Stacked film reflective layers for multi-layer optical data storage

A component comprising a stacked interleaved film structure that includes a plurality of layers inert to light. Alternating layers are either doped with a reverse saturable absorber (RSA) material or the RSA material is located between the adjacent inert layers. In some embodiments, the inert alternating layers have different refractive indices. A data storage device and methods of manufacture are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related in parts both to commonly assigned, U.S. application Ser. No. 13/459,840, entitled STACKED FILM OPTICAL DATA STORAGE DEVICE AND METHOD OF MANUFACTURE, filed on Apr. 30, 2012; and, U.S. application Ser. No. 13/563,194, entitled STACKED FILM THRESHOLD COMPONENT, DEVICE, AND METHOD OF MANUFACTURE, filed on Jul. 31, 2012, the entire contents of both references which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates generally to stacked film components, devices that employ the components, methods of manufacturing the devices and/or the components, and, in particular embodiments, methods of recording and/or reading holograms on a device that incorporates aspects of the present invention.

Micro-holographic data storage enables large numbers of data layers in a single disc to achieve high data capacity. In each of the data layers, digital data “0” or “1” is represented by a presence or absence of a micro-hologram. The micro-hologram functions as a local reflector upon readout beam illumination. Presence or absence of a micro-hologram provides a “high” or “low” reflected signal that provides stored information.

Optical recording of a micro-hologram requires two counter-propagating focused coherent laser beams from both sides of the disc with overlapping focal regions. Interference of the two beams at the focal region induces local changes of the material that results in a refractive index modulation pattern, which is the micro-hologram. Good alignment of these two beams typically requires a five-axis servo system during dynamic recording. In addition, recording at all the layers through the depth of the disc requires a well aberration compensated optical system, which is very challenging at high numerical aperture. Therefore, both the optics and servo system are much more complicated and expensive than what are required in conventional optical drive systems where only a single focused beams is used for recording and/or readout.

The concept of “pre-format” was proposed to overcome this issue. (See e.g., U.S. Pat. No. 7,388,695). In this scheme, blank discs are “pre-formatted” with the micro-hologram layers before being used in an optical drive. This “pre-format” step is one of the steps in disc manufacturing. The preformatted discs are then used in an optical drive for recording and readout. The recording is done through erasure or modification of the micro-holograms using a single focused laser beam. The system for “pre-formatting” is a high quality expensive dual-side micro-hologram recording system.

Accordingly, there is an ongoing opportunity for improving upon existing optical data storage structures, methods of manufacture, methods of recording, and/or methods for reading.

BRIEF DESCRIPTION

The present invention overcomes at least some of the aforementioned drawbacks by eliminating the need to optically pre-format data storage devices. More specifically, the present invention is directed to providing a stacked film component, device, and methods of manufacture, recording, and/or reading that instead of using threshold material(s) only requires the use of commercial available polymers and Reverse Saturable Absorber (RSA) dyes.

Therefore, in accordance with one aspect of the invention, a component comprises a stacked film structure comprising a plurality of layers inert to light having a first refractive index interleaved with a plurality of layers inert to light having a second refractive index, wherein in the first refractive index is different than the second refractive index; and a plurality of layers comprising a reverse saturable absorber (RSA) material, wherein each of the plurality of layers is located between one of the plurality of layers inert to light having the first refractive index and one of the plurality of layers inert to light having the second refractive index.

In accordance with another aspect of the invention, a method of manufacture comprises method of manufacture comprises: providing a plurality of layers inert to light having a first refractive index; providing a plurality of layers inert to light having a second refractive index, wherein the first refractive index is different than the second refractive index; applying a reverse saturable absorber (RSA) material to at least one of the layer inert to light having the first refractive index and the layer inert to light having the second refractive index; and, adhering the plurality of layers inert to light having the first refractive index to the plurality of layers inert to light having the second refractive index, so that the plurality of layers inert to light having the first refractive index and the plurality of layers inert to light having the second refractive index are interleaved, thereby forming a component having the RSA material located between the layer inert to light having the first refractive index and the layer inert to light having the second refractive index.

