trends in future communicationsinternational workshop - renato rabelo
TRANSCRIPT
Trends in Future Communications
International WorkshopCPqD - Campinas
Renato Cunha Rabelo, PhD – IEAv-DCTA24/02/2014
Outline
• IEAv/DCTA
• Lithium Niobate Filters
IEAv
EAH ENU EFA EFO ESTEGI
IEAv
EAH ENU EFA EFO ESTEGI
Institute for Advanced Studies
IEAv
EAH ENU EFA EFO ESTEGI
Institute for Advanced Studies
Mission: Build scientific knowledge and develop strategic technology capableof strengthening Brazilian aerospace competence.
IEAv
EAH ENU EFA EFO ESTEGI
Photonics Division
IEAv
EAH ENU EFA EFO ESTEGI
Photonics Division
Generate, control and detect light
IEAv
EAH ENU EFA EFO ESTEGI
EFO-LEFO-SEFO-O
PhDs Masters Graduates Technicians
EFO-L 07 03 03 04
EFO-O 04 02 0 03
EFO-S 05 05 0 03
Total EFO 17 10 03 10
MANPOWER
40
Collaborators
Postdocs MSc / PhD Students
Graduates / MSc
Students
UndergradStudents
EFO-L 01 10 04 06
EFO-O 1 0 0 10
EFO-S 02 0 2 02
Total EFO 04 10 06 1838
Spectral Slicing Filters in Titanium Diffused Lithium Niobate (Ti:LiNbO3)
Waveguides
WDMFiber Optic Communication link
1ReceiverTransmitter1
Optical Fiber
Transmitter2
Transmittern-1
Transmittern
2Receiver
n-1Receiver
nReceiver
. .
. . .
.
MU
XD
EM
UX
DWDM Channels
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
0.0
0.2
0.4
0.6
0.8
1.0+6-6 -5 -4 -3 -2 -1 +10 +3+2 +5+4
Am
plitu
de (
a.u.
)
Normalized Frequency (-0) X 100 GHz)
TE-TM Mode Conversion:
LiNbO3
Ti diffused Waveguide
x y
z
TE
TM
L
SiO2 Strain inducing grating
TE-TM Mode Conversion:
unconvconv
conv
PP
PPCE
)0(
)0(
sin2
cossin
sinsin2
cos
)(
)(
2/2/
2/2/
B
A
yjyeyje
yjeyjye
yB
yA
yjyj
yjyj
)()(0
0 TMTETMTE nnnnv
c
0
2)(2
c
nnv TMTE
2)(2
c
nnv TMTE
)0(
)0(
cossin
sincos
)(
)(
B
A
LLj
LjL
LB
LA
LL
L
22
2
cossin
sin
L2sin
TE-TM Mode Conversion:
-12 -8 -4 0 4 8 120.0
0.2
0.4
0.6
0.8
1.0P
ola
riza
tion
Co
nve
rsio
n E
ffici
en
cy
Normalized Frequency (() x 100 GHz)
Fabrication Steps
Titanium Deposition(DC sputtering)
LiNbO3
Ti t Patterning(Photolithography)
DiffusionLiNbO3
Ti t
LiNbO3
Ti
LiNbO3
Heatand Time
LiNbO3
SiO2
Silica Deposition(E-beam evaporation)
@ High Temp
Cool-down toRoom Temp.LiNbO3
SiO2
Surface Strainbuild-up
SiO2 < LiNbO3
Patterning(Photolithography)LiNbO3
SiO2
(Side view) LiNbO3
SiO2SiO2SiO2SiO2 SiO2 SiO2
Conversion EfficiencyTest Setup
Er+ doped fiber
Laser DiodePump @ 980 nm
OSA
Sample under test
Objective
WDM 980/1550coupler
PZ fiber
Objective
Polarizer
Amplified Spontaneous Emission light source
Isolator
Conversion EfficiencyTest Setup
Conversion EfficiencyTest Results (Uniform Grating)
TM TM
TM TE
TE TE
TE TM
Conversion EfficiencyTest Results (Uniform Grating)
22
2
)()(
)(
zBzA
zB
utputr at the oTotal powe
ion power polarizat ConvertedPCE
1528 1530 1532 1534 1536 1538 15400.0
0.2
0.4
0.6
0.8
1.0
W/G 5 - Linear ScaleRoom Temperature500 elements
TE input/TM output TM input/TE output Theoretical Response
Pol
ariz
atio
n C
onve
rsio
n E
ffici
ency
Wavelength (nm)
Conversion Efficiency = 99.8%
@ 1533 nm
Device Fabrication
Conversion Efficiency
