Abstract: An optical film for a back light unit that includes an array of light emitting diodes. The optical film includes a substrate, and a plurality of regions of spatially modulated microstructures on at least one side of the substrate. The spatially modulated microstructures have different sizes and/or shapes configured to create a gradient structure within each region. The gradient structure within each region is constructed and arranged to cause more spreading of light when positioned directly above an individual light emitting diode and less spreading of light at locations not directly above an individual light emitting diode. Within the back light unit, the gradient structure converts light beams emitted by the respective light emitting diode at different angles into a more uniform and higher on-axis luminance upon exiting the back light unit.

Abstract: A cemented lens includes a first optical element, a second optical element, a third optical element sandwiched between the first optical element and the second optical element and containing resin, a light shielding layer covering a surface of the third optical element that is in contact with neither the first optical element nor the second optical element, and a porous layer covering at least a part of the light shielding layer.

Abstract: According to one embodiment, a method for producing a coated glass article may include applying an anti-reflective coating onto a glass substrate. The glass substrate may include a first major surface, and a second major surface opposite the first major surface. The anti-reflective coating may be applied to the first major surface of the glass substrate. A substrate thickness may be measured between the first major surface and the second major surface. The glass substrate may have an aspect ratio of at least about 100:1. The coated glass article may have a reflectance of less than 2% for all wavelengths from 450 nanometers to 700 nanometers. The anti-reflective coating may include one or more layers. The cumulative layer stress of the anti-reflective coating may have an absolute value less than or equal to about 167,000 MPa nm.

Abstract: Embodiments of articles with optical coatings are described herein. According to one embodiment, an article may comprise a substrate having a major surface, and an optical coating disposed on the major surface and forming an anti-reflective surface, the optical coating comprising an anti-reflective coating. The article may exhibit a maximum hardness of about 12 GPa or greater as measured on the anti-reflective surface by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater. The article may exhibit a single side average light reflectance measured at the anti-reflective surface of about 8% or less over an optical wavelength regime in the range from about 400 nm to about 800 nm. The article may exhibit an average light transmission of about 90% or greater over an optical wavelength regime in the range from about 400 nm to about 800 nm.

Abstract: An optical element includes a transmissive layer arranged on a substrate and made up of discrete volumes of first and second optical media. The layer is between the substrate and another optical medium. The volumes are arranged so that, averaged over a wavelength's distance of an incident optical signal, the effective reflectivities of the two surfaces of the transmissive layer and the effective double-pass phase delay through the transmissive layer are substantially constant across the transmissive layer. The reflectivities and phase delay result in net power reflectivity that differs from that of the substrate in direct contact with the other optical medium. The transmissive layer can be arranged as an anti-reflection layer.

Abstract: The invention relates to transparent multilayer structures and glazings or glazing elements comprising said multilayer structures, which are suitable for screening an indoor space from a radiation source, comprising, in this order a) optionally a protective layer a, b) a substrate layer based on a thermoplastic polymer, especially an aromatic polycarbonate, having a luminous transmittance in the range of 380 to 780 nm of at least 0.3%, determined at a layer thickness of 4 mm according to DIN ISO 13468-2:2006 (D65, 10°), and a TDS value of less than 40%, determined according to ISO 13837:2008 at a layer thickness of 4 mm, the substrate layer containing at least 0.001 wt.

Abstract: A display panel includes: a plurality of light emitting units each having a light emitting side and a back side; a transparent substrate disposed over the light emitting side of the light emitting unit; a transparent film disposed over a side of the transparent substrate opposing the light emitting unit, wherein: the transparent film has an effective refractive index smaller than a refractive index of the transparent substrate; and the transparent film has a position-dependent refractive index progressively smaller along a light emitting direction from the light emitting unit.

Abstract: In a foldable display device according to an embodiment, a groove with a zigzag pattern is formed on a surface of an optical element. The optical element is bonded using an adhesive layer having a low modulus to mitigate stress and impact due to folding in a folding area of the device. According to an embodiment, a foldable display device includes: a panel assembly divided into a folding area and a non-folding area; and an optical element on the panel assembly including grooves with a zigzag pattern patterned on an upper surface of the optical element.

