POLED SOL-GEL MATERIALS DOPED WITH PUSH-PULL CHROMOPHORES: NMP1-FP6 project

The aim of the ODEON project is the development of innovative multifunctional nano-materials for optoelectronic devices. The research has been carried out by design, synthesis and fabrication of a demonstrator of an interferometric electro-optical modulator (Mach-Zender).

Giovanna Brusatin, Gioia Della Giustina, Massimo GuglielmiDepartment of Mechanical Engineering– Materials Sector, University of PadovaMauro Casalboni, Fabio De MatteisDipartimento di Fisica, Università di Roma "Tor Vergata“Massimiliano Dispenza, Anna Maria Fiorello, Mauro VarasiSELEX S.I., Roma - Finmeccanica – RomaSigurd Schrader, Bernd GrimmUniversity of Applied Sciences Wildau Engineering Physics Wildau

Control Voltage Vc

Electro-optic waveguide

Optical data pulses

Constant light input

Push-Pull Chromophores: Molecular hyperpolarizability (induced dipole moment by an external electric field) p=E+EE+EEE+…

Random orientation: cancellation of single contribution χ(2) = 0

Doping of hybrids sol-gel or polymer matrices

Electro-Optical modulator: Oriented NL push pull organic dyes in hybrids sol-gel or polymer matrices

Electric poling: the isolated molecule properties are transferred to the macroscopic materials

Oriented dipoles: single contributions added as vectors χ(2)

≠ 0

Electro-optic waveguide

Optical data pulses

light input

Control Voltage Vc

Lithographic process of active films: channel waveguides

Chromophores, Sol-gel precursors and Hybrid sol gel doped films

Chromophore: UAS HD-02

N

NO2N

N

CH3

O

O

N

OH

Spacer: CbOH

-The codoping with N-hydroxyethylcarbazole, CbOH, as physical spacer avoids dye aggregation-The covalent link of the chromophore by the epoxy-amino coupling reaction.

Epoxy-amino coupling reaction

N

NO2N

N

CH3

O

O

Sol gel process

Films processes: Pretreatment and Poling

SH signal

Laser input

Horizontal corona poling at high T (~300°C); In situ SHG measure= 1368nm or 1600nm

Example of NL coefficient measure and of the time stability of chromophore orientation in sol

gel matrices; d33 ~ 11pm/V

0 20 40 60 80 100 120 140 1600.0

0.2

0.4

0.6

0.8

1.0

no

rmal

ized

d33

time (days)

Films processes: Pretreatment and Poling

300 400 500 600 700 8000.0

0.5

1.0

1.5

2.0

before baking before poling-after baking

2h 90°C under vacuum after poling

2h 90°C + 2h 120°C 6kV in N

2

ab

so

rba

nc

e

wavelength (nm)

Monitoring of the UAS HD-02 UV-vis absorption during thermal treatment in vacuum and poling in N2- absorption remains intense at 120°C and after poling- CbOH is partially removed during the prebaking in vacuum and is totally removed after poling- under the electric field the inorganic crosslinking is completed- the thermal treatment produce a further organic condensation between epoxy and amine- the presence of amine determine basic catalysis of the sol and protection against photobleaching

90°C + 120°C 4h 90°C + 120°C 4h ++

PolingPoling

Large time stability of cromophoresorientation

Lithographic process for a Y-shaped waveguide

SEM microscopy images of a Y-branched waveguide patterned by traditional lithographic process (using RIE) on doped sol gel films

Light injection and light confinement by an Y-shaped optical fiber produced by direct patterning

Electro-optic waveguide

Optical data pulses

light input

Control Voltage Vc

SOL-GEL NL FILM SOL-GEL NL FILM

ODEON PARTNERSINS: INSTM – FirenzeUniversity of Padova, Department of Engineering and Chemistry, Giovanna Brusatin, Massimo Guglielmi, Danilo Pedron, Renato BozioUniversity of Milano Bicocca: Giorgio A. Pagani, Alessandro Abbotto, Luca BeverinaUniversity of Napoli, Department of Chemistry, Antonio Roviello, Roberto CentoreC.N.R. of Firenze, IFAC – Applied Physics Institute: Emilia Giorgetti, Stefano SottiniUniversity of Sassari, Department of Architecture and Planning, Plinio InnocenziUTV: NeMO - Dip. di Fisica Università di Roma – Tor Vergata, Mauro CasalboniENS: ENS Lyon, Chantal AndrauENG: CNRS and University of Strasbourg, Alain Fort UHA: Hamburg University Department of Chemistry Martin-Luther, Jürgen HeckUKA: Physikalische Chemie Universitaet Kaiserslautern, Hans-Georg Kuball, Graziano ArchettiUAS: University of Applied Sciences Wildau Engineering Physics , Sigurd SchraderAMS: SELEX, Alenia Marconi Systems, Annamaria Fiorello, Massimiliano Dispenza, Mauro VarasiWEI: Weizmann Institute of Science, Dep. of Organic Chemistry, Israel M. E. van der Boom CEA: CEA-SACLAY DRT-LITEN DTS/CS, Lionel Sicot, Dr. Pierre-Alain Chollet ULP: IPCMS-GONLO Alain FortKTH: Theoretical Chemistry Royal Institute of Technology, Stockholm , Hans Agren

POLED SOL-GEL MATERIALS DOPED WITH PUSH-PULL CHROMOPHORES: NMP1-FP6 project