TY - JOUR
T1 - Modeling and design of high-speed ultralow voltage GaAs electro-optic modulators enabled by transparent conducting materials
AU - Yi, Fei
AU - Ou, Fang
AU - Liu, Boyang
AU - Huang, Yingyan
AU - Marks, Tobin J.
AU - Ho, Seng Tiong
PY - 2012
Y1 - 2012
N2 - We present a comprehensive modeling study of a high-speed gallium arsenide electro-optic modulator with ultralow switching voltages and large modulation bandwidths enabled by transparent conducting (TC) electrodes. The driving voltage, optical insertion loss, and modulation bandwidth of the TC-enabled modulator are systematically analyzed. Optimized designs for both a top-down and a side conduction geometry using Ta2O5 as both buffer and side cladding layers are presented. The results predict half-wave voltages from 0.5 down to 0.2 V, optical insertion losses of 6-10 dB, and optical 3 dB modulation bandwidths from 25-50 GHz for a top-down conduction geometry and 15-30 GHz for a side conduction geometry, assuming that proper impedance transforming parts and terminations are used. The use of benzocyclobutane as side cladding layers in the top-down conduction geometry to realize direct impedance matching was also explored. The corresponding modulation bandwidths are 13 GHz for 0.5 V case and 6 GHz for 0.2 V case, mainly limited by RF-optical wave velocity mismatch.
AB - We present a comprehensive modeling study of a high-speed gallium arsenide electro-optic modulator with ultralow switching voltages and large modulation bandwidths enabled by transparent conducting (TC) electrodes. The driving voltage, optical insertion loss, and modulation bandwidth of the TC-enabled modulator are systematically analyzed. Optimized designs for both a top-down and a side conduction geometry using Ta2O5 as both buffer and side cladding layers are presented. The results predict half-wave voltages from 0.5 down to 0.2 V, optical insertion losses of 6-10 dB, and optical 3 dB modulation bandwidths from 25-50 GHz for a top-down conduction geometry and 15-30 GHz for a side conduction geometry, assuming that proper impedance transforming parts and terminations are used. The use of benzocyclobutane as side cladding layers in the top-down conduction geometry to realize direct impedance matching was also explored. The corresponding modulation bandwidths are 13 GHz for 0.5 V case and 6 GHz for 0.2 V case, mainly limited by RF-optical wave velocity mismatch.
KW - Electro-optic (EO) modulation
KW - gallium arsenide (GaAs)
KW - transparent conducting oxide (TCO)
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U2 - 10.1109/JLT.2012.2186556
DO - 10.1109/JLT.2012.2186556
M3 - Article
AN - SCOPUS:84860287703
VL - 30
SP - 1985
EP - 1993
JO - Journal of Lightwave Technology
JF - Journal of Lightwave Technology
SN - 0733-8724
IS - 12
M1 - 6144684
ER -