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A blue magnetic optical disk

An optical disc and Blu-ray technology, applied in magnetic recording, magnetic recording, beam reproduction, etc., can solve the problem of Kerr effect reduction and achieve the effects of improving structure, increasing signal-to-noise ratio, and saving costs

Inactive Publication Date: 2007-05-16
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the increase of the readout laser power will cause the temperature in the focused spot to be too high, which will further reduce the Kerr effect. How to keep the temperature of the recording layer from rising too high under the action of high-power focused blue light is the optimal design of TbFeCo Blu-ray magneto-optical discs key

Method used

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Embodiment 1

[0019] Regarding the Blu-ray magneto-optical disc structure of the present invention shown in FIG. 1b, the thickness of each film layer must be determined first. According to the optimal design of the film system based on the optical feature matrix, a group of film thicknesses are obtained as follows: the first dielectric layer is 30nm, the recording layer is 25nm, the thermal control layer is 10nm, the second dielectric layer is 50nm, and the reflective layer is 100nm. At this time, the Kerr angle of the film system is 0.7255 degrees, and the reflectivity is 20.29%. When optimizing the design, the laser wavelength is 410nm, which is the wavelength of blue light. Except for the thermal control layer, the conventional magneto-optical disk shown in Fig. 1a and the blue-ray magneto-optical disk of the present invention have the same film thickness parameters, and the thermal properties of the two magneto-optical disk structures are compared at this time. Figure 2 shows the maxim...

Embodiment 2

[0021] Four-layer and five-layer film samples were prepared by SPF-430H magnetron sputtering system. The film thickness of each film layer is the same as embodiment 1. The ultimate vacuum of the sputtering system can reach 7×10 -5 Pa, using Ar gas as sputtering gas, N 2 As the SiN reactive sputtering gas, the sputtering power is 400kV, and the sputtering pressure is 2Pa. Glass is used as the substrate material, and its size is Φ2cm. For the film samples with four-layer and five-layer structures prepared by sputtering, the focused spot Kerr effect test device is used, as shown in Figure 5. The temperature effect is investigated. When measuring, the laser beam from the substrate layer incident. due to Tb 22 (Fe 85 co 15 ) 78 The compensation temperature of the film is less than room temperature, so when the laser is irradiated, the temperature of the film increases and its coercive force decreases. When close to the Curie temperature, the coercive force is close to 0. F...

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Abstract

This invention discloses one blue light magnetic disc, which comprises underlay, first SiN media layer, TbFeCo record layer, second SiN media layer and A1 reflection layer. The invention is characterized by the following: the said record layer and second SiN media layer set with one layer of thermal control film. This invention coats one layer of metal film tightly to record layer as heat transmission layer to control over high temperature of record layer to improve the read valve efficiency and to improve signal to noise proportion.

Description

technical field [0001] The present invention relates to an optical disc for information storage, more specifically to a Blu-ray magneto-optical disc which improves the reading threshold power of the magneto-optical disc under blue light and improves the signal-to-noise ratio. Background technique [0002] With the continuous increase of magneto-optical storage capacity, using short-wavelength laser (blue light) as the recording and reading light source has become an inevitable trend in the development of the next generation of magneto-optical disks. Therefore, the storage medium is required to have a larger Kerr effect at the blue light. Materials such as MnBi, Pt-Co, and garnet oxide have large Kerr angles at short wavelengths, and are candidates for a new generation of magneto-optical storage media. However, there are still many problems to be solved in the practical application of these media. Rare-earth transition metal (TbFeCo) thin films are currently practical magneto...

Claims

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Application Information

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IPC IPC(8): G11B11/105G11B7/24G11B5/66G11B7/2433
Inventor 王现英
Owner SHANGHAI INST OF TECH
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