8results about "Light beam reproducing" patented technology

A magnetic medium is described which includes a thin film magnet structure formed of a ferromagnetic alloy or compound. The thin film magnet structure includes one or more ferromagnetic domains and is coupled to one or more optical structures. Each of the one or more ferromagnetic domains have a magnetization that is switchable between two or more states. Each of the one or more optical structures is configured to increase absorbance of light at a target wavelength in the thin film magnet structure, such that in response to illumination of a ferromagnetic domain with continuous-wave light including the target wavelength, that ferromagnetic domain undergoes all-optical magnetic switching.

Described are optical magnetic recording systems, writers, media, and methods that utilize pulses of electromagnetic radiation to deterministically record information on magnetic storage media unaided by any additionally applied magnetic field such as from a write pole. The recording pulses may be linearly (or longitudinally) polarized pulses or circularly polarized pulses. The pulses may be modulated in accordance with data bits to be written on the media. Modulation may include modulating the polarization state(s) of the pulses and / or modulating the amplitude(s) the pulses, depending on the particular construction or configuration of the magnetic storage media to be used. Described are recording systems and methods that include laser light pulse generation, light pulse modulation, light pulse delivery, and magnetic media constructions.

Methods for recording and reproducing holograms include recording a hologram in a thresholded opto-magnetic medium by producing a collimated recording beam with a pulsed laser. The intensity of the recording beam is selectively modulated by passage through a modulator and spatially shaped by passage through a shaping element. The recording beam is made convergent by passage through an aspheric lens and is deflected bidirectionally with a MEMS mirror that is in operative connection with the modulator. Multiple disposed locations on a surface of the medium are exposed to a constriction of the convergent shaped beam causing a change in the medium. The hologram is reconstructed by illuminating the medium with a collimated laser beam and focusing light with a lens onto a detection matrix.

The classification device (1) comprises a pre-processing unit (10), an identification unit (30), and a material system (20) positioned between the pre-processing unit and the identification unit. The material system (20) comprises a heterogeneous magnetic medium (50) subdivided into a plurality of regions (51), each region being magnetically connected to at least one adjacent region via a coupling link (53). According to the present invention, the material system (20) further comprises control means (71, 73) for setting the coupling value of each coupling link.

The present invention belongs to the technical field of magnetization field customization, and in particular provides a method for inducing a super-diffraction-limited magnetization field in any orientation. The present invention only utilizes the radiation field of a single magnetic dipole antenna and superimposes a first-order corresponding spatial spiral phase thereon, and then the analytical expression of the vector optical field at the pupil plane of an optical tight focusing system can be obtained reversely; the Deby vector diffraction integral theory is used to quantitatively evaluate the tight focusing field of the vector optical field, and based on the inverse Faraday effect, the characteristics of the target magnetization field induced by this tight focusing field in a magnetic material are evaluated; the method of the present invention does not require a complex optimization process, and constructs a purely transverse circularly polarized near-diffraction-limited optical focal spot and induces a super-diffraction-limited magnetization field with a specified spatial orientation. The optical focal field customized by this method and the induced magnetization field have broad application prospects in the fields of optical tweezers, optical processing, all-optical magnetic storage, etc.

Provided is a magnetic disk device capable of improving performance and data reliability. A magnetic disk device according to an embodiment includes: a disk having a first track; a head which has a heater and which writes data to and reads data from the disk; and a controller that divides the first track into a plurality of divided regions, and sets a plurality of refresh thresholds for executing rewrite processing for each of the plurality of divided regions in the first track. When it is determined that a first number of writes for data to an adjacent division region adjacent to a first division region in the radial direction of the disk among the plurality of division regions is greater than a first refresh threshold among the plurality of refresh thresholds corresponding to the first division region, processing for rewriting data is performed in the first track.

The invention relates in a first aspect to a master plate for industrial hologram replication, comprising a flat and planar composite pane having a thick glass pane as a carrier for minimizing the deflection of the master plate and a thin glass pane for protecting a master hologram layer from mechanical influences, and at least one master hologram layer extending between the glass panes which has the optical function of a hologram, wherein the thick glass pane has a thickness perpendicular to the planar extent of greater than 2 millimeters, wherein the thin glass pane has a thickness perpendicular to the planar extent of between 2 millimeters and 0.1 millimeters, and wherein an unevenness of the composite pane is preferably less than 0.03% of a length of a direction of extent of the surface of the planar composite pane. In a second aspect, the invention relates to a method for producing a master plate.