG)

10 μm1.50 1.55

Wavelength [μm]

Tra

nsm

issio

n [dB

]

10

20

30

0

1.60

(Fukazawa et al., JJAP 43, L673 (2004); JJAP 45, 6126 (2006))

(Liu et al. APL 87, 011110 (2005))

Epitaxial Ge Detector(Fang et al., OE 14, 9203 (2006))

III-V Hybrid Laser

20 GHz bandwidth

(Yamada et al., IEEE PTL 18, 1046 (2006))

Nonlinear Elements(FWM, Raman, TPA, SPM...)

Modulator

10 Gbps

Eye Pattern

(Liao et al., OE 13, 3129 (2005))

Delay Line and Optical Buffer (Xia et al., Nature Photon. 1, 65 (2007))

Open Foundry Now Available

Sept. ’08 May ’08 Sept. ’08 (pre. ’06-)

e-beam100 kV photo. 248 nm photo. 193 nm

WG width > 80 nm > 170 nm > 120 nm

fIber coupling facet with SSC

(< 2.5 dB/facet)

facet with SSC

(< 2.5 dB/facet)

facet with SSC,

grating coupler

(< 5.2 dB/facet)

NTT-ATN

(Japan)

JSPS Center of Si Photonics Prog.

Japan: U.Tokyo, Yokohama U., etc.

USA: MIT, Rochester, etc.

Europe: IMEC etc.

Test suttle run by NTT-ATN

8000 USD / 2 chips, 6 dB loss inc. lens coupling

started from

lithography

? available availablelithography

Silicon Photonics

MPW Prototyping/IME

(Singapole)

ePIXfab / IMEC

(Bergium)

Air SSC

PC Nanolaser

PC Negative refractive opticsFocusing, image formation, beam steering, collimating Compensation of aberration possible

HIC Silicon photonics deviceμ-components based on Si photonic wire waveguide Functional devices, applications to opt. interconnectsFoundry service now available

Topics

PC Slowlight waveguideWideband dispersion-free slow light pulse availableTunable delay available by TO effectDynamic control expected for more delay

Ultralow threshold RT CW lasing and Purcell effectA/P integation for photonic integrated chipHight resolution sensing available