Measurements of Temperature Dependence of Optical and Thermal Properties of Optical Disk Materials

Abstract

We have experimentally determined the temperature dependences of the refractive index and thermal conductivity for several optical disk materials from room temperature to 200–300°C. A novel system for obtaining thermal conductivity in the films is also introduced. As a demonstration, temperature simulation inside a simple-structured disk with and without considerating the temperature dependence of the refractive index at a 405 nm wavelength was carried out, and the difference was approximately 15°C at maximum temperature.

Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge2Sb2Te5

“…As suggested from the electronic band structure19 and in contrast to the above observation, visible to near-UV photoexcitation brings the system to a different excited state that can also induce amorphization along the edge of the potential energy surface. Besides, the absorption spectrum reaches a maximum in visible range (around 2.6 eV)20. Here, the amorphization dynamics in GST induced by visible to near-ultraviolet (UV) photoexcitation should fully exploit the nonthermal phenomena in optical media materials.…”

Thermal Conductivity Measurements of Sb–Te Alloy Thin Films Using a Nanosecond Thermoreflectance Measurement System

“…We have reported previously on the temperature dependences of the thermal and optical properties of optical disk materials, namely, chalcogen and dielectric materials. [9][10][11][12] In this paper, we report on the thermal conductivities of three different Sb-Te alloy thin films (in the low-temperature crystalline state) as well as those of Sb and Te at room temperature. Sb-Te alloys are widely used as recording media for optical disks, as the functional layer of superresolution disks, 13,14) and as resistive-element materials in phase-change memory.…”

“…Detailed descriptions of the principles of the Nano-TheMS, [15][16][17][18][19] experimental setup, and related conditions regarding this measurement technique have been previously published. [9][10][11] All experiments were carried out at room temperature and in Ar gas ambient to avoid oxidization. For analysis of the thermal conductivity, the specific heat capacity and the density of all materials should also be required.…”

Material selection and disc structure optimization studies for super-resolution readout with PtOx recording layer

“…Degree of accuracy on temperature should be improved when taking the temperature dependence of the values into account. 14 …”