In accordance with another aspect of the invention, a component comprises: a stacked film structure comprising a plurality of first layers inert to light interleaved with a plurality of second layers inert to light, further wherein the plurality of second layers are doped with a reverse saturable absorber (RSA) material.

In accordance with another aspect of the invention, a method of manufacture comprises: providing a plurality of layers inert to light having a first refractive index; providing a plurality of layers inert to light having a second refractive index, said plurality of layers having the second refractive index further including a reverse saturable absorber (RSA) material doped therein; and, adhering the plurality of layers inert to light having the first refractive index to the plurality of layers inert to light having the second refractive index, so that the plurality of layers inert to light having the first refractive index and the plurality of layers inert to light having the second refractive index are interleaved, thereby forming a stacked component having the doped RSA material-laden layers located between the layer inert to light having the first refractive index.

DETAILED DESCRIPTION

Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art with respect to the presently disclosed subject matter. The terms “first”, “second”, and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a”, “an”, and “the” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item, and the terms “front”, “back”, “bottom”, and/or “top”, unless otherwise noted, are used for convenience of description only, and are not limited to any one position or spatial orientation.

If ranges are disclosed, the endpoints of all ranges directed to the same component or property are inclusive and independently combinable (e.g., ranges of “up to about 25 wt. %” is inclusive of the endpoints and all intermediate values of the ranges of “about 5 wt. % to about 25 wt. %,” etc.). The modified “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity). Accordingly, the value modified by the term “about” is not necessarily limited only to the precise value specified.

As used herein, the term “non-linear sensitizer” refers to a material that has a sensitivity having dependence to the light intensity, that is, the sensitivity is high at the higher (recording) intensity and low at the lower (readout) intensity.

As used herein, the term “sensitivity” is defined as the amount of index change obtained with respect to the amount of fluence used to irradiate a spot of the film with the laser light. In general, sensitivity for linear materials and/or linear sensitizers does not change over a variety of intensities.

As used herein, the term “fluence” means the amount of optical beam energy that has traversed a unit area of the beam cross-section (measure, for example, in Joule/cm2), while the term “intensity” means optical radiative flux density, e.g., amount of energy traversing a unit area of beam cross-section in unit time (measure in, for example, Watt/cm2).

As used herein, the term “no change” in reference to change in a refractive index is meant to include a material or combination of materials that have change of less than about 0.05% change in its refractive index over a duration of time.

The term “adjoining” as used herein means either the two, or more, elements are in physical contact with each other or there may be an interstitial layer(s) therebetween the two, or more, elements. That is the two, or more, elements are joined in some fashion so as to result in a single construct.

The term “high intensity” as used herein includes light in a range from about 50 MW/cm2to about 500 MW/cm2. The term “low intensity” as used herein includes light in a range from 0.1 MW/cm2to about 30 MW/cm2.

Referring to the figures,FIG. 1depicts a sectional elevation view of a stacked film structure, or structure,10, according to an embodiment of the present invention. Aspects of the present invention provide for the use of commercially available polymers and reverse saturable absorber (RSA) material(s). That is aspects of the present invention are such that no threshold materials are required. The structure10comprises a plurality of layers inert to light having a first refractive index12. The structure10further comprises a plurality of layers inert to light having a second refractive index14. The first refractive index and the second refractive index of the layers12,14are different. As shown, the plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14are configured such that they are interleaved, or alternating, within the structure10.

As shown, between the plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14is a layer20, wherein the layer20comprises a reverse saturable absorber (RSA) material. The layer, or RSA layer,20may be placed either on the plurality of layers inert to light having a first refractive index12and/or on the plurality of layers inert to light having a second refractive index14. In any event, the ultimate structure10comprises a laminar structure wherein the RSA layer20is ultimately located between the plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14.

