A Review of Optical Disk Systems with Blue-Violet Laser Pickups

Abstract

We have applied the blue-violet laser in developing several technologies for the next-generation digital versatile disk (DVD). We are convinced that four items, i.e., large capacity, high data-transfer-rate, cyclability, and portability, are equally important. We have set targets for capacity and data-transfer-rate. Separate development processes have been carried out in the fields of optical heads, systems (servo-mechanisms, read/write channel and signal processing) and basic subjects and combined the results to achieve our targets. Basic subjects that cross these technical fields and have previously been neglected were studied to find solutions to new problems that arise with next-generation requirements.

Precipitation of Ag2Te in the thermoelectric material AgSbTe2

“…The compound also has applications as an optical phase-change material [9][10][11]. Both the TAGS and LAST materials have complex microstructures that are thought to enhance the thermoelectric performance by affecting the electron (increasing the Seebeck coefficient) and phonon (lowering the thermal conductivity) scattering at embedded interfaces [4,5,[12][13][14].…”

Crystallization and C-RAM application of Ag-doped Sb2Te3 material

“…Amorphous chalcogenide semiconductor films have been commercially used for optical disk due to the change in optical property as phase change occurs [2,3]. A much larger change of electrical conductivity is also observed during the process.…”

Synthesis and characterization of phase change memory cells

“…PCM is expected to become the main stream technology to replace the flash memory [3][4][5][6] . PCM offers high scalability, good stability, low process complexity, low cost, relatively high operation speed, and good compatibility with complementary metal--oxide-semiconductor (CMOS) process [7][8][9][10] . It makes use of the phasechange material which can be rapidly heated and quenched to either amorphous or crystalline phases that strongly differ in resistance.…”