This document summarizes research on X-junction polymeric optical switches. It discusses early work using lithium niobate that was later improved using polymers with higher thermo-optic coefficients. Several studies are summarized that experiment with different polymer materials like PMMA, exploring parameters like crosstalk, transmission characteristics, switching time, bandwidth, and power consumption. More recent work was able to achieve crosstalk less than -28dB, switching times of 1-2ms, and bandwidths over 200nm using various polymer cores and claddings in X-junction switch designs.

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By:
Hojjatollah Sarvari
Department of Electrical Engineering
Shiraz University, Shiraz-Iran
November-2008
X-Junction Polymeric Optical Switch

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INTRODUCTION
-- First X-DOS by Silberberg in 1987 with LiNbO3
-- Polymers have high thermo-optic coeffecient and low thermal
conductance
-- Important parameters of switches are:
Crosstalk
Transmision characteristic
Switching time
Bandwidth
Power consumption

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A NOVEL TYPE OF 2x2 DIGITAL OPTICAL SWITCH
REALIZED BY POLYMER WAVEGUIDE TECHNOLOGY
Norbert Keil, Huihai Yao, Crispin Zawadzki
22nd European Conference on Optical Communication - ECOC’96, Oslo
• PMMA (poly methyl methacrylate)
Refractive index is 1.5465
• θ<Δβ/Ɣ:
fundamental mode to waveguide with high n
first higher mode to waveguide with low n
• Β is difference propagation constants
• For θ=0.08 degree and λ=1.55um & λ=1.3um
Insensitive to wavelenght and polarization
With power consumption of 45mw
crosstalk is less than -25db
Switching time is less than 1ms

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A NOVEL TYPE OF 2x2 DIGITAL OPTICAL SWITCH
REALIZED BY POLYMER WAVEGUIDE TECHNOLOGY
Norbert Keil, Huihai Yao, Crispin Zawadzki
22nd European Conference on Optical Communication - ECOC’96, Oslo

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A NOVEL TYPE OF 2x2 DIGITAL OPTICAL SWITCH
REALIZED BY POLYMER WAVEGUIDE TECHNOLOGY
Norbert Keil, Huihai Yao, Crispin Zawadzki
22nd European Conference on Optical Communication - ECOC’96, Oslo
Pel-E2 = 65 mw
Pel-E2’ >45 mw
crosstalk < -25 dB
Pel-EI = 45 mw
Pel-E2’ >45 mw
crosstalk < -25 dB
Switching time is less than 1ms

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Asymmetric X-Junction Thermooptic Switches
Based on Fluorinated Polymer Waveguides
Min-Cheol Oh,Hyung-Jong Lee, Myung-Hyun Lee,Joo-Heon Ahn
IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 10, NO. 6, JUNE 1998
FPAE (fluorinated poly arylene ethers) as core
PFCB (Perfluorocyclobutane) as cladd
Crosstalk less than -20db
Switching power is 10mw
Insertion loss 4.5db
Risetime is 2ms

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A DIGITAL OPTICAL SWITCH (DOS) IN POLYMER USING
TRUNCATED-STRUCTURAL X-BRANCHES (TSXB)
M.K.Pandit,H.P.Chan,K.S.Chiang,S. Ghosh and A.K.Das
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 27, No. 4, November 20 2000
PMMA (poly methyl methacrylate)
Refractive index is 1.5465
Advantages of TSXB:
Decrease sensivity to Fabrication process
Usefull for Wide-angle applications
For Bandwidth : 145nm (1470-1615 nm)
include C & L bands:
Crosstalk < -18db
This structure with BCB(benzocyclobutene)
and A=0.7 degree
bandwidth is 230nm (1390-1620)
crosstalk less than -20 db
NXB
TSXB

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A DIGITAL OPTICAL SWITCH (DOS) IN POLYMER USING
TRUNCATED-STRUCTURAL X-BRANCHES (TSXB)
M.K.Pandit,H.P.Chan,K.S.Chiang,S. Ghosh and A.K.Das
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 27, No. 4, November 20 2000
Normal State Switched State

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A DIGITAL OPTICAL SWITCH (DOS) IN POLYMER USING
TRUNCATED-STRUCTURAL X-BRANCHES (TSXB)
M.K.Pandit,H.P.Chan,K.S.Chiang,S. Ghosh and A.K.Das
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 27, No. 4, November 20 2000
Normal State Switched State

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A DIGITAL OPTICAL SWITCH (DOS) IN POLYMER USING
TRUNCATED-STRUCTURAL X-BRANCHES (TSXB)
M.K.Pandit,H.P.Chan,K.S.Chiang,S. Ghosh and A.K.Das
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 27, No. 4, November 20 2000
λ=1.45um & crosstalk= -22db λ=1.55um & crosstalk=-18db
With D1=2.2um D2=3.15um minimum crosstalk shifts to λ=1550nm
Other work with BCB at 2002 yield:
crosstalk: -20db
bandwidth: 230nm (1390-1620nm)

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Polyimide-waveguide-based thermal optical switch using
total-internal-reflection effect
Jianyi Yang, Qingjun Zhou, and Ray T. Chen
Appl. Phys. Lett., Vol. 81, No. 16, 14 October 2002
Ultradel 9120 with n=1.535 as core
Ultradel 9020 with n=1.527 as cladd
At λ=1.55um crosstalk less than -28db
Independent of polarization
Switching time is 2ms

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Polyimide-waveguide-based thermal optical switch using
total-internal-reflection effect
Jianyi Yang, Qingjun Zhou, and Ray T. Chen
Appl. Phys. Lett., Vol. 81, No. 16, 14 October 2002
V=0 , cross state V>0 , bar state

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A Wide-Angle X-Junction Polymeric Thermooptic
Digital Switch With Low Crosstalk
Hau Ping Chan, Chi Kin Chow, and Alok K. Das
IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 15, NO. 9, SEPTEMBER 2003
BCB(benzocyclobutene) with n=1.54 as
core
At λ=1.55um crosstalk less than -24db
rise time is 140us & fall time is 210us

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A Wide-Angle X-Junction Polymeric Thermooptic
Digital Switch With Low Crosstalk
Hau Ping Chan, Chi Kin Chow, and Alok K. Das
IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 15, NO. 9, SEPTEMBER 2003

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Polarization-Independent All-Wave
Polymer-Based TIR Thermo-Optic Switch
Xiaolong Wang, Brie Howley, Maggie Y. Chen, and Ray T. Chen
JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 24, NO. 3, MARCH 2006
ZPU12-460 with n=1.46 as core
ZPU12-450 with n=1.45 as cladd
Dimension is reduced so power is
reduced to 25-26mw
risetime=1.5ms & falltime=2ms
Bandwidth=4200nm (.6-4.8um)

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Polarization-Independent All-Wave
Polymer-Based TIR Thermo-Optic Switch
Xiaolong Wang, Brie Howley, Maggie Y. Chen, and Ray T. Chen
JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 24, NO. 3, MARCH 2006
D & L & θ are three important parameters
1) D=50um & θ=4 degree
2) L=1400um & θ=4 degree
3) D=50um & L=1400um

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Polarization-Independent All-Wave
Polymer-Based TIR Thermo-Optic Switch
Xiaolong Wang, Brie Howley, Maggie Y. Chen, and Ray T. Chen
JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 24, NO. 3, MARCH 2006
risetime=1.5ms & falltime=2ms
Bandwidth=4200nm (.6-4.8um)

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Thanks for your attention !