Various suitable RSA materials may be used for the RSA layer20. In particular embodiments, the RSA material used is sensitive to light having a wavelength in a range from about 300 nm to about 800 nm. In another particular embodiment, the RSA material used is sensitive to light having a wavelength in a range from about 380 nm to about 420 nm.

Suitable RSA dyes include, without limitation, for example a photochemically stable and thermally stable dye, such as a metal phthalocyanine dye, such as Irgaphor Ultragreen Mx (commercially available from Ciba), copper phthalocyanine, lead phthalocyanine, zinc phthalocyanine, indium phthalocyanine, indium tetra-butyl phthalocyanine, gallium phthalocyanine, cobalt phthalocyanine, platinum phthalocyanine, nickel phthalocyanine, tetra-4-sufonatophenylporphyrinato-copper(II) or tetra-4-sulfonatophenylporphyrinato-zinc(II). Suitable lasers known to excite these various “green” RSA dyes include green lasers (e.g., 532 nm). These various green RSA dyes are disclosed in U.S. patent application Ser. No. 11/376,545, now issued as U.S. Pat. No. 7,388,695, and incorporated herein by reference in its entirety for any and all purposes, so long as not directly contradictory with the teachings herein.

Other suitable RSA dyes include “blue” RSA dyes that are capable of undergoing photoexcitation upon impingement with incident actinic radiation at a wavelength of, for example, 405 nm. Several suitable RSA dyes are disclosed in U.S. Pat. No. 8,182,967 and U.S. patent application Ser. No. 12/551,455 and incorporated herein by reference in their entirety for any and all purposes, so long as not directly contradictory with the teachings herein. These blue RSA dyes generally include subphthalocyanines and platinum ethynyl based dyes. Specific examples include, but are limited to, 3,5-dibromophenoxysubphthalocyaninato]boron(III), 3-iodophenoxysubphthalocyaninato]boron(III), trans-B is (tributylphophine)bis(4-ethynylbiphenyl)platinum (PPE), trans-Bis(tributylphosphine)bis (4-ethynyl-1-(2-phenyllethynyl)benzene)platinum (PE2).

Additional suitable RSA dyes for use as the RSA layer20include the class of compounds of porphyrins, and the like.

The plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14may comprise any suitable material or combinations of materials that are inert to light or about inert to light. Examples of suitable materials for the layers12,14include, but are not limited to, poly(alkyl methacrylates), such as poly(methyl methacrylate) (PMMA), polyvinyl alcohols, poly(alkyl acrylates), polystyrenes, polycarbonates, poly(vinylidene chloride), poly(vinyl acetate), combinations thereof, and the like. Other examples of suitable materials for the layers12,14include poly(vinylidene fluoride-co-trifluoroethylene)≡PVDF, poly(vinylpyrrolidone)≡PVP, or various compositions of styrene-acrylonitrile≡SAN.

It should be noted that whileFIG. 1depicts a particular embodiment of the structure10, other configurations are available, without departing from the present invention. For example, the RSA layers20, in addition to being located at the interfaces between the layers12and14, as shown inFIG. 1, may additionally be located at the interfaces between layers14and12(not shown inFIG. 1). For illustrative purposes only, one can assign the layer having a first refractive index12an “A”; assign the layer having a second refractive index14a “B”; and, assign the RSA layer20a “C”. As such, under aspects of the present invention, various possible embodiments of the combination or order of layers12,14and RSA layer20include A-C-B-C-A-C-B-C-A; or, in another embodiment A-C-B-A-C-B-A-C-B-A; or, B-C-A-B-C-A-B-C-A-B; or, A-B-A-C-B-A-B-C-A-B-A-C, and the like.

