Trends in Future CommunicationsInternational Workshop - Renato Rabelo

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Trends in Future CommunicationsInternational Workshop - Renato Rabelo

  1. 1. Trends in Future Communications International Workshop CPqD - Campinas Renato Cunha Rabelo, PhD – IEAv-DCTA 24/02/2014
  2. 2. Outline • IEAv/DCTA • Lithium Niobate Filters
  3. 3. IEAv EAH ENU EFA EFO ESTEGI
  4. 4. IEAv EAH ENU EFA EFO ESTEGI Institute for Advanced Studies
  5. 5. IEAv EAH ENU EFA EFO ESTEGI Institute for Advanced Studies Mission: Build scientific knowledge and develop strategic technology capable of strengthening Brazilian aerospace competence.
  6. 6. IEAv EAH ENU EFA EFO ESTEGI Photonics Division
  7. 7. IEAv EAH ENU EFA EFO ESTEGI Photonics Division Generate, control and detect light
  8. 8. IEAv EAH ENU EFA EFO ESTEGI EFO-LEFO-SEFO-O
  9. 9. PhDs Masters Graduates Technician s 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
  10. 10. Collaborators Postdocs MSc / PhD Students Graduates / MSc Students Undergrad Students EFO-L 01 10 04 06 EFO-O 1 0 0 10 EFO-S 02 0 2 02 Total EFO 04 10 06 18 38
  11. 11. Spectral Slicing Filters in Titanium Diffused Lithium Niobate (Ti:LiNbO3) Waveguides
  12. 12. WDM Fiber Optic Communication link λ1ReceiverTransmitterλ1 Optical Fiber Transmitterλ2 Transmitterλn-1 Transmitterλn λ2Receiver λn-1Receiver λnReceiver .. . .. . MUX DEMUX
  13. 13. 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+4Amplitude(a.u.) Normalized Frequency (ν-ν0 ) X 100 GHz)
  14. 14. TE-TM Mode Conversion: LiNbO3 Ti diffused Waveguide xˆ yˆ zˆ TE TM L SiO2 Strain inducing grating Λ
  15. 15. TE-TM Mode Conversion: unconvconv conv PP P PCE + =                         ∆ −       ∆ + =      ∆∆ ∆−∆− )0( )0( sin 2 cossin sinsin 2 cos )( )( 2/2/ 2/2/ B A yjyeyje yjeyjye yB yA yjyj yjyj δ δ δδ δ κ δ δ κ δ δ δ )()( 0 0 TMTETMTE nnnnv c − = − =Λ λ 0 2)(2 = Λ ± − =∆ ππ c nnv TMTE Λ ± − =∆ ππ 2)(2 c nnv TMTE             =      )0( )0( cossin sincos )( )( B A LLj LjL LB LA κκ κκ LL L κκ κ 22 2 cossin sin + = Lκ2 sin=
  16. 16. TE-TM Mode Conversion: -12 -8 -4 0 4 8 12 0.0 0.2 0.4 0.6 0.8 1.0PolarizationConversionEfficiency Normalized Frequency ((ν−ν0 ) x 100 GHz)
  17. 17. Fabrication Steps Titanium Deposition (DC sputtering) LiNbO3 Ti t Patterning (Photolithography) Diffusion LiNbO3 Ti t LiNbO3 Ti LiNbO3 Heat and Time LiNbO3 SiO2 Silica Deposition (E-beam evaporation) @ High Temp Cool-down to Room Temp.LiNbO3 SiO2 Surface Strain build-up αSiO2 < α LiNbO3 Patterning (Photolithography)LiNbO3 SiO2 (Side view) LiNbO3 SiO2SiO2SiO2SiO2 SiO2 SiO2 Λ
  18. 18. Conversion Efficiency Test Setup Er+ doped fiber Laser Diode Pump @ 980 nm OSA Sample under test Objective WDM 980/1550 coupler PZ fiber Objective Polarizer Amplified Spontaneous Emission light source Isolator
  19. 19. Conversion Efficiency Test Setup
  20. 20. Conversion Efficiency Test Results (Uniform Grating) TM → TM TM → TE TE → TE TE → TM
  21. 21. Conversion Efficiency Test Results (Uniform Grating) 22 2 )()( )( zBzA zB utputr at the oTotal powe ion powerpolarizatConverted PCE + == 1528 1530 1532 1534 1536 1538 1540 0.0 0.2 0.4 0.6 0.8 1.0 W/G 5 - Linear Scale Room Temperature 500 elements TE input/TM output TM input/TE output Theoretical Response PolarizationConversionEfficiency Wavelength (nm) Conversion Efficiency = 99.8% @ 1533 nm
