Large non-thermal contribution to picosecond strain pulse generation using the photo-induced phase transition in VO2
Abstract
Picosecond strain pulses are a versatile tool for investigation of mechanical properties of meso- and nano-scale objects with high temporal and spatial resolutions. Generation of such pulses is traditionally realized via ultrafast laser excitation of a light-to-strain transducer involving thermoelastic, deformation potential, or inverse piezoelectric effects. These approaches unavoidably lead to heat dissipation and a temperature rise, which can modify delicate specimens, like biological tissues, and ultimately destroy the transducer itself limiting the amplitude of generated picosecond strain. Here we propose a non-thermal mechanism for generating picosecond strain pulses via ultrafast photo-induced first-order phase transitions (PIPTs). We perform experiments on vanadium dioxide VO2 films, which exhibit a first-order PIPT accompanied by a lattice change. We demonstrate that during femtosecond optical excitation of VO2 the PIPT alone contributes to ultrafast expansion of this material as large as 0.45%, which is not accompanied by heat dissipation, and, for excitation density of 8 mJ cm−2, exceeds the contribution from thermoelastic effect by a factor of five.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 03, 2020
- Source ID
- 10.1038/s41467-020-15372-z
Entities
People
- Alexandra M Kalashnikova
- Anatolii E. Fedianin
- Andrey Akimov
- Anthony Kent
- Armando Rúa
- Félix E Fernández
- Iaroslav A Mogunov
- Sergiy Lysenko
Organizations
- Engineering and Physical Sciences Research Council
- Royal Society
- Russian Center for Science Information
- United States Army Research Laboratory