The thickness of the plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14may be the same in certain embodiments. In other embodiments, the thickness of the plurality of layers inert to light having a first refractive index12and the plurality of layers inert to light having a second refractive index14may be different. A thickness of each of the plurality of layers inert to light12,14may be, for example, in a range from about 20 nm to about 500 nm. The layer of RSA material20is typically negligible as compared to the thicknesses of the other plurality of layers inert to light12,14. The layer of RSA material20may be, for example, less than about 5 nm in thickness.

Further, whileFIG. 1shows quantities of five and four, respectively, of the layers inert to light having a first refractive index12and the layers inert to light having a second refractive index14, other quantities are available without departing from the intent of the present invention. For example, the layers inert to light having a first refractive index12and the layers inert to light having a second refractive index14may be virtually any quantity including, for example, between two layers up to about fifty layers interleaved in the structure10.

Referring back toFIG. 1, P, is shown as a period of the structure10as is defined in Equation 1 as:
P=λ/2nEq. 1

Wherein n is neffectiveof the structure10. The layers12having a first refractive index, n1and a thickness, d1. Similarly, the layers14having a second refractive index, n2and a thickness, d2. In this manner, the components (e.g.,12,14) of structure10are configured such that Equation 2 is met:
n1d1+n2d2=λ/2  Eq. 2

In this manner, the stacked structure10is periodic in its arrangement. Depending on the particular materials employed and their respective refractive indices, different thicknesses of the materials are warranted.

Referring toFIGS. 2 and 3, sequential elevation sectional views of the embodiment fromFIG. 1undergoing a recording beam and reading beam, respectively, is shown. InFIG. 2, the component10receives a focused recording laser beam300such that the beam300impinges at305on a portion of the component10. As a result of the application of the focused recording laser beam300, portions405of the component10are thereby modified as depicted inFIG. 3. As shown schematically inFIG. 3, portions22of the RSA material20are modified as a result. Depending on what RSA material(s) are used, a suitable focused recording beam300is selected that provides the proper modification of the RSA material(s)20to the modified version22. Applications of the recording beam300on the RSA material causes the RSA material to heat and produce distortions thereby causing disruption the interface effect. As shown inFIG. 3, a focused reading laser beam400may be applied to the component10. As depicted, depending on whether the focused reading laser beam400is applied to portions405that received the focused recording beam300(FIG. 2), the reflected light from the component10will respond differently. As shown on the left portion ofFIG. 3, the reflected light410is scattered due to the application of the reading beam400on portions405that have been modified and no significant signal is returned to the detector (i.e., digital “0”). Contrastingly, the right portion ofFIG. 3, the reflected light420has little or no scatter due to the application of the reading beam400on portions of the component10that have not been modified by a recording beam300and the detector receives the reflected signal (i.e., digital “1”).

Referring toFIG. 4, a sectional elevation view of a stacked film structure, or structure,110, according to an embodiment of the present invention, is depicted. The structure110comprises a plurality of layers inert to light having a first refractive index24. The structure110further comprises a plurality of layers inert to light having a second refractive index30. The first refractive index and the second refractive index of the layers24,30are different. As shown, the plurality of layers inert to light having a first refractive index24and the plurality of layers inert to light having a second refractive index30are configured such that they are interleaved, or alternating, within the structure110.

As shown, the plurality of layers inert to light having a second refractive index30is doped with a reverse saturable absorber (RSA) material. Suitable RSA materials for use as the dopant are discussed elsewhere herein. Similarly, suitable materials for layers24,30are elsewhere discussed with regards to layers12,14.

