Organic Nonlinear Optical Devices and Integrated Optics - PowerPoint PPT Presentation

View by Category
About This Presentation
Title:

Organic Nonlinear Optical Devices and Integrated Optics

Description:

... Optical Second-Harmonic Generation by Quasi-Phase Matching in Channel ... Times New Roman Symbol Projekt domy lny Microsoft Equation 3.0 Organic ... – PowerPoint PPT presentation

Number of Views:345
Avg rating:3.0/5.0
Slides: 52
Provided by: TungWahFr
Learn more at: http://www.forinpol.pl
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Organic Nonlinear Optical Devices and Integrated Optics


1
Organic Nonlinear Optical Devices and Integrated
Optics
2
Outline
  • Directional Coupler
  • Nonlinear Fabry-Perot Interferometer
  • Frequency Converter
  • Optical Limiter
  • Integrated Optics
  • Conclusions

3
Signal Switching IDirectional Coupler
4
Directional Coupler
  • Interaction length and refractive index
    difference of the cores control the splitting
    ratio

5
Fluorine doped polyimide
  • Fluorine content controls the refractive index of
    polyimide
  • Core and cladding layer can be made from the same
    polymer---polyimide.

6
Fabrication
mask
  • To make multi-layer patterned structure, only
    need spin coating, photolithography and RIE

7
Nonlinear directional coupler
  • Refractive index changes with light intensity
  • Splitting ratio changes with light intensity

8
Material requirement
  • Low switching power High n2 , ?(2)
  • Fast switching Low response time
  • Low propagation loss Low absorption
  • High optical damage threshold
  • High thermal stability

9
A candidate DPOP-PPV
  • A side chain substituted PPV
  • Loss 0.4 dB/cm at 920 nm
  • n2 1.1e-14 cm2/W
  • Imax gt 16 GW/cm2
  • Tg 163?C

10
Experimental Result
Waveguide 2
Waveguide 1
  • Length 1/3 beat length (0.67 cm)
  • Switching at 5.5 GW/cm2

11
Advantages and applications
  • Advantages
  • All optical switching
  • Bar state splitting 90/10
  • Cross state splitting 33/67
  • Polymer Easy processing
  • Applications
  • Beam splitter, Wavelength Add-Drop Multiplexer,
    Cross/Bar Switch

12
Signal Switching IIFabry-Perot Interferometer
13
Nonlinear Fabry-Perot Device
Signal In
Signal Out
Pump
Mirrors Reflectivity gt 95
Nonlinear medium
  • A wavelength selective device
  • Wavelength of the output signal depends on
    refractive index of the middle medium

14
Operation
  • Nonlinear middle medium poly-1,6-dicarbazoly
    1-2,4-hexadyne (DCHC)
  • Signal range 700 - 900 nm
  • Pump range 637 - 645 nm
  • Pump light changes the index of the middle medium
    and changes the wavelength selection at the
    output.

15
Experimental Results
16
Performance
  • Pump 2 GW/cm2 at 641 nm for 0.8 ps
  • Turn on time 0.33 ps
  • Recovery time 3 ps
  • Can switch at 333 GHz
  • All optical switching
  • Very simple structure, easy processing

17
Frequency ConversionSecond Harmonic Generation
Device
  • A waveguide-type with periodic structure

18
Waveguide-type periodic structure
  • Waveguide-type compact, easy coupling to
    fibre/laser
  • Periodic alternations of nonlinearities in the
    waveguide enable phase-matching for light at ?
    and 2?.
  • Conversion

19
Periodic structure
Linear material
Nonlinear material
20
Organic crystal Semiconductor
  • Nonlinear material mNA (organic crystal grown on
    the grating)
  • Linear material SiN (grating)

21
Performance
?(2) 2d33
  • mNA d33 20 pm/V
  • Period 7 ?m
  • Length 5 mm
  • Wavelength 1.06 ?m
  • Conversion efficiency 0.16 /W/cm2

22
An all-polymer one
  • Nonlinear polymer diazo-dye-substituted
  • Linear polymer UV curable epoxy resin

23
Fabrication
  • Serial grafting technique

Photolithography
RIE
24
Experimental Results
  • The nonlinear polymer d33 15 pm/V (after
    poled at 35 MV/m at 140?C)
  • Loss 1.2 dB/cm
  • Period 32 ?m
  • Wavelength 1550 nm
  • Conversion efficiency 0.5/W/cm2

25
Signal ProcessingOptical Limiter
26
Operation of Optical Limiter
  • Low fluence Linear transmittance
  • High fluence Clamped output level

27
Reverse saturable absorption
  • Low intensity Molecule is in low absorption
    state. Linear transmittance
  • High intensity Molecule is in photoinduced
    absorbing state. The material becomes highly
    absorptive.
  • Candidate material
  • Metallo-Phthalocyanines
  • Fullerenes

28
Metallo-Phthalocyanines
  • Very weak ground state absorption
  • Strong excited state absorption

29
Experimental Results
C60 in toluene
AlClPc in methanol
InClPc in toluene
  • Length 1 cm
  • Wavelength 532 nm
  • Pulse width 8 ns

30
Fullerenes (Bucky balls)
  • All-carbon cluster
  • Abundance of CC gives plenty delocalizeable
    electrons
  • C60, C70, C 76, ...

