Abstract:
A multi-layer optical storage medium includes a transparent substrate, a partially reflective layer, a transparent spacer, and a highly reflective layer. One pattern of data pits is provided on the substrate, adjacent the partially reflective layer, and another pattern of pits is provided on the spacer layer, adjacent the highly reflective layer. The partially reflective layer may be made of amorphous selenium (a-Se) and preferably has an index of refraction having a real component, n, greater than 2.8 and an imaginary component, K, less than 0.01. The invention also includes the optical data storage systems compatible with such media.
Abstract:
The invention includes a method of generating a position error signal in a holographically imaged data recording system. This method comprises using an optical imaging system to image a plurality of holographically recorded pixels onto a plurality of camera pixels forming a data page. Each holographically recorded pixel is imaged onto an array of at least two adjacent camera pixels in any direction. The output signals from the arrays of camera pixels are used to calculate a position error signal. In a preferred embodiment, the holographically recorded pixel is imaged onto an array of four adjacent camera pixels that form a square having two pixels in each direction.
Abstract:
The disclosure is directed to optical disks with a microstructured surface formed on a surface of the optical disk. The microstructured surface may be created to promote the adhesion and prevent the migration of a print material applied to the surface of the optical disk. The microstructured surface may be in the form of a plurality of wells or a plurality of discontinuous raised features in the surface. By forming a microstructured surface on the surface of the disk, the optical disk may not need an additional coating to receive the print material while also retaining the print material at a precise location on the surface. In addition, a plurality of standoff features may be formed in an outer surface of the optical disk to help prevent damage to the surface of the optical disk.
Abstract:
The invention provides for modifications to conventional optical data storage media to reduce the amount of raw material necessary in the media construction. More particularly, a portion of a thermoplastic substrate is modified to create one or more substantial void areas compared to a conventional substrate that defines flat parallel surfaces without void areas. The configuration, number, and size of the voids may be modified in order to substantially reduce inherent raw material cost while maintaining the specified physical thickness, clamping area, and mechanical stability of the medium.
Abstract:
The invention is directed to a holographic data storage system including a spatial light modulator device (SLM) that comprises optical elements in the form of polymer dispersed liquid crystal (PDLC) elements. The PDLC elements are individually controllable, and can be made substantially transparent or substantially diffusive. The “on” or “off” state of each PDLC element is defined by whether the given PDLC element is transparent or diffusive. Additional states may also be defined for the PDLC elements, e.g., based on a level of diffusiveness of the PDLC elements. Also, a mirror layer may be added adjacent the PDLC elements to define a reflective-mode SLM. In any case, the SLM is used to encode bit maps into a holographic object beam.
Abstract:
The invention is directed to an optical element and techniques for creating the optical element. The optical element may comprise an optical delay line or a similar optical part. The optical element may have a wide variety of applications in optical data transmission, optical computing, short term transient storing, applications for optical timing, or a number of other applications. Rather than drawing a long length of optical fiber, the invention can make use of mastering and replication techniques to define a long continuous groove in a substrate. Alternatively, an etching process may be used. In either case, the groove is filled with an optical material of higher index of refraction than the substrate to define a light guide that can transmit light via total internal reflection (TIR).
Abstract:
In one embodiment, holographic data storage medium includes a first thermoplastic substrate portion having a thickness less than approximately 2 millimeters and a second thermoplastic substrate portion having a thickness less than approximately 2 millimeters. A holographic recording material may be sandwiched between the first and second thermoplastic substrate portions. By making thermoplastic substrate portions sufficiently thin, edge wedge problems can be avoided.
Abstract:
The invention is directed to self-referenced holographic recording techniques that make use of a diffusive element. Self-referenced holography refers to holographic recording techniques in which a reference beam is created from a zero frequency Fourier component of a data encoded object beam. In accordance with the invention, a diffusive element can be positioned in a holographic recording system to create the reference beam from the zero frequency Fourier component of the data encoded object beam. Using a diffusive element to create a reference beam in self-referenced holography can provide advantages to the self-referenced holographic recording system.
Abstract:
The disclosure is directed to an optical disk with a topographical surface. The topographical surface may be formed in the optical disk to create an aesthetic label for the optical disk. The topographical surface may include raised features that refract, diffuse, reflect, or diffract light that makes images of the label viewable to a user. The topographical surface may be at least partially radially coincident with a data surface of the optical disk. An optical disk that includes a topographical surface as the label may not require an additional layer or process to create the label. In some examples, the topographical surface may include raised features of high spatial frequency and configured to create a hologram label that displays images to the user.
Abstract:
Holographic data storage media having a sandwiched construction are described in which a holographic recording material is sandwiched between two substrates. The holographic media formulation is often formed of two or more components mixed to obtain a homogeneous formulation. The holographic media formulation may include two or more components which are mixed together prior to injection between the substrates. Curing of the holographic media formulation is substantially avoided during mixing, yet accelerated after the formulation is injected between the substrates. Accordingly, the system and techniques can be used to improve the large scale manufacturability of such media by allowing for fabrication of such media within reasonable cycle times, such as less than one minute, while adhering to stringent requirements for optical clarity and parallelism.