As shown inFIG. 4, the component110receives a focused recording laser beam300such that the beam300impinges at305on a portion of the component110. As a result of the application of the focused recording laser beam300, portions405of the component110are thereby modified as depicted inFIG. 5. As shown schematically inFIG. 5, portions32of the doped second layer30are modified as a result. Depending on what RSA material(s) are doped in the layer30, a suitable focused recording beam300is selected that provides the proper modification of the material(s) second layer30to the modified version22. Applications of the recording beam300on the RSA material causes the RSA material to heat and produce distortions thereby causing disruption the interface effect. As shown inFIG. 5, a focused reading laser beam400may be applied to the component110. As depicted, depending on whether the focused reading laser beam400is applied to portions405that received the focused recording beam300(FIG. 4), the reflected light from the component10will respond differently. As shown on the left portion ofFIG. 5, the reflected light410is scattered due to the application of the reading beam400on portions405that have been modified. Contrastingly, the right portion ofFIG. 5, the reflected light420has little or no scatter due to the application of the reading beam400on portions of the component110that have not been modified by a recording beam300.

Referring collectively toFIGS. 6-9, other stacked components210,310of the present invention are depicted. As shown inFIG. 6, the component210comprise a stacked film structure that comprises a plurality of first layers inert to light124interleaved with a plurality of second layers inert to light130. The plurality of second layers inert to light130may comprise a block copolymer. The plurality of first layers inert to light124may also comprise a block copolymer, in an embodiment. The plurality of second layers inert to light130are further doped with a reverse saturable absorber (RSA) material. Suitable RSA materials are discussed elsewhere herein. Similarly, suitable materials for layers124,130are elsewhere discussed with regards to layers12,14,24,30.

In an embodiment, there may be nano-sized polyethylene oxide (PEO) crystals scattered uniformly through a polystyrene (PS) matrix that comprises the plurality of second layers inert to light130. The particles may be small enough (e.g., <25 nm) so as to prevent scattering of light. However, in the crystalline phase they increase their refractive index of the PEO/PS volume. When an RSA dye absorbs energy at the focal points, it rapidly dissipates heat and melts the crystals in that region. The then amorphous PEO in the PS causes the refractive index to decrease in that region. As a result, a characteristic fringe of varying refractive indices (i.e., hologram) is produced. In this manner, the RSA dyes used in the plurality of second layers inert to light130act as thermal heaters within the block copolymers so that the block copolymers experience a phase transition.

As shown inFIG. 6, a focused recording laser beam300is applied to portions305of the structure210. Depending on the particular embodiment used and the relative reflective indices of the layers124,130and the particular RSA materials used, the application of the beam300on the doped layer130will change the refractive index of the layer130so that the refractive indices of the layers124,130are the same, or similar, and thereby upon readout the applied light passes through the transparent regions405of the component210(seeFIG. 7) and is not returned to the detector. The portions305having had changes in the refractive index comprise hologram405.

Referring toFIG. 7, a focused reading laser beam400may be applied to the component210that has had holograms405recorded thereon. As depicted, depending on whether the focused reading laser beam400is applied to the hologram portions405that received the focused recording beam300(FIG. 6), the applied light from the component210will respond differently. As shown on the right portion ofFIG. 7, the applied light430has little, or no, scatter due to the application of the reading beam400on portions of the component210that have been modified by a recording beam300. Due to the transparency of the component210in these portions405, the light beam400passes through the component210and is not reflected.

As shown inFIG. 8, the component310comprise a stacked film structure that comprises a plurality of first layers inert to light224interleaved with a plurality of second layers inert to light230. The plurality of second layers inert to light230may comprise a block copolymer. The plurality of first layers inert to light224may also comprise a block copolymer, in an embodiment. The plurality of second layers inert to light230are further doped with a reverse saturable absorber (RSA) material. Suitable RSA materials are discussed elsewhere herein. Similarly, suitable materials for layers224,230are elsewhere discussed with regards to layers12,14,24,30,124,130.

