Spectrally engineered solar hydrogen production system

Abstract

A solar-driven opto-electrolysis hydrogen production system configured to convert light and water into hydrogen is disclosed. The system includes a solar radiation collection assembly, an optical transmission network, and one or more opto-electrolysis light rods positioned within a reactor containing water. Each light rod includes an inner optical core, a cladding, and a porous layer comprising photocatalytic centers configured to generate hydrogen upon illumination. The inner optical core contains spectral conversion additives that modify incident solar radiation such that emitted wavelengths overlap an absorption band of the photocatalytic centers. In certain embodiments, the porous layer comprises a monolithic porous structure formed around the cladding with pore characteristics selected to permit diffusion of water and removal of evolved hydrogen. A plurality of light rods may be arranged in an array to enable scalable hydrogen production.

Description

[0001] SPECTRALLY ENGINEERED SOLAR HYDROGEN PRODUCTION SYSTEM

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of U.S. Provisional Patent Application No.

[0004] 63 / 764,152, filed on February 27, 2025, entitled “Opto-Electrolysis Hydrogen Plant,” the entire disclosure of which is hereby incorporated by reference herein in its entirety for all purposes

[0005] FIELD OF THE INVENTION

[0006] The present disclosure relates generally to hydrogen production systems. More specifically, the disclosure relates to optical power driven hydrogen generation systems that utilize light transmitted through optical fibers to activate photocatalytic structures within a reactor to produce hydrogen from water. The disclosure further relates to spectrally engineered optical components, fiber based light distribution architectures, porous catalytic layers formed around optical fibers, and modular reactor assemblies for scalable hydrogen production.

[0007] BACKGROUND OF THE INVENTION

[0008] Hydrogen is widely used as a chemical feedstock, energy carrier, and fuel in industrial, transportation, and energy storage applications. Solar-driven hydrogen production has been investigated as a pathway toward reducing reliance on fossil fuels and decreasing greenhouse gas emissions. In solar-based systems, incident sunlight is used to activate photocatalytic materials capable of splitting water into hydrogen and oxygen. Sunlight contains a broad electromagnetic spectrum, including ultraviolet (UV), visible, and infrared (IR) wavelengths. Many photocatalytic materials, however, absorb and utilize only a limited portion of this spectrum. As a result, significant fractions of the incident solar energy remain unused.

[0009] Ultraviolet light may exceed the optimal absorption range of certain catalysts, while infrared light may pass through the system without contributing to hydrogen production. This spectral mismatch between the solar radiation spectrum and the absorption characteristics of photocatalytic centers reduces overall system efficiency. Existing solar hydrogen systems typically rely on direct irradiation of photocatalytic surfaces or bulk photoreactive materials.These systems may suffer from inefficient light capture, transmission losses, limited control over spectral distribution, non-uniform light intensity within reactors, and suboptimal interaction between light and catalyst. In particular, conventional approaches do not adequately address the problem of converting non-optimal solar wavelengths into wavelength ranges that correspond to peak absorption regions of selected photocatalytic centers.

[0010] Upconversion and downconversion materials have been studied for modifying the wavelength of incident light. Upconversion may convert lower-energy photons, such as nearinfrared light, into higher-energy visible or ultraviolet light. Downconversion may convert higher-energy ultraviolet photons into visible wavelengths. However, prior systems have not effectively integrated spectral conversion materials into solar hydrogen production architectures in a manner that systematically matches the emitted wavelength distribution to the absorption characteristics of specific photocatalytic centers used for water splitting. Accordingly, there remains a need for solar hydrogen production systems that efficiently collect and concentrate sunlight, convert non-optimal portions of the solar spectrum into wavelengths that align with the absorption bands of selected photocatalytic centers, distribute spectrally modified light within scalable reactor architectures, and improve hydrogen generation efficiency through intentional spectral matching and optimized optical management.