Abstract: An optical module 100 includes a first substrate 11 including an optical filter device 7 having a wavelength variable interference filter 110 built therein, a second substrate 12 including a light receiving element 17, and a first supporter 16 that mechanically or electrically joins the first substrate 11 and the second substrate 12 to each other, in which the wavelength variable interference filter 110 and the light receiving element 17 are disposed to face each other by the first supporter 16, and the first substrate 11 and the second substrate 12 are joined to each other by the first supporter 16 with a gap S1 in which a circuit element 21 is mountable.

Abstract: Embodiments of a scratch-resistant and optically transparent material comprising silicon, aluminum, nitrogen, and optionally oxygen are disclosed. In one or more embodiments, the material exhibits an extinction coefficient (k) at a wavelength of 400 nm of less than about 1×10?3, and an average transmittance of about 80% or greater, over an optical wavelength regime in the range from about 380 nm to about 780 nm, as measured through the material having a thickness of about 0.4 micrometer. In one or more embodiments, the material comprises an intrinsic maximum hardness of about 12 GPa or greater as measured on a major surface of the material having a thickness of about 400 by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater, low compressive stress and low roughness (Ra). Articles and devices incorporating the material are also disclosed.

Abstract: A light diffraction film includes a transparent substrate; and a light diffraction layer containing a binder resin and particles, in which an average primary particle diameter of the particles is 1 ?m to 10 ?m, and a coverage of a surface of the transparent substrate covered with the particles is 70% to 90%.

Abstract: A method for creating an enhanced multipaction resistant diamond-like coating (DLC) coating with lower Secondary Electron Emission (SEE) properties is performed on an initial surface by etching a DLC coating deposited on the surface after deposition and optionally creating interlayers to enhance adhesion mechanical properties between the DLC coating and the initial surface.

Abstract: An optical filter may include a substrate, a first mirror that includes a first subset of layers of a set of layers, and a second mirror that includes a second subset of layers of the set of layers. The optical filter may include a spacer. The spacer may include a third subset of layers of the set of layers. The set of layers may include a plurality of high refractive index layers associated with a first refractive index and a plurality of low refractive index layers associated with a second refractive index that is less than the first refractive index. The optical filter may be associated with a spectral range from at least approximately 1200 nanometers (nm) to approximately 1900 nm.

Abstract: A coated glass article includes a glass substrate. A coating is formed over the glass substrate. The coating includes a first inorganic metal oxide layer deposited over a major surface of the glass substrate. The first inorganic metal oxide layer has a refractive index of 1.6 or more. A second inorganic metal oxide layer is deposited over the first inorganic metal oxide layer. The second inorganic metal oxide layer has a refractive index which is less than the refractive index of the first inorganic metal oxide layer. A third inorganic metal oxide layer is deposited over the second inorganic metal oxide layer. The third inorganic metal oxide layer has a refractive index of 2.2 or more and the refractive index of the third inorganic metal oxide layer is greater than the refractive index of the second inorganic metal oxide layer. A fourth inorganic metal oxide layer is deposited over the third inorganic metal oxide layer.

Abstract: The disclosure relates to detecting and clearing debris from a sensor window. For instance, a system may include the sensor window and one or more processors. The sensor window may include a transparent thin film conductor. The one or more processors may be configured to identify a change in capacitance using the transparent thin film conductor, detect debris on the sensor window using the change in capacitance, and activate a cleaning system in order to clear the detected debris from the sensor window.

Abstract: A Fabry-Perot interference filter includes: a substrate having a first surface and a second surface facing each other; a first layer structure disposed on the first surface; and a second layer structure disposed on the second surface, wherein the first layer structure is provided with a first mirror portion and a second mirror portion facing each other with an air gap therebetween, and a distance between the first mirror portion and the second mirror portion is varied, and the second layer structure is formed with a separation region separating at least a part of the second layer structure into one side and another side in a direction along the second surface.

Abstract: The invention relates to methods for fabricating antireflective surface structures (ARSS) on an optical element using a three-dimensional film layer applied to the surface of the optical element. The methods beneficially permit materials that do not exhibit local variation in physical and chemical properties to be provided with ARSS. Optical elements having ARSS on at least one surface are also provided.

Abstract: A substrate provided with an anti-reflective coating where the anti-reflective coating is made up of a layer of nanostructures. The nanostructures may be formed by depositing a material such as SiO2 and then using a process such as reactive ion etching in conjunction with an inductively coupled plasma source. Other aspects of the fabrication process are also disclosed.