In an embodiment, there may be nano-sized polyethylene oxide (PEO) crystals scattered uniformly through a polystyrene (PS) matrix that comprises the plurality of second layers inert to light230. The particles may be small enough (e.g., <25 nm) so as to prevent scattering of light. However, in the crystalline phase they increase their refractive index of the PEO/PS volume. When an RSA dye absorbs energy at the focal points, it rapidly dissipates heat and melts the crystals in that region. The then amorphous PEO in the PS causes the refractive index to decrease in that region. As a result, a characteristic fringe of varying refractive indices (i.e., hologram) is produced. In this manner, the RSA dyes used in the plurality of second layers inert to light230act as thermal heaters within the block copolymers so that the block copolymers experience a phase transition.

As shown inFIG. 8, a focused recording laser beam300is applied to portions305of the structure310. Depending on the particular embodiment used and the relative reflective indices of the layers224,230and the particular RSA materials used, the refractive indices of the layers224,230are the same, or similar. Upon the application of the beam300on the doped layer230will change the refractive index of the layer230so that the refractive indices of the layers224,230end up being different than each other, and thereby upon readout the applied light400reflects directly back to the detector in the regions405of the component420(seeFIG. 9). The portions305having had changes in the refractive index comprise hologram405. The heating of the portions305in the embodiment is less severe and does not deform the interfaces as discussed before. Thus, there is no, or little, scatter of light although there is a change in reflective index.

Referring toFIG. 9, a focused reading laser beam400may be applied to the component310that has had holograms405recorded thereon. As depicted, depending on whether the focused reading laser beam400is applied to the hologram portions405that received the focused recording beam300(FIG. 8), the applied light from the component310will respond differently. As shown inFIG. 9, the reflected light420has little, or no, scatter due to the application of the reading beam400on portions of the component310that have been modified by a recording beam300. Due to the transparency of other regions (i.e., not the holograms405) of the component310, the light beam400may pass through the component310and is not reflected.

Referring toFIG. 10, a sectional elevation view of a portion of a data storage device, and data storage device component, according to an embodiment of the present invention, is shown. The data storage device, depicted as100, includes a data storage device component10,110,210,310and other elements.

The data storage device100comprises a substrate layer44with the data storage device component10,110,210,310adjoined thereto. As shown adjoining a second side of the data storage device component10,110,210,310may be a second substrate layer50. The second substrate layer50may further include a servo layer46therein.

The data storage device100may further include a suitable barrier coating42on one, or both, sides of the device100. Any suitable material may be used, now known or later developed, for the barrier coating42. Further, the data storage device100may include one, or more, of an anti-scratch coating and an anti-reflection coating. Although the anti-scratch coating and/or the anti-reflection coating may be placed on both sides of the data storage device100, typically these coatings are only applied on the upper side of the data storage device100, as the upper side is the side from which read and/or writing actions are conducted on the data storage device100.

As a result, the data storage device100of the present invention may ultimately be configured so as to function as a micro-holographic data storage device. In an embodiment the micro-holographic data storage device may comprise a disc. Suitable discs may include, but are not limited to, standard disc sizes, such as a disc having a total thickness of about 1.2 mm or about 100 μm (i.e., “flexible disc”). However, the disc may be constructed to any total thickness including a range from about 100 μm to about 1.2 mm including, for example, discs having a total thickness of 100 μm, 400 μm, 600 μm, or 1200 μm, and the like.

The substrate layers44,50may comprise a moldable non-photopolymer plastic substrate. Particular examples of suitable polymers for use in the polymer matrix for the substrate layers44,50include, but are not limited to, poly(alkyl methacrylates), such as poly(methyl methacrylate) (PMMA), polyvinyl alcohols, poly(alkyl acrylates), polystyrenes, polycarbonates, poly(vinylidene chloride), poly(vinyl acetate), combinations thereof, and the like. The substrate layer50may further include a servo layer46therein that comprises grooves, or groove layer and a dichroic layer on the groove layer.

