13results about "Light beam reproducing" patented technology

The invention belongs to the technical field of magnetization field customization, and particularly provides a method for inducing a magnetization field in any direction to a super diffraction limit. According to the invention, only a radiation field of one magnetic dipole antenna is utilized, and a first-order corresponding spatial spiral phase is superposed on the radiation field, so that an analytical expression of a vector light field at an entrance pupil plane of the optical tight focusing system can be reversely obtained; quantitatively evaluating a tight focusing field of a vector light field by adopting a Debyy vector diffraction integral theory, and evaluating characteristics of a target magnetization field induced by the tight focusing field in a magnetic material based on an inverse Faraday effect; according to the method disclosed by the invention, a complicated optimization process is not needed, the pure transverse circular polarization near-diffraction limit focal spot is constructed, the super-diffraction limit magnetizing field capable of specifying the spatial orientation is induced, and the focal field customized by the method and the induced magnetizing field have wide application prospects in the fields of optical tweezers, optical processing, all-optomagnetic storage and the like.

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.

A method for increasing readout speed of information encoded on magnetic storage media uses contactless circularly polarized X-rays, allowing real-time, high-fidelity readout. Magnetic information is encoded by magnetization value and direction stored on magnetic tapes or disk drives. The method includes providing first c+ and second c− circularly polarized X-ray beams, orienting the first and second X-ray beams towards the magnetic tape, simultaneously reading out the first and second X-ray beams after passage through the same region of the magnetic tape while advancing the magnetic tape, and determining magnetic information by the difference between two readout signals from the first and second x-ray beams based on X-ray magnetic circular dichroism. Based on beam splitting, real-time readout of the magnetic signal stored on the magnetic tape is achievable by intensity signal evaluation for the first and second X-ray beams.

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.

A data storage device may include one or more disks, an actuator arm assembly comprising one or more magnetic recording heads, a laser diode positioned inside a laser diode cavity, and one or more processing devices configured to initiate a write operation, wherein initiating the write operation comprises activating a magnetic recording head corresponding to the laser diode, and applying a forward bias to the laser diode; apply a first reverse bias to the laser diode during at least one intervening event; and transition from applying the first reverse bias to the at least one laser diode to applying the forward bias to the at least one laser diode.

The present invention is entitled "Heat-Assisted Magnetic Recording (HAMR) Head with Heat Sink Material Adjacent to Waveguide". The present invention discloses a heat-assisted magnetic recording (HAMR) head having a gas bearing slider and a main magnetic pole supporting a near-field transducer (NFT). A first heat sink material is located on the cross-track side of the main pole, and a second heat sink material is located on the cross-track side of the waveguide. The second heat sink material can be in contact with the first heat sink material, and a high thermal conductivity heat shunt can interconnect the NFT with the first heat sink material and the second heat sink material. Heat from the NFT output tip flows to the second heat sink material through the NFT and the heat shunt. An optically reflective material can be located between the waveguide and the second heat sink material to improve the optical efficiency of the NFT.

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.