Abstract: Embodiments of articles with optical coatings are described herein. According to one embodiment, an article may comprise a substrate having a major surface, and an optical coating disposed on the major surface and forming an anti-reflective surface, the optical coating comprising an anti-reflective coating. The article may exhibit a maximum hardness of about 12 GPa or greater as measured on the anti-reflective surface by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater. The article may exhibit a single side average light reflectance measured at the anti-reflective surface of about 8% or less over an optical wavelength regime in the range from about 400 nm to about 800 nm. The article may exhibit an average light transmission of about 90% or greater over an optical wavelength regime in the range from about 400 nm to about 800 nm.

Abstract: An absorption layer 13 is formed above a substrate 11. The transmittance of the absorption layer 13 varies at different locations of the substrate 11. The absorption layer 13 includes a first material and a second material that have an absorption coefficient that depends on a wavelength. The extinction coefficient of the absorption layer 13 is equal to or less than 0.5 at a wavelength of 400 nm to 700 nm.

Abstract: There is provided a new and improved master manufacturing method, master, and optical body enabling more consistent production of optical bodies having a desired haze value, the master manufacturing method including: forming a first micro concave-convex structure, in which an average cycle of concavities and convexities is less than or equal to visible light wavelengths, on a surface of a base material body that includes at least a base material; forming an inorganic resist layer on the first micro concave-convex structure; forming, on the inorganic resist layer, an organic resist layer including an organic resist and filler particles distributed throughout the organic resist; and etching the organic resist layer and the inorganic resist layer to thereby superimpose and form on the surface of the base material a macro concave-convex structure and a second micro concave-convex structure.

Abstract: A laser pulse includes a flat top shape. Another aspects provides a method and system for creating laser pulse amplification with a flat top and/or square shape, by only using phase modulation. In yet another aspect, a method and system create a flat top and/or square-shaped laser pulse in a reversible manner such that the stretched spectrum can be recompressed to their original duration with essentially no loss of pulse energy. A further aspect includes a method of making a fixed optic capable to creating flat top or square pulse amplification.

Abstract: Provided is a substrate with low-reflection property having small changes in reflected light and color between a principal surface and a side surface when it is visually recognized, and including high displayability in a front substrate or the like which is disposed while exposing the side surface. A substrate 10 with low-reflection property includes: a transparent substrate 11; a first low-reflection film 12 provided on one principal surface of the transparent substrate 11; and a second low-reflection film 13 provided on a side surface of the transparent substrate 11, wherein luminous reflectance Rtot of the first low-reflection film 12 provided on one principal surface is 1.5% or less, luminous reflectance Rs of the second low-reflection film 13 provided on the side surface is 2.5% or less, chromaticity a* is 0 to 4, and chromaticity b* is 3 to 9.

Abstract: An optical image capturing module is provided, including a circuit assembly and a lens assembly. The circuit assembly may include a circuit substrate, a plurality of image sensor elements, a plurality of signal transmission elements, and a multi-lens frame. The image sensor elements may be connected to the circuit substrate. The signal transmission elements may be electrically connected between the circuit substrate and the image sensor elements. The multi-lens frame may be manufactured integrally, be covered on the circuit substrate, and surround the image sensor elements and the signal transmission elements. The lens assembly may include a lens base and a fixed-focus lens assembly. The lens base may be fixed to a multi-lens frame. The fixed-focus lens assembly may have at least two lenses with refractive power.

Abstract: The present application relates to gas barrier film having excellent adhesive strength and a method of manufacturing the same. Particularly, the present application is directed to providing a gas barrier film having excellent adhesion performance between an inorganic layer and a protective coating layer under harsh conditions by protective coating layer including inorganic nano particles surface-modified with organic silane on the inorganic layer.

Abstract: Provided is a coating base material having a new configuration capable of enhancing the durability of a coating regardless of the adhesion strength of a primer. A coating base material 1 whose surface is subjected to application of a coating includes: a mesh-like valley portion 2 formed on the surface; and a plurality of island portions 3 formed on the surface and surrounded by the valley portion 2. Each island portion 3 has a crater-like recess 4 formed on an upper surface thereof.

