Photothermal optical modulation of ultra-compact hybrid Si-VO₂ ring resonators.
We demonstrate photothermally induced optical switching of ultra-compact hybrid Si-VO₂ ring resonators. The devices consist of a sub-micron length ~70 nm thick patch of phase-changing VO₂ integrated onto silicon ring resonators as small as 1.5 μm in radius. The semiconductor-to-metal transition (SMT) of VO₂ is triggered using a 532 nm pump laser, while optical transmission is probed using a tunable cw laser near 1550 nm. We observe optical modulation greater than 10dB from modest quality-factor (~10³) resonances, as well as a large -1.26 nm change in resonant wavelength Δλ, resulting from the large change in the dielectric function of VO₂ in the insulator-to-metal transition achieved by optical pumping.
Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, USA. j.ryckman@vanderbilt.edu
Judson D
JD
Ryckman
V
V
Diez-Blanco
Joyeeta
J
Nag
Robert E
RE
Marvel
B K
BK
Choi
Richard F
RF
Haglund
Sharon M
SM
Weiss