On a thermally induced readout mechanism in super-resolution optical disks

Abstract

Effect of constituent phases of reactively sputtered Ag O x film on recording and readout mechanisms of superresolution near-field structure diskRecording and readout mechanisms of super-resolution near-field structure disk with a silver oxide mask layerWe have simultaneously measured the carrier-to-noise ratio ͑CNR͒ as well as the transmitted and reflected light intensities from platinum oxide based super-resolution near-field structure ͑PtO x super-RENS͒ disks. The the reflected and transmitted light intensities were found to decrease and increase, respectively, as the CNR value increased. The phase-change material AgInSbTe ͑AIST͒ used in PtO x super-RENS disks was found to exhibit a strong optical nonlinearity with respect to readout laser power. AIST becomes transparent at higher laser powers. To ascertain whether the presence of Pt nanoparticles is important to the readout mechanism, a super-RENS disk was fabricated in which the PtO x layer was replaced with a metal-free phthalocyanine ͑H 2 Pc͒ layer and the CNR of the H 2 Pc disk was measured. From the observation that the CNR value was equivalent to that of a disk made using PtO x , we conclude that the presence of nanoparticles does not play an important role in the super-RENS readout mechanism. Finally, we also investigated the use of Si and the alloy Ge 2 Sb 2 Te 5 in lieu of AIST in a super-RENS disk and simple three layer structure disks. The super-resolution effect was observed for all disk types. Based upon these observations, we discuss the possibility of a thermal origin for the super-resolution effect in all super-resolution disks.

Phase-Change Materials for Data Storage Applications

“…The effect of super-resolution may be achieved by various types of interaction between matter and light. No consensus on the exact origin of the Super-RENS-effect using the aforementioned materials has been reached yet [102][103][104][105][106][107][108].…”

Research progress of super-resolution near-field structure (super-RENS) for optical storage

“…The phase-change material AgInSbTe (AIST) used in PtO x super-RENS discs was found by Kuwahara, et al [17] to exhibit LJ a strong optical nonlinearity with respect to readout laser power. Our group [18] practically obtained super-resolution recording marks by using an organic photochromic diarylethene mask layer in the super-RENS under a low recording laser power.…”

In-situ Raman scattering spectroscopy for super resolution optical disk

“…Concerning the origin of the SRR phenomenon, it became clear that heat generated by a readout laser light plays an important role [1][2][3][4][5] and the heat changes optical properties of a functional layer in the SRR disk. Basic studies to understand the SRR phenomenon are often carried out using a conventional disk drive tester.…”