Enhanced Readout Signal of Elliptic-Bubble Super Resolution Near Field Structure by Temperature-Dependent Complex Refractive Index of Phase-Change Medium

Abstract

We propose a model elucidating the readout mechanism of the super resolution near-field structure (super-RENS) with an elliptic-bubble structure. The temperature dependence of the complex refractive index of Ge 2 Sb 2 Te 5 is determined by in situ ellipsometry. The complex refractive index of Ge 2 Sb 2 Te 5 shows quite an abrupt change at approximately 608 C. The temperature profile is calculated using a proposed first-order differential equation. Above the threshold readout power, Ge 2 Sb 2 Te 5 is locally heated over the critical temperature when thickest region of Ge 2 Sb 2 Te 5 is in commensurate with the center position of the Gaussian laser power distribution, which results in the abrupt amplification of signal-to-noise ratio (SNR) of the calculated reflectance. Thus, a model revealing the essential aspect of the elliptic-bubble super-RENS is proposed to elucidate its readout mechanism.

Fast modulation of surface plasmons based on the photothermal effect of nonvolatile solid thin films

“…Since the RI of GST changes from 4.0 to 3.5 when it is amorphized (ESI Fig. S1b†), 31 the plasmon peak blue-shifts from ∼800 to ∼760 nm, as confirmed with simulations (Fig. 1e).…”

“…Germanium antimony telluride (GST) is a well-known phase change material, 30,31 which has been vigorously applied for metasurface modulation, 32–34 all-photonic non-volatile multi-level memory, 35 circuits 36,37 and optoelectronic switches. 38 However, their modulation frequencies are mostly in the infrared region, 39–42 which fails to address much wider applications in the visible region.…”

Three-dimensional analysis of silver nano-particles doping effects on super resolution near-field structure

“…Currently, there is great interest in techniques that may overcome this limit. One of the promising techniques is using a storage medium which employs a super-resolution near-field structure (Super-RENS [1][2][3][4][5][6][7]). A Super-RENS structure is composed of an active layer that is sandwiched between two dielectric films, and this three layer stack is deposited directly on the phase change data layer of the disk.…”

Spectroscopic Ellipsometry Measurements for Liquid and Solid InSb around Its Melting Point

“…To show reversibility is very important for the proof of the reliable sample preparation because some previous papers did not show such reversibility in optical measurement. 5,6,16) I think those results reflected the process of evaporation or oxidization of chalcogenide materials. The increase of É in the liquid indicates that it is the liquid InSb that becomes opaque rather than the solid, which is in contrast to the experimental result for Sb 2 Te 3 .…”