Mott insulator VO2exhibits an ultrafast and reversible semiconductor‐to‐metal transition (SMT) near 340 K (67 °C). In order to fulfill the multifunctional device applications, effective transition temperature (
Hybrid material systems are a promising approach for extending the capabilities of silicon photonics. Given the weak electro‐optic and thermo‐optic effects in silicon, there is intense interest in integrating an ultrafast‐switching phase‐change material with a large refractive index contrast into the waveguide, such as vanadium dioxide (VO2). It is well established that the phase transition in VO2thin films can be triggered by ultrafast, 800 nm laser pulses, and that pump‐laser fluence is a critical determinant of the recovery time of thin films irradiated by femtosecond pulses. However, thin‐film experiments are not reliable guides to a VO2:Si system for all‐optical, on‐chip switching because of the differences in VO2optical constants in the telecommunication band, and the complex sample geometry and alignment issues in a waveguide geometry. This paper reports the first demonstration that the reversible, ultrafast photoinduced phase transition in VO2can achieve sub‐picosecond response when small VO2volumes are integrated into a silicon waveguide as the active element. The result suggests that VO2can be pursued as a strong candidate for waveguide switching with sub‐picosecond on‐off times.
more » « less- NSF-PAR ID:
- 10449068
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 9
- Issue:
- 4
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Vanadium dioxide (VO2) is a well‐studied Mott‐insulator because of the very abrupt physical property switching during its semiconductor‐to‐metal transition (SMT) around 341 K (68 °C). In this work, through novel oxide‐metal nanocomposite designs (i.e., Au:VO2and Pt:VO2), a very broad range of SMT temperature tuning from
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