FIELD OF THE INVENTION

Embodiments of the invention relate to generating antireflective coatings for polymeric substrates using glancing angle deposition or other process, apparatuses used to generate such coatings, the formed coatings, substrates having such coatings, and innovations related thereto.

BACKGROUND OF THE INVENTION

Examples of conventional antireflection coatings may be understood from U.S. Patent Publ. No. 2006/0099396, U.S. Patent Publ. No. 2010/0259823, U.S. Patent Publ. No. 2013/0271843, U.S. Patent Publ. No. 2014/0202984, U.S. Patent Publ. No. 2014/0374377, U.S. Patent Publ. No. 2016/0233825, U.S. Pat. Nos. 7,914,852, and 5,900,288. Current broadband antireflection (AR) coatings can play a role in applications ranging from optical lenses and imaging systems to displays, solar concentrators, and/or photovoltaics.

Conventional antireflection systems and methods may not be well-suited for some optical systems (e.g., plastic optics). This may be due to poor adhesion, large thermal expansion mismatch, inherent limitations in coating process temperature, and/or other deficiencies. In addition, conventional antireflection systems and methods may operate at limited bandwidths (e.g., to the visible spectral range). Moreover, the complexity (e.g., most can include use of four or more layers) of traditional systems and methods may provide additional obstacles.

SUMMARY OF THE INVENTION

Anti-reflective coatings and methods of preparing such coatings are disclosed herein. Some embodiments can include nanostructuring the coating to grade the refractive index thereof. Some embodiments can include grading the refractive index via low pressure and/or low temperature techniques. An embodiment of the coating may be applied to a substrate for an optical system (e.g., a curved lens, a Fresnel lens, etc.). An embodiment of the coating may exhibit curved surface compatibility with the substrate. Some embodiments may include glancing angle deposition (GLAD) to generate an embodiment of the coating on an embodiment of the substrate. Some embodiments can include a selective dissolution technique to generate an embodiment of the coating on an embodiment of the substrate. Some implementations may facilitate generating a fluoropolymer coating applied to a polymeric substrate that may be composed of a polymeric material such as, for example, acrylic material, polycarbonate material, Cyclo Olefin Polymeric material (e.g. Zeonex brand cyclo olefin polymeric material), cyclic olefin copolymeric material (e.g. TOPAS brand cyclic olefin copolymers), polyethylene material, or a plastic material.

Embodiments can further include an optical component that may include an embodiment of the coating applied to at least a portion of an embodiment of the substrate configured for use as an optical element (e.g., a lens). This may be done to modify the optical transmittance through the substrate. An embodiment of the optical component may exhibit broadband, omnidirectional antireflective performance and/or extreme durability. The deposition of the coating may be performed such that the coating material is cleaved into molecular fragments that subsequently diffuse into the polymer substrate's surface and then re-polymerizes in interlocking fashion with the polymer chains of the polymer substrate at the surface of the substrate to be coated with the coating. The diffusion and re-polymerization may occur within a depth extending from the outer surface into the substrate (e.g. extending from the outer surface of the substrate into the first 1 micrometer (μm) of the substrate, which can be considered as extending from the surface into a depth of 1 μm into the substrate, extending from the outer surface of the substrate into the first 10-50 nanometers (nm) of the substrate, which can be considered as extending from the outer surface into a depth of 10-50 nm of the substrate, etc.).

In at least one embodiment, a method of generating an antireflective coating can include forming a coating on a surface of a polymeric substrate via a deposition process. The forming of the coating onto the surface of the substrate can occur such that the coating material is vaporized to form chain fragments of the coating material during vaporization of the coating material, the vaporized chain fragments are subsequently diffused into the surface of the polymeric substrate to a depth into the surface of the substrate as layers of the chain fragments are applied onto the surface of the substrate, and the chain fragments diffused into the substrate are subsequently repolymerized to interlock with polymer chains of the substrate.