  22. 22. Device Fabrication Conversion Efficiency •Coupling coefficient had to be adjusted dxdzEE TM pert TE ∫ ∞ ∞− ∆⋅= εκ Critical Parameters: 1. Titanium film thickness → Mode Profiles 2. Titanium in-diffusion time and temperature → Mode Profiles 3. SiO2 strain film thickness and deposition temperature → Strain field Conversion Mechanism (index modulation) → Static strain-optic (elastooptic) effect
  23. 23. Conversion Efficiency Uniform Grating ( 500 spatial periods) • 1250 Å Ti film deposition • Photolithography to define Waveguides (Ti-strips) • 13 h diffusion @ 1035 o C and wet atmosphere • 1.7 µm SiO2 strain film deposited @ 389 o C • Photolithography to define strain grating (500 periods) @ room temperature After many trials:
  24. 24. Conversion Efficiency Temperature Tuning (Uniform Grating) 1524 1526 1528 1530 1532 1534 1536 1538 1540 1542 1544 1546 1548 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 24.5 o C 22.5 o C 20.0 o C 17.7 o C 16.6 o C 15.2 o C 14.4 o C Temperature tuning PolarizationConverisonEfficiency Wavelength (nm) 14 16 18 20 22 24 26 1528 1530 1532 1534 1536 1538 1540 1542 1544 Peak wavelengths vs Temperature and Linear Regression dλ/dT = - 1.3419 nm / o C ConvertedPeakwavelength(nm) Temperature ( o C)
  25. 25. Sparse Grating: L1 L2 L3 L4 L5 L6 L L L LL LiNbO3 Ti diffused Waveguide xˆ yˆ zˆ
  26. 26. Sparse Grating: Propagation Matrix ( )               =      − − −− − − inTE inTM Lnn c j outTE outTM E Ee E E gTEgTM 10 0 ω               =      − − − − − inTE inTM outTE outTM E Ez E E 10 01 Combining Effects (Coupling and Propagation)               =      =      − − − − − − − inTE inTM R R inTE inTM nn outTE outTM E E zAzjB zjBzA E E PCPCPPCC E E )()( )()( 121  c nnL T gTMgTE )( − = Tj ez ω =
  27. 27. Z Transform s-plane z-planes-plane z-plane
  28. 28. Z Transform ∏= − −= n i i 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)
  29. 29. Filter Theoretical Frequency Response -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 PolarizationConversionEfficiency Normalized Frequency (ν-ν0 ) X 100 GHz) ∆νFSR
  30. 30. 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+4Amplitude(a.u.) Normalized Frequency (ν-ν0 ) X 100 GHz)
  31. 31. Filtered 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 +60 Amplitude(a.u.) Normalized Frequency ((ν-ν0 ) X 100 GHz)
  32. 32. Filter Theoretical Frequency Response -4 -3 -2 -1 0 1 2 3 4 0.0 0.2 0.4 0.6 0.8 1.0 PolarizationConversionEfficiency Normalized Frequency ((ν-v0 )/∆νFSR )
  33. 33. Electrooptically Tunable Sparse Grating Filter L1 L2 L3 L4 L5 L6 L L L LL LiNbO3 Ti diffused Waveguide Electrodes L1 L2 L3 L4 L5 L6 L L L LL LiNbO3 Ti diffused Waveguide L1 L2 L3 L4 L5 L6 L L L LL LiNbO3 Ti diffused Waveguide Electrodes
  34. 34. Device Fabrication / Electrodes Fabrication Steps Titanium Deposition (DC sputtering) LiNbO3 Ti t Patterning (Litho and Etching) Diffusion LiNbO3 Ti t LiNbO3 Ti LiNbO3 Heat and Time LiNbO3 Photolithography (Image Reversal) E-Beam 3 metalsLiNbO3 Lift-Off LiNbO3 Silica Deposition (E-beam evaporation) @ High Temp Cool-down to Room Temp. Surface Strain build-up αSiO2 < α LiNbO3 Patterning (Litho and Etching)LiNbO3 SiO2 LiNbO3 SiO2 LiNbO3 SiO2
