MackGraphe is a new research center at Mackenzie Presbyterian University dedicated to investigating the properties of graphene and other nanomaterials with an applied engineering perspective. The center initiated activities in 2012 with a focus on graphene synthesis, characterization, and photonic device development. Previous work included functionalizing optical fiber tips with carbon nanotubes for mode-locked fiber lasers and depositing polymer films inside hollow-core photonic crystal fibers. Current research interests include exploiting graphene's saturable absorption, nonlinearity, and plasmonic properties for all-integrated photonic devices based on nonlinear and plasmonic effects.

1. Guided nanophotonic devices and
applications
Christiano J. S. de Matos
MackGraphe - Graphene and Nano-Materials Research Center
Mackenzie Presbyterian University
http://www.mackenzie.br/mackgrafe.html
cjsdematos@mackenzie.br

2. • MackGraphe
• Previous work
– Fibers with coated/functionalized surfaces
– Plasmonic and nonlinear waveguides
• Current research focus and interests
• Acknowledgments
Outline
2

3. Mackenzie

4. • A brand new research center
dedicated to the investigation of
the properties of graphene and
other nano-materials with
an applied engineering
thinking.
4
MackGraphe
• Strong
collaboration
with the
industry
expected

5. Start up funding
5
MackGraphe
Fapesp : US$ 5.000.000,00.
Instituto Presbiteriano Mackenzie:
US$ 10.000.000,00.
MackPesquisa: US$ 400.000,00
CNPq: US$ 400.000,00

6. Eunézio
A
de
Souza
(Thoroh)
Christiano
J.S.
de
Matos
Juan
Alfredo
Guevara
Carrió
Guilhermino
Fachine
Mauro
Terence
Leila
Figueiredo
de
Miranda
Jairo
José
Pedrotti
Anamaria
Dias
Pereira
Alexiou
Maura
Vincenza
Rossi
Antonio
Helio
de
Castro
Neto
(Visiting
Professor)
Chemistry
Materials
Engineering
Electric Eng. and
Physics
Visiting Professor
Dario Bahamon
Hugo L. Fragnito
UNICAMP
External professor
Lucia Saito
6
MackGraphe’s Faculty
Sergio
Domingues

7. • MackGraphe initiated its activities in 2012, with
the aim to carry out graphene synthesis,
characterization, and device development, with
special attention to photonic devices.
7
MackGraphe

8. Previous work
8

9. Fibers with coated/functionalized
surfaces

10. Fiber tips with carbon
nanotube films
10
• Mode locking fiber lasers with C nanotube
saturable absorbers extensively studied
• A micropipette was used to deposit a polymer
film containing nanotubes
20 µm thickness achieved

11. 11
• Mode-locked laser design and film
optimization
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
1
2
3
4
5
6
7
8
9
10
11
αL product
Bandwidth(nm)
(a)
Erbium-doped fiber
Polarization
controller
WDM
coupler
Signal
Isolator
24% output
coupler
CNT Saturable
absorber sample
R. M. Gerosa et al., IEEE Photon. Technol. Lett. 25, 1007 (2013)
Fiber tips with carbon
nanotube films

12. 12
• Mode-locked fiber laser characterization
1540 1545 1550 1555 1560 1565 1570
0.0
0.2
0.4
0.6
0.8
1.0
1.2
NormalizedIntensity
Wavelength (nm)
ΔλFWHM
= 10.2 nm
-2 -1 0 1 2
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
NormalizedIntensity
Time delay (ps)
actual pulsewidth
= 364 fs
Fiber tips with carbon
nanotube films
R. M. Gerosa et al., IEEE Photon. Technol. Lett. 25, 1007 (2013)

13. 13
• Layer-by-layer electrostatic deposition
PAH (+)
Congo
red (-)
32-nm thick polymer film deposited
by layer-by-layer method (4 Congo
Red/PAH bilayers)
R. E. P. de Oliveira et al., JOSA B, 2012
Polymer-coated inner walls

14. Polymer-coated inner walls
• Modes guided by anti-resonance in a hollow-
core PCF
600 620 640 660 680 700 720 740 760 780 800
-30
-20
-10
0
NormalizedTransmission(dB)
Wavelength (nm)
14
R. E. P. de Oliveira et al., JOSA B, 2012

15. Plasmonic and nonlinear
optical waveguides
15

16. Electrically-controlled phase-matched
frequency conversion in a microring
• Frequency conversion via four-wave mixing (3rd
order NL effect) in microressonators is actively
studied nowadays
• The application of a DC field enables second-
harmonic or sum/difference freq. generation (2nd
order NL effect)
• However, phase-matching is required for efficient
conversion
16

17. Electrically-controlled phase-matched
frequency conversion in a microring
• Here: quasi-phase-matched second harmonic
generation is numerically obtained in a silicon
nitride microring ressonator
17!
!

18. Electrically-controlled phase-matched
frequency conversion in a microring
• Unlike with four wave mixing, frequency
conversion can be actively switched on and off
18!

19. Preform with gold nanoparticles
Plasmon excitation in optical fibers
containing gold nanoparticles
• A fiber has been fabricated containing gold ions
• Gold nanoparticle nucleation is induced by heating
• Absorption due to plasmon resonance can be
observed and can be exploited for nonlinear
optical devices
19
Before nucleation
After nucleation

20. Plasmon excitation in optical fibers
containing gold nanoparticles
• Mach-Zehnder Interferometer
• Cross-phase modulation: 1550 nm signal and
660nm resonant pump (10 mW CW)
• Thermal response (µs response time)
201546 1548 1550 1552 1554
-87
-86
-85
-84
-83
-82
-81
dBm
Wavelength [nm]
n2 = 7x10-15 m²/W

21. Current focus and interests
21
All-waveguide integrated devices based on
nonlinear and plasmonic effects in graphene and
graphene-like materials

22. Graphene assets for
photonic applications
22
• Highly transparent (97.3 % transmission) while
highly absorptive
• Absorption is saturable
• Flat broadband absorption can be electrically
switched off
• Highly nonlinear (n2 ~ 108 times higher than
that of silica)
• Promising plasmonic properties (high carrier
mobility)

23. Current projects and interests
• Four wave mixing in graphene on the tip of a fiber
23
B. Xu et al., IEEE Photon. Technol. Lett. 24, 1792 (2012)
1000 1050 1100 1150
-70
-60
-50
-40
-30
-20
-10
0
Com grafeno
Sem grafeno
Potêncianormalizada(dB)
Comprimento de onda (nm)
6,8 dB

24. Current projects and interests
• Saturable absorption, nonlinear optics and
plasmonics in graphene next to a waveguide
24
W. Li et al., Nano Lett. 14, 955 (2014)

25. Acknowledgments
• Team @ Mackgraphe
– Ivan Hernandez Romano
– Daniel Lopez Cortes
– Rafael E. P. de Oliveira
– Rodrigo M. Gerosa
– Tamiris G. Suarez
– Priscila Romagnoli
– Paulo Justino
– Charles Miranda
– Robson A. Colares
– Gerson Kazumi Sinohara
– Julio Freitas
25
• Main Collaborators
– Prof. Walter Margulis
(ACREO-Sweden)
– Prof. Michael Fokine
(KTH-Sweden)
– Prof. F. Lazaro Freire
(PUC-Rio – Brazil)
– Prof. A. H. Castro Neto
(NUS – Singapore)
– Prof. Marcos A. Pimenta
(UFMG – Brazil)
– Prof. Gustavo Wiederhecker
(Unicamp – Brazil)
• Financial support: FAPESP, CNPq, FINEP, Mackpesquisa