We report on the bistability of a self-standing thin film caused by photothermal displacement. The sample consisted of a self-standing thin film placed in front of a mirror. By irradiating the self-standing thin film with continuous wave laser light, the self-standing thin film deflected with thermoelastic bending moment. Since a standing wave of the laser light was generated by the reflection of the mirror, the bending moment generated on the film was periodic along the optical axis. The displacement of the film was found to be bistable with the laser light intensity. Simultaneously, the light intensity reflected from the sample was also bistable. These phenomena are explained by the photothermal displacement of thin film in the standing wave of laser light.
- Interference fringe
- Photothermal displacement