[0011] SUMMARY OF THE INVENTION

[0012] The present disclosure provides solar-driven opto-electrolysis systems for producing hydrogen from water using spectrally engineered optical energy delivery. In certain embodiments, sunlight is collected and transmitted through an optical transmission network to one or more opto-electrolysis light rods positioned within a reactor containing water. Each opto-electrolysis light rod may comprise an inner optical core, a surrounding cladding, and a porous layer containing photocatalytic centers configured to convert water into hydrogen in the presence of light. The inner optical core may include one or more spectral conversion additives configured to modify a wavelength distribution of incident light. In certain embodiments, the spectral conversion additives comprise upconversion materials, downconversion materials, or combinations thereof. The spectral conversion additives maybe selected such that light emitted from the inner optical core overlaps at least partially with an absorption band of the photocatalytic centers contained within the porous layer. In various embodiments, the inner optical core may further include light scattering centers configured to direct spectrally modified light radially toward the porous layer to enhance photocatalytic interaction. The porous layer may permit diffusion of water and evolved gases while maintaining structural and optical integrity. The disclosure further provides modular reactor element assemblies comprising arrays of opto-electrolysis light rods arranged to distribute optical energy and enable scalable hydrogen production. Multiple reactor element assemblies may be integrated into a reactor core, and optical energy from one or more solar radiation collection assemblies may be delivered through power-over-fiber architectures. The disclosed systems enable coordinated solar light collection, spectral conversion, optical distribution, and photocatalytic hydrogen generation within scalable reactor architectures. In certain embodiments, the porous layer comprises a monolithic porous structure formed around at least a portion of the cladding. The monolithic porous structure may be formed by sol gel processing to produce a silica based porous monolith, or by polymerization in the presence of one or more porogens to produce a polymer based porous monolith. In certain embodiments, pore size and porosity are selected to permit diffusion of water into the porous layer and removal of evolved hydrogen while maintaining internal surface area and optical interaction length to promote absorption of spectrally conditioned photons by photocatalytic centers. In certain embodiments, the system is configured according to coordinated design rules in which dopant emission is selected to overlap photocatalyst absorption, refractive index contrast is configured to promote radial photon delivery, and pore structure is selected to balance mass transport and optical absorption.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 illustrates a cross-sectional view of an opto-electrolysis light rod (OELR) including an inner core, cladding, porous layer, and photocatalytic regions.

[0015] FIG. 2 illustrates a representative cross-sectional light intensity distribution across the optoelectrolysis light rod of FIG. 1.FIG. 3 illustrates a cross-sectional view of a power-over-fiber (PoF) cable configured to transmit optical power.

[0016] FIG. 4A illustrates an opto-electrolysis light rod assembly including a PoF cable optically coupled to an opto-electrolysis light rod.

[0017] FIG. 4B illustrates a reactor element assembly comprising an array of opto-electrolysis light rod assemblies supported by grid structures.

[0018] FIG. 4C illustrates a top view of a cell configured to support an opto-electrolysis light rod assembly.

[0019] FIG. 4D illustrates a grid plate configured to support a plurality of opto-electrolysis light rod assemblies.

[0020] FIG. 5A illustrates a perspective view of a reactor element assembly.

[0021] FIG. 5B illustrates a reactor core comprising a plurality of reactor element assemblies arranged between upper and lower structural plates.

[0022] FIG. 6A illustrates a reactor including a reactor core, fluid management ports, temperature control structures, and optical entry ports.

[0023] FIG. 6B illustrates an opto-electrolysis hydrogen plant including a reactor, hydrogen isolation and purification train, fluid recirculation systems, optical aggregation system, and light source.

[0024] FIG. 7A illustrates a top view of a solar radiation collection assembly (SRCA) including a lens and frame structure.

[0025] FIG. 7B illustrates a rear view of the solar radiation collection assembly showing optical coupling to a power-over-fiber cable.