Abstract: Described herein are antimicrobial articles having improved antimicrobial efficacy and antireflective properties. Further described are methods of making and using the improved articles. The antimicrobial articles generally include an antimicrobial element and an antireflective element. The antireflective element, in some cases, can be disposed directly on a glass, glass-ceramic or ceramic substrate and the antimicrobial element is disposed on the antireflective element. The article can exhibit a reflectance of about 4% or less (and less than 1% in some cases) in the range of about 425 nm to about 725 nm. Further, the article can be characterized with an antimicrobial efficacy by exhibiting at least a 2 log reduction in a concentration of at least Staphylococcus aureus, Enterobacter aerogenes, and Pseudomonas aeruginosa bacteria under a Modified EPA Copper Test Protocol.

Abstract: Edge-emitting laser diodes having mirror facets include passivation coatings that are conditioned using an ex-situ process to condition the insulating material used to form the passivation layer. An external energy source (laser, flash lamp, e-beam) is utilized to irradiate the material at a given dosage and for a period of time sufficient to condition the complete thickness of passivation layer. This ex-situ laser treatment is applied to the layers covering both facets of the laser diode (which may comprise both the passivation layers and the coating layers) to stabilize the entire facet overlay. Importantly, the ex-situ process can be performed while the devices are still in bar form.

Abstract: A method and apparatus for reducing ghost images in a laser imaging system. The method includes, positioning an absorptive neutral density filter, having an optical density (OD) of at least ?1, between a pixelated detector and a laser source. The method further includes, emitting a laser beam, from the laser source onto the absorptive neutral density filter, transmitting a portion of the light incident upon a first surface of the absorptive neutral density filter to a second surface of the absorptive neutral density filter, reflecting a portion of light incident upon the second surface of the absorptive neutral density filter and absorbing the reflected portion of light, by the absorptive neutral density filter, to reduce ghost images at the pixelated detector.

Abstract: A laminated film appropriate as a PPF material which has a three-layer structure in which a top coating layer including a urethane acrylate cured product, a substrate layer including polycarbonate thermoplastic polyurethane, and an adhesive layer including a pressure sensitive adhesive are in contact in that order. Preferably, the top coating layer includes a unit derived from ?-methacryloxypropylhepta(trifluoropropyl)-T8-silsesquioxane.

Abstract: The invention is based on the idea of providing a light emitting diode (OLED) device which contains a substrate with a photonic crystal, whereby the formed film structure induces enhancement of the liberation of photons trapped inside the light emitting device structure. The photonic crystal structure is a film structure on a substrate produced using a combination of high and low refractive index materials, at least one of the materials being based on a liquid phase deposited metal-oxide or metalloid oxide material. By means of the invention light trapped due to total internal reflection in a waveguide acting light emitting structure can be extracted efficiently from the device by introducing the photonic crystal device structure between the substrate and conductive anode layer.

Abstract: Provided a spectacle lens including a lens base material and a multilayer film provided on each surface of an eyeball-side surface and an object-side surface of the lens base material, in which a mean reflectance RB(object) in a wavelength range of 430 to 450 nm measured on the object-side surface of the spectacle lens is equal to or more than 1.00%, and a mean reflectance RUV(eye) in a wavelength range of 280 to 380 nm measured on the eyeball-side surface of the spectacle lens is less than or equal to 15.00%.

Abstract: A method of making a coated article includes forming a first coating over a first surface of a substrate; and forming a second coating over a second surface of the substrate. The second coating includes a first conductive layer including tin oxide and at least one material selected from the group consisting of tungsten, molybdenum, and niobium.

Abstract: Optical constructions are disclosed. A disclosed optical construction includes a reflective polarizer layer, and an optical film that is disposed on the reflective polarizer layer. The optical film has an optical haze that is not less than about 50%. Substantial portions of each two neighboring major surfaces in the optical construction are in physical contact with each other. The optical construction has an axial luminance gain that is not less than about 1.2.

Abstract: Low loss, high reflectivity wide band mirror films provide a desired mix of specular reflection and diffuse reflection or scattering to provide semi-specular reflectivity. The mirror films generally include both a specularly reflective multilayer optical film (MOF) having a wide reflection band, and a scattering layer. In some cases a low refractive index TIR layer is sandwiched between the MOF and the scattering layer. In other cases the scattering layer contacts the MOF directly. In embodiments that include the TIR layer, the TIR layer preferably has a nanovoided morphology and includes a plurality of particles and a polymer binder. In embodiments wherein the scattering layer contacts the MOF directly, the scattering layer preferably also has a nanovoided morphology and includes a plurality of particles and a polymer binder.

