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HYBRID SILICON-VANADIUM DIOXIDE MODULATORS AND

TRANSFORMATION OPTICS COUPLERS FOR OPTICAL INTERCONNECTS

By

Petr Markov

Dissertation

Submitted to the Faculty of the

Graduate School of Vanderbilt University

in partial ful�llment of the requirements

for the degree of

DOCTOR OF PHILOSOPHY

in

Electrical Engineering

May, 2015

Nashville, TN

Approved:

Professor Sharon M. Weiss

Professor Richard F. Haglund, Jr.

Professor Jason Valentine

Professor Kirill Bolotin

Professor Yaqiong Xu

Page 2

Copyright' 2015 by Petr Markov
All Rights Reserved

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wavelength, as illustrated in Fig. 3.2(d). This configuration allows for the insertion loss to

be decreased dramatically and the modulation depth increased to 7 dB. In this work, the

modulator switching time was commensurate with the full-width-at-half-maximum of the

exciting laser pulse (∼25 ns).

The two aforementioned experiments laid the ground work for future investigation of

Si-VO2 hybrid electro-optic modulators, but the devices in these experiments were not

electro-optic modulators. In both experiments, it was not an electrical signal triggering an

optical change, but rather a change in temperature either by thermal or optical heating. The

next step in VO2 modulator research was to integrate an electrical signal for triggering the

phase transition in VO2. In order to activate the phase transition based on an applied bias,

Joushaghani et. al. used an integrated heater made of silver that also served as a plasmonic

waveguide [15]. The device achieved high modulation depth (7 dB), but relatively slow

modulation speed: 40 kHz. Since the voltage and resulting current are completely localized

within the silver layer, electrical switching of VO2, as considered by the VO2 community,

was not accomplished. Electrical switching of VO2 is described in detail in the next section.

3.1.2 VO2 Electrical Switching

Experiments investigating the underlying mechanism of the electrically induced semiconductor-

metal transition (SMT) in VO2 date back to 2000 when Stefanovich et. al. [57] reported

that electric field or electron injection could induce the SMT in VO2. They argued that

their modeling showed that the leakage current was insufficient to raise the temperature of

the device above the critical temperature Tc [90]. In the ensuing years, several groups have

studied the electrically induced SMT in VO2 and argued that the primary switching mech-

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Figure 3.2: The SEM images of (a) a lithographically defined 2 µm-wide polycrystalline
VO2 tab across a Si waveguide from ref. [14], (b) a Si ring resonator modulator with VO2
patch in false color (red) from ref. [9], and (c) a hybrid SPP-VO2 switch with an integrated
heater from ref. [15]. (d) Optical resonance spectrum for on and off states for hybrid
Si-VO2 ring resonator from ref. [9].

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[101] J. Sakai, M. Zaghrioui, M. Matsushima, H. Funakubo, and K. Okimura. Impact of thermal
expansion of substrates on phase transition temperature of VO2 films. Journal of Applied
Physics, 116(12):–, 2014.

[102] S. Zhang, M. A. Kats, Y. Cui, Y. Zhou, Y. Yao, S. Ramanathan, and F. Capasso. Current-
modulated optical properties of vanadium dioxide thin films in the phase transition region.
Appl. Phys. Lett., 105(21):–, 2014.

[103] J. Rozen, R. Lopez, R. F. Haglund, and L. C. Feldman. Two-dimensional current percolation
in nanocrystalline vanadium dioxide films. Appl. Phys. Lett., 88(8):–, 2006.

[104] A. Zimmers, L. Aigouy, M. Mortier, A. Sharoni, Siming Wang, K. West, J. Ramirez, and
Ivan Schuller. Role of thermal heating on the voltage induced insulator-metal transition in
VO2. Phys. Rev. Lett., 110(5):056601, 2013. PRL.

[105] C. Zener. A theory of the electrical breakdown of solid dielectrics. Proceedings of the Royal
Society of London A: Mathematical, Physical and Engineering Sciences, 145(855):523–529,
1934. ISSN 0950-1207. doi: 10.1098/rspa.1934.0116.

