Power and photon energy dependence on near-field etching properties

Our paper was accepted in Appl. Phys. A

T. Yatsui, H. Saito, K. Nishioka, B. Leuschel, O. Soppera, and K. Nobusada, “Effects of a power and photon energy of incident light on near-field etching properties,” Appl. Phys. A,  Volume 123, Issue 12, December 2017, 751

[Significance of this article]

This study investigates the effects of power and photon energy of incident light on the properties of near-field etching. Using time-dependent density functional theory, we first established that an optical near-field with photon energy lower than the absorption edge of the molecules can induce molecular vibrations. The study of power dependence of the near-field etching properties using nanodiamonds showed that the etching volume varies linearly with the incident power. Furthermore, the study of photon energy dependence using TiO₂ nanostriped structures indicated that the etching rate decreases with decrease in the photon energy. We believe that our study makes a significant contribution to the literature because optical near-fields exhibit unique properties, and research in the field of near-field optics is required for applications in future nanoscale devices.