•Coupling coefficient had to be adjusted
dxdzEE TMpert
TE
Critical Parameters:1. Titanium film thickness Mode Profiles2. Titanium in-diffusion time and temperature Mode Profiles3. SiO2 strain film thickness and deposition temperature Strain field
Conversion Mechanism (index modulation) Static strain-optic (elastooptic) effect
Conversion EfficiencyUniform Grating ( 500 spatial periods)
• 1250 Å Ti film deposition• Photolithography to define Waveguides (Ti-strips)• 13 h diffusion @ 1035
oC and wet atmosphere
• 1.7 m SiO2 strain film deposited @ 389 oC
• Photolithography to define strain grating (500 periods) @ room temperature
After many trials:
Conversion EfficiencyTemperature Tuning (Uniform Grating)
1524 1526 1528 1530 1532 1534 1536 1538 1540 1542 1544 1546 15480.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
24.5 oC 22.5 oC 20.0 oC
17.7 oC 16.6 oC 15.2 oC
14.4 oC
Temperature tuning
Pol
ariz
atio
n C
onve
rison
Effi
cien
cy
Wavelength (nm)14 16 18 20 22 24 26
1528
1530
1532
1534
1536
1538
1540
1542
1544
Peak wavelengths vs Temperatureand
Linear Regression
d/dT = - 1.3419 nm / oC
Co
nve
rte
d P
ea
k w
ave
len
gth
(n
m)
Temperature (oC)
Sparse Grating:
L1L2 L3 L4 L5 L6
L L L LL LiNbO3
Ti diffused Waveguide
x y
z
Sparse Grating:Propagation Matrix
inTE
inTMLnn
cj
outTE
outTM
E
EeE
E gTEgTM
10
0
inTE
inTM
outTE
outTM
E
Ez
E
E
10
01
Combining Effects (Coupling and Propagation)
inTE
inTM
R
R
inTE
inTMnn
outTE
outTM
E
E
zAzjB
zjBzA
E
EPCPCPPCC
E
E
)()(
)()(121
c
nnLT gTMgTE )(
Tjez
Z Transform
s-plane
j
sTez
z-plane
)Re(z
1
)Im(z
s-plane
j
j
sTez
z-plane
)Re(z
1
)Im(z
Z Transform
n
ii zzzP
1
1)1()(
-1 -0.5 0 0.5 1
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Roots of B5(z)
Re(z)
Im(z
)
Filter Theoretical Frequency Response
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 70.0
0.2
0.4
0.6
0.8
1.0
Pol
ariz
atio
n C
onve
rsio
n E
ffici
ency
Normalized Frequency (-0) X 100 GHz)
FSR
DWDM Channels
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
0.0
0.2
0.4
0.6
0.8
1.0+6-6 -5 -4 -3 -2 -1 +10 +3+2 +5+4
Am
plitu
de (
a.u.
)
Normalized Frequency (-0) X 100 GHz)
Filtered DWDM Channels
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 70.0
0.2
0.4
0.6
0.8
1.0-6 +60
Am
plitu
de (
a.u.
)
Normalized Frequency ((-0) X 100 GHz)
Filter Theoretical Frequency Response
-4 -3 -2 -1 0 1 2 3 40.0
0.2
0.4
0.6
0.8
1.0P
olar
izat
ion
Con
vers
ion
Effi
cien
cy
Normalized Frequency ((-v0)/FSR)
Electrooptically Tunable Sparse Grating Filter
L1 L2 L3 L4 L5 L6
L L L LL LiNbO3
Ti diffused Waveguide
x y
z
Electrodes
L1 L2 L3 L4 L5 L6
L L L LL LiNbO3
Ti diffused Waveguide
x y
z
L1 L2 L3 L4 L5 L6
L L L LL LiNbO3
Ti diffused Waveguide
x y
z
Electrodes
Device Fabrication / Electrodes
Fabrication StepsTitanium Deposition
(DC sputtering)
LiNbO3
Ti t Patterning(Litho and Etching)
DiffusionLiNbO3
Ti t
LiNbO3
Ti
LiNbO3
Heatand Time
LiNbO3
Photolithography(Image Reversal)
E-Beam3 metalsLiNbO3
Lift-OffLiNbO3
Silica Deposition(E-beam evaporation)
@ High Temp
Cool-down toRoom Temp.