[106] S. D. Ganichev, E. Ziemann, W. Prettl, I. N. Yassievich, A. A. Istratov, and E. R. Weber. Dis-
tinction between the Poole-Frenkel and tunneling models of electric-field-stimulated carrier
emission from deep levels in semiconductors. Phys. Rev. B, 61:10361–10365, Apr 2000.

[107] J. S. Brockman, L. Gao, B. Hughes, C. T. Rettner, M. G. Samant, K. P. Roche, and S. P.
Parkin-Stuart. Subnanosecond incubation times for electric-field-induced metallization of a
correlated electron oxide. Nat. Nano., 9(6):453–458, 2014.

[108] A. A. Stabile, S. K. Singh, T.-L. Wu, L. Whittaker, S. Banderjee, and G. Sambandamurthy.
Separating electric field and thermal effects across the metal-insulator transition in vanadium
oxide nanobeams, 2014.

[109] Z. Tao, T.-R. T. Han, S. D. Mahanti, P. M. Duxbury, F. Yuan, C.-Y. Ruan, K. Wang, and
J. Wu. Decoupling of structural and electronic phase transitions in VO2. Phys. Rev. Lett., 109
(16):166406, 2012. PRL.

[110] M. Rini, Z. Hao, R. W. Schoenlein, C. Giannetti, F. Parmigiani, S. Fourmaux, J. C. Kieffer,
A. Fujimori, M. Onoda, S. Wall, and A. Cavalleri. Optical switching in VO2 films by below-
gap excitation. Appl. Phys. Lett., 92(18):–, 2008.

[111] T.-L. Liu, K. J. Russell, S. Cui, and E. L. Hu. Two-dimensional hybrid photonic/plasmonic
crystal cavities. Opt. Express, 22(7):8219–8225, 2014.

[112] X. Yang, A.i Ishikawa, X. Yin, and X. Zhang. Hybrid photonic-plasmonic crystal nanocavi-
ties. ACS Nano, 5(4):2831–2838, 2011.

[113] R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang. A hybrid plasmonic
waveguide for subwavelength confinement and long-range propagation. Nat. Photon., 2(8):
496–500, 2008. 10.1038/nphoton.2008.131.

[114] P. Markov, K. Appavoo, R. F. Haglund, and S. M. Weiss. Hybrid Si-VO2-Au optical modu-
lator based on near-field plasmonic coupling. Opt. Express, 23(5):6878–6887, Mar 2015.

113

Page 129

[115] M. Nakano, K. Shibuya, D. Okuyama, T. Hatano, S. Ono, M. Kawasaki, Y. Iwasa, and
Y. Tokura. Collective bulk carrier delocalization driven by electrostatic surface charge ac-
cumulation. Nature, 487(7408):459–462, 2012. 10.1038/nature11296.

[116] K. Appavoo and R. F. Haglund. Detecting nanoscale size dependence in VO2 phase transition
using a split-ring resonator metamaterial. Nano Letters, 11(3):1025–1031, 2011.

[117] K. Appavoo and R. F. Haglund Jr. Polarization selective phase-change nanomodulator. Sci.
Rep., 4, 2014.

[118] F. Yaghmaie, J. Fleck, A. Gusman, and R. Prohaska. Improvement of PMMA electron-beam
lithography performance in metal liftoff through a poly-imide bi-layer system. Microelec-
tronic Engineering, 87(12):2629–2632, 2010.

[119] P. Markov, J. D. Ryckman, R. E. Marvel, K. A. Hallman, R. F. Haglund, and S. M. Weiss.
Silicon-VO2 hybrid electro-optic modulator. In CLEO: 2013, OSA Technical Digest (online),
page CTu2F.7. Optical Society of America, 2013.

[120] A. Crunteanu, J. Givernaud, J. Leroy, D. Mardivirin, C. Champeaux, J.-C. Orlianges,
A. Catherinot, and P. Blondy. Voltage- and current-activated metalcinsulator transition in
VO2-based electrical switches: a lifetime operation analysis. Science and Technology of
Advanced Materials, 2010.

[121] J. Nag, R. F. Haglund, A. E. Payzant, and K. L. More. Non-congruence of thermally driven
structural and electronic transitions in VO2. J. of Appl. Phys., 112(10):103532, 2012.

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