Coherent-Coupling-Based Wide-Angle Optical Polarization Splitter

1
Coherent-Coupling-Based Wide-Angle Optical
Polarization Splitter

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Outline

• Introduction
• Principle of Operation
• Process Steps and Results
• Future Work
• References

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• Introduction
• Principle of Operation
• Process Steps and Results
• Future Work
• References

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Polarization Splitter

• Motivation
• TE and TM mode have different electrooptic
  coefficients in birefringence material.
• Principle Mode interference
• Mode sorting
• Structure Directional coupler type
• Y-branch type
• Material Ti Ni PE APE Zn / Ni
• In my work
• Structure Y-branch type (simplified coherent
  couple)
• Material Zn / Ni

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• Introduction
• Principle of Operation
• Process Steps and Results
• Future Work
• References

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Principle of Operation

• Vary the length L can
• make TM mode coupled to another waveguide.

(a) Directional coupler type

• Curved bend
• Chamfered bend
• Prism-assisted bend
• Substrate prism bend
• Coherently-coupled bend

(b) Y-branch type
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Coherently Coupler Bend
(a)standard structure
(b)new structure
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Polarization Splitter
Coherently-coupled Bend (S-band)

• With a suitable coupling length, TM wave can be
  coupled to the S-band but not TE wave .

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• Introduction
• Principle of Operation
• Process Steps and Results
• Future Work
• References

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Process Steps
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Coherently-Coupled Y-branch Waveguide
W

• L1 L215 / tan (0.5)
• L2 coupling length
• L3 1000µm
• W 6µm

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Process Parameters
For TM Mode
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TM Mode Power Splitter
TM
2.2 ?W
Laser Wavelength 1.55?m Pumping Current 45
mA Coherent Length 350 ?m
0.42 ?W
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Straight Waveguide
TM mode
2.2 ?W
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S-band Waveguide
TM mode Coupling Length 350 ?m
0.42 ?W
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• Introduction
• Principle of Operation
• Process Steps and Results
• Future Work
• References

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Future Work

• Vary the coupling length to make sure if 350 ?m
  is the best coupling length.
• We have mask for the coupling lengths 400
  ?m, 450 ?m, 500 ?m, and 550 ?m.
• When the best one is obtained, a new mask is
  required for the proposed polarization splitter.

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References

• Ruey-Ching Twu, Chia-Chih Huang and Way-Seen Wang
  TE-TM Mode Splitter With Heterogeneously Coupled
  Ti-Diffused And Ni-Diffused Waveguides On Z-cut
  Lithium Niobate,Electron. Lett., 3rd, vol. 36,
  no. 3, pp. 220-221, Feb. 2000.
• Jiun-Yun Li, Wen-Hao Hsu, and Way-Seen Wang,
  Member, IEEE A TH-TM Mode Splitter Using
  Annealed Proton Exchange And Zinc/Nickel
  Co-Diffusion Waveguides
• J.J. Su and W. S. Wang, Novel coherently-coupled
  multi-sectional bending optical waveguide,
  Photo.Tech. Letters, August 2002.