Examples of suitable substrate layers44,50, servo layer46, groove layer, dichroic layer are discussed in the following references, but are not limited to, those materials listed in commonly assigned US Patent Pub. No. 2011/0080823, Ser. No. 12/966,144, entitled “Disc Structure For Bit-Wise Holographic Storage”; and, U.S. Pat. No. 8,194,520, Ser. No. 12/346,378, entitled “Disc Structure For Bit-Wise Holographic Storage”. Both documents are hereby incorporated by reference in their entirety.

Referring now toFIGS. 11 and 12, schematic diagrams of various systems that employ methods of manufacture of a data storage device component10,110,210,310, according to embodiment of the present invention are shown. Additionally,FIGS. 13 and 14depict flowcharts depicting methods of manufacture of a component that the two systems inFIGS. 11 and 12may employ.FIGS. 11 and 12show portions of systems500,600, respectively. The systems500,600may employ a plurality of rollers552and other known elements (not shown) and an adhering device610to construct at least the layer12,14,24,30,124,130,224,230portion of a data storage device component10,110,210,310as discussed. Any suitable adhering device610may be used including a thermal press, a hot roll lamination device610(see e.g.,FIG. 12), an optical curing agent, and the like.

This method may include the use of layer multiplication coextrusion techniques that can achieve hundreds to thousands of layers. This process generally comprises the coextrusion of two separate polymers that pass through a series of dies that split the stream vertically and spread it horizontally going into the next die. Thus, the initial 2 layer multiplies into 2n+1layers to a maximum of 2048 layers with individual layers <10 nm thick [See reference: Y. Jin, H. Tai, A. Hiltner, E. Baer, James S. Shirk, Journal of Applied Polymer Science, Vol. 103, 1834-1841 (2007).] This technique has been used to make an all polymer melt-processed distributed Bragg reflector laser with layer thicknesses and spacing similar to those required in aspects of the present invention. [See reference: Kenneth D. Singer, Tomasz Kazmierczak, Joseph Lott, Hyunmin Song, Yeheng Wu, James Andrews, Eric Baer, Anne Hiltner, and Christoph Weder, OPTICS EXPRESS 2008, Vol. 16, No. 14, 10360]. Thus, the component,10,110,210,310(e.g., layers12,14) could be made in a single pass (e.g., making a plurality of layers12,14,24,30,124,130,224,230) and adhered to other layers at the end of the process to produce a data storage device100that comprises layers12,14which could be stacked separately to make the data storage device100. In other embodiments, multiplication coextrusion techniques have also included 3-layer coextrusion so the entire stack10,110,210,310could potentially be made in a single pass and used to later make the data storage device100.

A method, as shown inFIG. 13as700, may comprise providing a plurality of layers inert to light having a first refractive index at710. Similarly, a plurality of layers inert to light having a second refractive index, different than the first, is at712. At714, the RSA material is applied to at least one of the layers insert to light. Then at716, the plurality of layers of light having the first refractive index are adhered to the plurality of layers of lights having the second refractive index, at least one of which layers having the RSA material applied thereon, thereby forming an interleaved component10,110,210,310.

A flowchart depicting another method of manufacture of the component110,210,310that the system inFIG. 12may use is shown inFIG. 14as800. The system600may employ a roll-to-roll system that includes rollers552and a plurality of other elements (not shown) that are suitable so as to provide a component110,210,310.

The method800comprises at810providing a plurality of first layers inert to light. At812a plurality of second layers inert to light further doped with RSA material, are provided. At814, the plurality of first layers and the plurality of second layers (with RSA) are adhered to each other, thereby forming an interleaved structure.

In other embodiments, the component10,110,210,310and/or data storage device110thereof may also be processed through a variety and combination of film roller drum(s) and/or thermal press(es), so as to form a sheet. Additionally, in an embodiment the plurality of layers12,14and the plurality of other components are transported and aligned, via the roll-to-roll systems600shown inFIG. 12. The adhering may be provided by the adhering device530,610or similar.