Abstract: A method of masking glass in an ion exchange bath includes applying a dissolvable sealant to a cover material, adhering the cover material to a glass part to form a mask on the glass part, immersing the glass part into an ion exchange bath. removing the glass part from the ion exchange bath, and using a solvent to dissolve the sealant and the cover material from the glass part. A mask on glass having a piece of glass, and a dissolvable sealant on a cover material, the dissolvable sealant comprising an inorganic material and a silicate, the dissolvable sealant between the cover material and the piece of glass.

Abstract: Disclosed herein are various embodiments for laser arrays that include graphene lens structures located on laser-emitting semiconductor structures. In an example embodiment, an apparatus comprising (1) a laser-emitting epitaxial structure having a front and a back, wherein the laser-emitting epitaxial structure is back-emitting, and (2) a graphene lens structure located on the back of the laser-emitting epitaxial structure. Photolithography processes can be used to deploy the graphene lens structures on the laser structures.

Abstract: Embodiments of a scratch-resistant and optically transparent material comprising silicon, aluminum, nitrogen, and optionally oxygen are disclosed. In one or more embodiments, the material exhibits an extinction coefficient (k) at a wavelength of 400 nm of less than about 1×10?3, and an average transmittance of about 80% or greater, over an optical wavelength regime in the range from about 380 nm to about 780 nm, as measured through the material having a thickness of about 0.4 micrometer. In one or more embodiments, the material comprises an intrinsic maximum hardness of about 12 GPa or greater as measured on a major surface of the material having a thickness of about 400 by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater, low compressive stress and low roughness (Ra). Articles and devices incorporating the material are also disclosed.

Abstract: An optical filter includes: a first substrate; a second substrate opposed to the first substrate; a first reflecting film provided to the first substrate; a second reflecting film provided to the second substrate and opposed to the first reflecting film; a first electrode provided to the first substrate in a peripheral area of the first reflecting film; a second electrode provided to the first substrate in a peripheral area of the first electrode; a third electrode provided to the second substrate and opposed to the first electrode; and a fourth electrode provided to the second substrate and opposed to the second electrode.

Abstract: Embodiments of the present technology include thin coating methods for graphene and/or stanene metal composites. An example composite is created by depositing a material including any of graphene and stanene onto a porous metal foam substrate, compressing the porous metal foam the deposited material to form a graphene-metal composite, and depositing a thin metal coating on an outer surface of the porous metal foam substrate or an outer surface of deposited material using any of physical vapor deposition and chemical vapor deposition.

Abstract: An apparatus (60) for adjusting an intensity of radiation. The apparatus comprises a grating (61) for receiving a radiation beam (Ba) and for directing at least a portion of the radiation beam in a first direction in the form of a first reflected radiation beam (Ba0), and one or more first actuators operable to rotate the grating to adjust a grazing angle between the radiation beam and a surface of the grating so as to vary an intensity of the reflected radiation beam.

Abstract: An optical element comprises an antireflective layer that is disposed on and in contact with a substrate. The antireflective layer has a refractive index of greater than 1 to less than 1.41 and has a pore size ranging from greater than 0 to less than 300 nm. The antireflective layer includes an outermost surface having a water contact angle ranging from greater than or equal to 70° to less than or equal to 120° as determined using ASTM 5946-04.

Abstract: An optical interference coating with reduced back reflectance for 3D glasses based on colour separation has a substantial transmittance at one or more passbands over the visible spectral range in order to view the desired left (right) eye image and a substantial reflectance and absorption at one or more different blocking bands over the visible spectral range in order to block the undesired right (left) eye image while simultaneously reducing the back reflectance of visible light towards the viewer's eye. The thicknesses and materials are chosen such that the left eye reduced back reflectance 3D coated lens transmits the desired left eye image and blocks the right eye image while the right eye reduced back reflectance 3D coated lens transmits the desired right eye image and blocks the left eye image so that a 3D image can be viewed whilst substantially reducing distracting back reflections from the coated lenses.

