Optical imaging of strain in two-dimensional crystals

• DOI: 10.1038/s41467-018-02830-y
• Publication Date: 2018-01-31T13:43:44Z
• Authors: Lukas Mennel; Marco M. Furchi; Stefan Wachter; Matthias Paur; Dmitry K. Polyushkin; Thomas Mueller
• Keywords: Infinitesimal strain theory; Strain (injury); Strain engineering

Strain engineering is widely used in material science to tune the (opto-)electronic properties of materials and enhance performance devices. Two-dimensional atomic crystals are a versatile playground study influence strain, as they can sustain very large deformations without breaking. Various optical techniques have been employed probe strain two-dimensional materials, including micro-Raman photoluminescence spectroscopy. Here we demonstrate that second harmonic generation constitutes an even more powerful technique, it allows extract full tensor with spatial resolution below diffraction limit. Our method based on strain-induced modification nonlinear susceptibility due photoelastic effect. Using two-point bending determine elements molybdenum disulfide. Once identified, these parameters allow us spatially image field inhomogeneously strained sample.