Open AccessSilicon waveguide optical modulator driven by metal–insulator transition of vanadium dioxide cladding layer
Author(s) -
Keisuke Shibuya,
Yuki Akizuki,
Tomoya Yoshida,
Youichi Sakakibara,
Masahiko Mori,
Akihito Sawa
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.004147
Subject(s) - cladding (metalworking) , materials science , extinction ratio , transmittance , optics , optoelectronics , waveguide , metal , composite material , wavelength , physics , metallurgy
We have fabricated compact optical modulators consisting of a Si waveguide with a VO 2 cladding layer. These devices showed a sharp decrease in transmittance at around 60 °C, which is attributable to the metal-insulator transition of the VO 2 cladding layer. By systematically varying the length of the device, we evaluated the transmission losses per unit length of the device to be 1.27 dB/µm, when the VO 2 cladding layer was in the insulating (ON) state and 4.55 dB/µm when it was in the metallic (OFF) state. Furthermore, we found that the device showed an additional loss in the OFF state, which is attributable to a structural effect. As a result, an 8-µm-long device showed a large extinction ratio of more than 33 dB.