31
Experimental Results
  • Solvent used plays an important role

32
Linear NonlinearIntegrated Optics
33
Advantages of polymer
  • Low loss 0.1 dB/cm at 1550 nm
  • Controllable nonlinearities by doping/poling
  • Low cost only need spin-coating,
    photolithography and RIE
  • Mechanical properties rugged, flexible
  • Precise control of refractive index conveniently
    done by doping
  • Convenient thickness control spin-coating

34
Example 1 All polymer waveguide and MZ
  • All polymer 3-D structures
  • Achieve multi-level interconnections

35
Material
  • UV15LV low loss polymer as waveguide
  • Polyurethane with tricyano chromophores Active
    polymer with electro-optic coefficient r33 12
    pm/V
  • Waveguide loss 0.5 dB/cm

36
Phase modulator
  • Upper level EO modulator
  • Lower level waveguide

37
Example 2 Optical Transceiver
38
Characteristics
  • Integrate polymer waveguide into semiconductor
    system
  • Use polymer for waveguide and splitter
  • Easy fabrication of polymer Y-branch structure

39
Example 3 Laser array and beam combiner
Laser array
Polymer beam combiner
40
Material
Polymer waveguide
The polymers are spin-coated on the
laser-array-existing semiconductor substrate
41
Features and applications
  • Loss lt 1 dB/cm
  • Good polymer adhesion to the substrate
  • Applications
  • Wavelength multiplexer/demultiplexer
  • MW-O-CDMA transmitter

42
Conclusions
  • Polymers are good for
  • waveguide structure low loss
  • EO or nonlinear operation high and controllable
    nonlinearities
  • Multi-level structure (3D) result of easy
    processing
  • Hybrid semiconductor/polymer structures or all
    polymer structures give rise to ample
    opportunities

43
Reference 1
  • Polymer Directional Coupler
  • J. Kobayashi et al., Directional Couplers Using
    Fluorinated Polyimide Waveguides, Journal of
    Lightwave Technology, Vol.16, No. 4, pp. 610-613,
    1998.
  • T. Gabler et al., Application of the
    polyconjugated main chain polymer DPOP-PPV for
    ultrafast all-optical switching in a nonlinear
    directional coupler, Journal of Chemical
    Physics, Vol. 245, pp. 507-516, 1999.
  • Polymer Fabry-Perot Device
  • M. Bakarezos et al., Ultrafast nonlinear
    refraction in an integrated Fabry-Perot etalon
    containing polydiacetylene, Proc. CLEO 99,
    CWF12, pp. 258, 1999.

44
Reference 2
  • Polymer waveguide second harmonic generation
    devices
  • T. Suhara et al., Optical Second-Harmonic
    Generation by Quasi-Phase Matching in Channel
    Waveguide Structure Using Organic Molecular
    Crystal, IEEE Photonic Technology Letters, Vol.
    5, No. 8, pp. 934-936, 1993.
  • Y. Shuto et al., Quasi-Phase Matched
    Second-Harmonic Generation in Diazo-Dye-Substitued
    Polymer Channel Waveguides, IEEE Journal of
    Quantum Electronics, Vol. 33, No. 3 pp. 349-357,
    1997.
  • Optical limiter
  • Y. Sun et al., Organic and inorganic optical
    limiting materials. From fullerenes to
    nanoparticles, International Reviews in Physical
    Chemistry, Vol. 18, No. 1, pp. 43-90, 1999.
  • Integrated Optics
  • S. M. Garner et al., Three-Dimensional
    Integrated Optics Using Polymers, IEEE Journal
    of Quantum Electronics, Vol. 35, No. 8 pp.
    1146-1155, 1999.
  • N. Bouadma et al., Monolithic Integration of a
    Laser Diode with a Polymer-Based Waveguide for
    Photonic Integrated Circuits, 1994.
  • T. Ido et al., A simple low-cost polymer PLC
    platform for hybrid integrated transceiver
    modules, 2000

45
Appendix A
46
Semiconductor NLDC
  • Based on MQW SC laser
  • Operate at the transparency point

47
Properties
  • Good nonlinearity
  • Fast response
  • Lower switching power
  • Complicated structure (e.g. MQW)
  • Need current injection (120 mA)
  • Loss 25 dB/cm at 879 nm

48
Other SC structures
  • Villenevue, 1992
  • no current injection is required
  • still need MQW
  • splitting ratio and switching power are
    comparable to the nonlinear polymer ones.
  • Semiconductor Directional coupler
  • S. G. Lee et al., Subpicosecond switching in a
    current injected GaAs/AlGaAs multiple-quantum-well
    nonlinear directional coupler, Applied Physics
    Letters,Vol. 64, pp. 454-456, 1994.
  • A. Villeneuve et al., Ultrafast all-optical
    switching in semiconductor nonlinear directional
    couplers at half the band gap, Applied Physics
    Letters, Vol. 61, pp. 147-149, 1992.

49
Appendix B
50
Carrier generation through nonlinear optical
process
  • Direct bandgap material
  • 2PA
  • intensity dependent effective for ultrashort
    pulse (ps to sub-ps)
  • Indirect bandgap material
  • linear indirect absorption
  • fluence dependent good for ps to 100s ns

51
Experimental Results
Si
GaAs
  • Pulse width 25 ps, wavelength 1060 nm
About PowerShow.com