Other aspects in the method may include, but are not limited to, further adhering the component10,110,210,310to one or more substrate layers, wherein the substrate layer comprises a non-photopolymer plastic substrate and a servo layer therein, thereby defining a data storage device. The device may further be cut to a predefined size and shape, so as to define a suitable data storage disc. Additional coating(s) may be applied to one or both surfaces of the disc including a barrier coating, an anti-reflection coating, and an anti-scratch coating. The barrier coating typically is applied to both sides of the disc, while the anti-reflection coating, and the anti-scratch coating are merely applied to one side (the read/write side) of the disc.

In another embodiment, these plurality of components10,110,210,310may be transported and aligned, via similar means (e.g., roll-to-roll systems) as those discussed with regards to the systems and methods depicted inFIGS. 11-14. The aligned plurality of unit hologram and spacer film structures, or components, may be adhered to each other thereby forming a component. Other film process steps in the method may include surface cleaning, treatment before coating, adding/removing protective masking films, and the like.

The coating device520may be any suitable device for applying any suitable RSA material20including, but not limited to, a slot-die coating, a slide coating, curtain coating, gravure coating, and the like. Similarly, the curing provided by the curing device530may be by any suitable means including, but not limited to, heating, ultraviolet curing, and the like. As with the other data storage devices constructed, other steps in the method may include, for example, adhering the stacked film structure to one or more substrate layers, cutting the device to a predefined size and shape, and/or applying various coatings as discussed herein.

Further, while embodiments illustrated and described herein may be used in the area of optical data storage and retrieval, aspects of the invention are not limited as such. The components, devices incorporating said components, and methods of manufacture may be used in other technical areas and for other technical endeavors including, but not limited, other non-linear optical uses such as reprogrammable Bragg reflectors.

Therefore, according to one embodiment of the present invention, a component comprises a stacked film structure comprising a plurality of layers inert to light having a first refractive index interleaved with a plurality of layers inert to light having a second refractive index, wherein in the first refractive index is different than the second refractive index; and a plurality of layers comprising a reverse saturable absorber (RSA) material, wherein each of the plurality of layers is located between one of the plurality of layers inert to light having the first refractive index and one of the plurality of layers inert to light having the second refractive index.

In accordance with another aspect of the invention, a method of manufacture comprises method of manufacture comprises: providing a plurality of layers inert to light having a first refractive index; providing a plurality of layers inert to light having a second refractive index, wherein the first refractive index is different than the second refractive index; applying a reverse saturable absorber (RSA) material to at least one of the layer inert to light having the first refractive index and the layer inert to light having the second refractive index; and, adhering the plurality of layers inert to light having the first refractive index to the plurality of layers inert to light having the second refractive index, so that the plurality of layers inert to light having the first refractive index and the plurality of layers inert to light having the second refractive index are interleaved, thereby forming a component having the RSA material located between the layer inert to light having the first refractive index and the layer inert to light having the second refractive index.

According to another embodiment of the present invention, a component comprises: a stacked film structure comprising a plurality of first layers inert to light interleaved with a plurality of second layers inert to light, further wherein the plurality of second layers are doped with a reverse saturable absorber (RSA) material.

According to another embodiment of the present invention, a method of manufacture comprises: providing a plurality of layers inert to light having a first refractive index; providing a plurality of layers inert to light having a second refractive index, said plurality of layers having the second refractive index further including a reverse saturable absorber (RSA) material doped therein; and, adhering the plurality of layers inert to light having the first refractive index to the plurality of layers inert to light having the second refractive index, so that the plurality of layers inert to light having the first refractive index and the plurality of layers inert to light having the second refractive index are interleaved, thereby forming a stacked component having the doped RSA material-laden layers located between the layer inert to light having the first refractive index.

While only certain features of the invention have been illustrated and/or described herein, many modifications and changes will occur to those skilled in the art. Although individual embodiments are discussed, the present invention covers all combination of all of those embodiments. It is understood that the appended claims are intended to cover all such modification and changes as fall within the intent of the invention.