Surface Strainbuild-up
SiO2 < LiNbO3
Patterning(Litho and Etching)LiNbO3
SiO2
LiNbO3
SiO2
LiNbO3
SiO2
Device Fabrication / Electrodes
(Side view) LiNbO3
SiO2
SiO2 SiO2 SiO2
Electrodes
Conversion EfficiencyTest Setup
Er+ doped fiber
Laser DiodePump @ 980 nm
OSA
Sample under test
Objective
WDM 980/1550coupler
PZ fiber
Objective
Polarizer
Amplified Spontaneous Emission light source
Isolator
Conversion EfficiencyTest Results (Sparse Grating)
TE TE
TE TM TM TE
TM TM
Conversion EfficiencyTest Results (Sparse Grating)
) 9.131( 044.13 GHznmdB
1515 1518 1521 1524 1527 1530 1533 1536 1539 1542-30
-28
-26
-24
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
TE input/TM output T= 25.0 oC
TM input/TE output Theoretical Response
Pol
ariz
atio
n C
onve
rsio
n E
ffici
ency
(dB
)
Wavelength (nm)
%96PCE
Test Results (Sparse Grating)Thermal Tuning
1515 1520 1525 1530 1535 1540 1545 1550 15550.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
14oC
25oC
Po
lari
zatio
n C
on
vers
ion
Effi
cie
ncy
Wavelength (nm)
12 14 16 18 20 22 24 26 28 301524
1526
1528
1530
1532
1534
1536
1538
1540
1542
TM to TE conversion TM to TE data linear regression TE to TM conversion TE to TM data linear regression
Ce
nte
r P
ea
k W
ave
len
gth
(n
m)
Temperature (oC)
CdTd onm/ 0.1
Test Results (Sparse Grating)Voltage Tuning
input) (TM nm/V 045.0dVd
1520 1530 15400.0
0.2
0.4
0.6
0.8
1.070 V
-70 V
Pol
ari
zatio
n C
on
vers
ion
Effi
cie
ncy
Wavelength (nm)
-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
TM input/TE output Linear fit TM input data TE input/TM output Linear fit TE input data
Wa
vele
ng
th (
nm
)
Applied Voltage (V)
input) (TE nm/V 039.0dVd99.4%91.7%
Polarization Independent Sparse Grating Filter
InputInput
No Output
...
...
2
2
......
......
2
2
InputInputOutput
2
Polarization Independent Sparse Grating Filter
Polarization Independent Sparse Grating
L1 L2 L3
L L L L L
L3 L2 L1
LiNbO32
L1 L2 L3
L L L L L
L3 L2 L1
LiNbO3
L1 L2 L3
L L L L L
L3 L2 L1
LiNbO32
Test Results - Polarization Independent Sparse Grating
Er+ doped fiberLaser DiodePump @ 980 nm
WDM 980/1550coupler
Er ASE light source
PZ fiberOpticalPowerMeter
Ge PhotodetectorSampleUnder Test
CurrentSource
Output Fiber
Isolator
Er+ doped fiberLaser DiodePump @ 980 nm
WDM 980/1550coupler
Er ASE light source
PZ fiberOpticalPowerMeter
Ge PhotodetectorSampleUnder Test
CurrentSource
Output Fiber
Isolator
Test Results - Polarization Independent Sparse Grating
Test Results - Polarization Independent Sparse Grating
1518 1521 1524 1527 1530 1533 1536 1539 1542-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
TM input TE input Theoretical Response
No
rma
lize
d O
utp
ut S
pe
ctru
m (
dB
)
Wavelength (nm)
Test Results - Polarization Independent Sparse GratingThermal Tuning
1515 1520 1525 1530 1535 1540 1545 1550 15550.0
0.2
0.4
0.6
0.8
1.0
TE input @ 14oC
TE input @ 27oC
No
rma
lize
d F
ilte
r R
esp
onse
Wavelength (nm)
10 12 14 16 18 20 22 24 26 28 301524
1526
1528
1530
1532
1534
1536
1538
1540
1542
1544 TM input Linear Fit of TM data TE input Linear Fit of TE data
Wav
elen
gth
(nm
)
Temperature (oC)
CdTd onm/ 0.1
Future Work
• 4-Port Asymmetric MZI
L1 L2 L3
L L L L L
L3 L2 L1
LiNbO32
L1 L2 L3
L L L L L
L3 L2 L1
LiNbO32
Future Work
• Generic “all-zero” synthesis
L1 L2 L3 L4 L5 L6
B C D EA LiNbO3
Ti diffused Waveguide
x y
z
Electrodes
L1 L2 L3 L4 L5 L6
B C D EA LiNbO3
Ti diffused Waveguide
x y
z
L1 L2 L3 L4 L5 L6
B C D EA LiNbO3
Ti diffused Waveguide
x y
z
Electrodes