Abstract: A photovoltaic element comprises a semiconductor structure comprising a first layer comprised of a first semiconductor material with minimum electromagnetic damping and a second layer comprised of a second semiconductor material with electromagnetic damping. An upper plane of the first layer comprises an incidence plane of an electromagnetic wave onto the semiconductor structure and the second layer continues beyond the first layer in a direction of propagation of electromagnetic radiation to receive at least a portion of the electromagnetic radiation having passed through the first layer. The photovoltaic element further comprises at least one resonator comprising a first part extending along the upper plane of the first layer and a second part extending within the first layer and the second layer. The reference electrode bordering at least a portion of the second layer is coupled to the second layer in the direction of propagation of the electromagnetic wave.

Abstract: The present invention provides a TiO2-based coagulant and use thereof. The TiO2-based coagulant is obtained by the following steps: uniformly mixing acetylacetone and ethanol and dropwise adding titanium tetrachloride to obtain a solution A; mixing deionized water and ethanol to obtain a solution B; dropwise adding solution B to solution A; stirring to obtain a sol, and then aging the sol to constant weight to obtain the TiO2-based coagulant. The TiO2-based coagulant can be used for treating waste water and algae-laden water. The TiO2-based coagulant exhibits good coagulation effects and high stability, solves the problem of too low effluent pH caused by strong inorganic titanate acidity and is favorable to the subsequent treatment of waste water.

Abstract: Certain example embodiments of this invention relate to articles including anticondensation and/or low-E coatings that are exposed to an external environment, and/or methods of making the same. In certain example embodiments, the anti condensation and/or low-E coatings may be survivable in an outside environment. The coatings also may have a sufficiently low sheet resistance and hemispherical emissivity such that the glass surface is more likely to retain heat from the interior area, thereby reducing (and sometimes completely eliminating) the presence condensation thereon. The articles of certain example embodiments may be, for example, skylights, vehicle windows or windshields, IG units, VIG units, refrigerator/freezer doors, and/or the like.

Abstract: The present invention provides a substrate with an antireflection layer not only which is excellent in the antireflection properties but also which has high water repellency and oil repellency and favorable oil and fat stain removability, and a display device provided with a substrate with an antireflection layer. A substrate with an antireflection layer, which comprises an antireflection layer on at least one surface of the substrate, wherein the antireflection layer contains a silica porous film having fluorinated organic groups, and the surface of the antireflection layer on the opposite side from the substrate has an element number ratio F/Si of at least 1 as obtained from the peak height of F1s and the peak height of Si2p in surface analysis by scanning X-ray photoelectron spectroscopy (ESCA) and has an arithmetic mean roughness (Sa) of at most 3.0 nm.

Abstract: The present invention discloses a coated narrow-band filter having an absorbent material. Two sides of the substrate are respectively an A-side and a B-side, a cut-off layer is coated or screen printed on the A-side, wherein lights having a wavelength within a first band are allowed to pass through the cut-off layer. The substrate is an absorbent layer, or an absorbent layer is provided on the B-side of the substrate. The absorbent layer is made of an absorbent material, lights having a wavelength within a second band are allowed to pass through the absorbent layer. The first band partially overlaps with the second band. For processing convenience, the coated narrow-band filter having an absorbent material is provided at different angles and with small angle of incidence.

Abstract: This invention relates to a coated article including a low-emissivity (low-E) coating. In certain example embodiments, the low-E coating is provided on a substrate (e.g., glass substrate) and includes at least first and second infrared (IR) reflecting layers (e.g., silver based layers) that are spaced apart by contact layers (e.g., NiCr based layers) and a dielectric layer of or including a material such as silicon nitride. In certain example embodiments, the coated article has a low visible transmission (e.g., no greater than 60%, more preferably no greater than about 55%, and most preferably no greater than about 50%).

Abstract: The present invention aims to provide a polyrotaxane-containing composition having excellent transparency. The present invention relates to a polyrotaxane-containing composition including: a polyrotaxane that has a cyclic molecule, a linear molecule threading through a cavity of the cyclic molecule in a skewered manner, and capping groups capping both ends of the linear molecule; and an alkyl (meth) acrylate that has a C4-C18 alkyl group, the polyrotaxane having at least one cyclic molecule that has a C4-C18 alkyl group.