In some embodiments, the coating material can include a fluoropolymer. In some embodiments, the coating material can include a polymetric material. In some embodiments, the substrate can be plastic, acrylic or polycarbonate. In some embodiments, the substrate can be curved. In some embodiments, the substrate can be a curved lens. In some embodiments, the substrate can be a Fresnel lens. In some embodiments, the deposition process can be a glancing angle deposition (GLAD) process. In some embodiments, the GLAD process can include maintaining the substrate at a temperature that is below the glass transition temperature of the substrate. In some embodiments, vaporization of the coating material occurs via evaporation of the coating material. In some embodiments, the substrate can be a lenslet array.

In at least one embodiment, an optical component can include a substrate configured for use as an optical element, the substrate having a coating formed on at least a portion of a surface of the substrate. The coating can be formed by an embodiment of the methods disclosed herein.

In at least one embodiment, a method of generating an antireflective coating can involve forming a layer of material on a surface of a polymeric substrate via a co-evaporation process. The layer of material can include a first material and a second material. The first material can be a coating. The second material can be a material that is dissolvable by a solvent without dissolving the first material. Forming the layer of material onto the surface of the substrate can occur such that the first material and the second material are vaporized and co-deposited onto the surface of the substrate, wherein the first material re-polymerizes to form a continuous, nanoscale polymer chain network. The method can further involve exposing the second material deposited on the substrate to the solvent for dissolving at least a portion of the second material deposited on the surface of the substrate to remove the second material from the substrate and remove the second material from the first material. Dissolving at least a portion of the second material can include removing all or 100% of the second material, removing 95% of the second material (or any percent within a range of 100% to 95%), removing 90% of the second material (or any percent within a range of 100% to 90%), removing 85% of the second material (or any percent within a range of 100% to 85%), removing 80% of the second material (or any percent within a range of 100% to 80%), removing 75% of the second material (or any percent within a range of 100% to 75%), removing 70% of the second material (or any percent within a range of 100% to 70%), removing 65% of the second material (or any percent within a range of 100% to 65%), removing 60% of the second material (or any percent within a range of 100% to 60%), removing 55% of the second material (or any percent within a range of 100% to 55%), removing 50% of the second material (or any percent within a range of 100% to 50%), removing 45% of the second material (or any percent within a range of 100% to 45%), removing 40% of the second material (or any percent within a range of 100% to 40%), removing 35% of the second material (or any percent within a range of 100% to 35%), removing 30% of the second material (or any percent within a range of 100% to 30%), removing 25% of the second material (or any percent within a range of 100% to 25%), removing 20% of the second material (or any percent within a range of 100% to 20%), removing 15% of the second material (or any percent within a range of 100% to 15%), removing 10% of the second material (or any percent within a range of 100% to 10%), removing 5% of the second material (or any percent within a range of 100% to 5%), or removing or any percent within a range of 100% to 0.01%).

In some embodiments, the second material can include 4,4-bis[N-(1-naphthyl-1)-N-phenyl-amino]-biphenyl (NPD). In some embodiments, the solvent can be acetone or include acetone. In some embodiments, the layer of material can include a mixture including the first material at a first vol % and the second material at a second vol %. In some embodiments, the solvent can be at least one of acetone, isopropanol, tetrahydrafuran, chlorobenzene, toluene, and cyclohexane. In some embodiments, the substrate can be plastic, acrylic or polycarbonate. In some embodiments, the substrate can be curved. In some embodiments, the substrate can be at least one of a curved lens, a Fresnel lens, and a lenslet array.

In at least one embodiment, an optical component can include a substrate configured for use as an optical element, the substrate having a coating formed on at least a portion of a surface of the substrate. The coating can be formed by an embodiment of the methods disclosed herein.

In some embodiments, an optical component can include a substrate configured for use as an optical element, the substrate having the coating formed on at least a portion of a surface of the substrate. The coating can include the layer of material being formed by an embodiment of the methods disclosed herein.

Further features, aspects, objects, advantages, and possible applications of the present invention will become apparent from a study of the exemplary embodiments and examples described below, in combination with the Figures, and the appended claims.