  35. 35. Device Fabrication / Electrodes (Side view) LiNbO3 SiO2 Λ SiO2 SiO2 SiO2 Electrodes
  36. 36. Conversion Efficiency Test Setup Er+ doped fiber Laser Diode Pump @ 980 nm OSA Sample under test Objective WDM 980/1550 coupler PZ fiber Objective Polarizer Amplified Spontaneous Emission light source Isolator
  37. 37. Conversion Efficiency Test Results (Sparse Grating) TE → TE TE → TM TM → TE TM → TM
  38. 38. Conversion Efficiency Test Results (Sparse Grating) )9.131(044.13 GHznmdB =∆λ 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 o C TM input/TE output Theoretical Response PolarizationConversionEfficiency(dB) Wavelength (nm) %96≅PCE
  39. 39. Test Results (Sparse Grating) Thermal Tuning 1515 1520 1525 1530 1535 1540 1545 1550 1555 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 14 o C 25 o C PolarizationConversionEfficiency Wavelength (nm) 12 14 16 18 20 22 24 26 28 30 1524 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 CenterPeakWavelength(nm) Temperature ( o C) CdTd o nm/0.1−=λ
  40. 40. Test Results (Sparse Grating) Voltage Tuning input)(TMnm/V045.0=dVdλ 1520 1530 1540 0.0 0.2 0.4 0.6 0.8 1.0 70 V -70 V PolarizationConversionEfficiency 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 Wavelength(nm) Applied Voltage (V) input)(TEnm/V039.0=dVdλ 99.4%91.7%
  41. 41. Polarization Independent Sparse Grating Filter InputInput No Output πφ =∆
  42. 42. ... ... 2 Λ 2 Λ ...... ...... 2 Λ 2 Λ InputInput Output πφ 2=∆ Polarization Independent Sparse Grating Filter
  43. 43. Polarization Independent Sparse Grating L1 L2 L3 L L L L L L3 L2 L1 LiNbO3 L1 L2 L3 L L L L L L3 L2 L1 LiNbO3 L1 L2 L3 L L L L L L3 L2 L1 LiNbO3
  44. 44. Test Results - Polarization Independent Sparse Grating Er+ doped fiber Laser Diode Pump @ 980 nm WDM 980/1550 coupler Er ASE light source PZ fiber Optical Power Meter Ge Photodetector Sample Under Test Current Source Output Fiber Isolator Er+ doped fiber Laser Diode Pump @ 980 nm WDM 980/1550 coupler Er ASE light source PZ fiber Optical Power Meter Ge Photodetector Sample Under Test Current Source Output Fiber Isolator
  45. 45. Test Results - Polarization Independent Sparse Grating
  46. 46. 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 NormalizedOutputSpectrum(dB) Wavelength (nm)
  47. 47. Test Results - Polarization Independent Sparse Grating Thermal Tuning 1515 1520 1525 1530 1535 1540 1545 1550 1555 0.0 0.2 0.4 0.6 0.8 1.0 TE input @ 14 o C TE input @ 27 o C NormalizedFilterResponse Wavelength (nm) 10 12 14 16 18 20 22 24 26 28 30 1524 1526 1528 1530 1532 1534 1536 1538 1540 1542 1544 TM input Linear Fit of TM data TE input Linear Fit of TE data Wavelength(nm) Temperature ( o C) CdTd o nm/0.1−=λ
  48. 48. Future Work • 4-Port Asymmetric MZI L1 L2 L3 L L L L L L3 L2 L1 LiNbO3 L1 L2 L3 L L L L L L3 L2 L1 LiNbO3
  49. 49. Future Work • Generic “all-zero” synthesis L1 L2 L3 L4 L5 L6 B C D EA LiNbO3 Ti diffused Waveguide Electrodes L1 L2 L3 L4 L5 L6 B C D EA LiNbO3 Ti diffused Waveguide L1 L2 L3 L4 L5 L6 B C D EA LiNbO3 Ti diffused Waveguide Electrodes
  50. 50. Thank you ! rcrabelo@ieav.cta.br

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