[0026] FIG. 8A illustrates a side view of a solar radiation collection assembly showing lens positioning and enclosure structure.FIG. 8B illustrates an exploded view of a solar radiation collection assembly including a lens, waveguide, optional collimator, and optical coupling components.

[0027] FIG. 9A illustrates a top view of a panel sub-assembly comprising a plurality of solar radiation collection assemblies.

[0028] FIG. 9B illustrates a bottom view of a panel sub-assembly showing optical coupling components.

[0029] FIG. 10A illustrates an optical power transmission network configured to aggregate optical power from multiple power-over-fiber cables into a high-capacity transmission cable.

[0030] FIG. 10B illustrates a panel sub-assembly coupled to an optical power transmission network.

[0031] FIG. 11A illustrates a top view of a panel comprising multiple panel sub-assemblies.

[0032] FIG. 11B illustrates a bottom view of a panel showing high-capacity optical output cables.

[0033] FIG. 12 illustrates a panel system including a panel mounted on a tracking rack and configured to output bundled high-capacity optical cables.

[0034] DETAILED DESCRIPTION OF THE INVENTION

[0035] In the following description, reference is made to the accompanying drawings that form a part hereof and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other embodiments may be utilized and that structural, compositional, and procedural changes may be made without departing from the scope of the invention. Unless otherwise indicated, like reference numerals refer to like elements.

[0036] FIG. 1 Opto Electrolysis Light Rod (OELR)

[0037] FIG. 1 depicts a cross sectional view of an opto electrolysis light rod (OELR) 100. In certain embodiments, the OELR 100 includes an inner core 101 having an inner core diameter d2. The inner core 101 may include light scattering centers 103 and or upconversion complexes103 and or downconversion complexes 103. In certain embodiments, the OELR 100 further includes a cladding 102 having a cladding diameter d4. The cladding 102 may include light scattering centers 105 and or upconversion complexes 105 and or downconversion complexes 105. In some embodiments, the interface between the inner core 101 and the cladding 102 includes light scattering centers 104 and or upconversion complexes 104 and or downconversion complexes 104. In certain embodiments, the OELR 100 further includes a porous layer 107 having a porous layer thickness tl. The porous layer 107 may have a porosity 108. The porous layer 107 may include surface pores 111 that extend from an exterior surface through at least a portion of the porous layer 107 toward the cladding 102. In some embodiments, the interface between the porous layer 107 and the cladding 102 includes light scattering centers 106 and or upconversion complexes 106 and or downconversion complexes 106. The porous layer 107 may include photocatalytic centers 109, 110. In certain embodiments, photocatalytic centers are incorporated within the porous layer 107 and may be referred to as incorporated photocatalytic centers 109. In certain embodiments, photocatalytic centers are coated and or bonded on surfaces of pores within the porous layer 107 and may be referred to as coated photocatalytic centers 110. The photocatalytic centers 109, 110 may be configured to convert water to hydrogen in the presence of light. In operation, water may diffuse into and out of the porous layer 107, and hydrogen and or oxygen may be produced and may diffuse out of and or through the porous layer 107. In certain embodiments, the porous layer 107 further includes an additional coating 112 that may be referred to as a porous layer coating 112. The porous layer coating 112 may protect the porous layer 107 from degradation, may promote diffusion of water into the porous layer 107, and or may promote diffusion of gas out of the porous layer 107. The porous layer coating 112 may have a porous layer coating thickness t3.

[0038] OELR Core Diameter: The OELR inner core diameter d2 may be between 10 micrometers and 10 millimeters. In certain embodiments, d2 may be between 10 micrometers and 1 millimeter. In certain embodiments, d2 may be between 50 micrometers and 500 micrometers. In certain embodiments, d2 may be between 100 micrometers and 400 micrometers. The selected diameter may depend on optical power density, desired numerical aperture, and reactor packing density.OELR Cladding Outer Diameter: The OELR cladding outer diameter d4 may be between 5 micrometers and 15 millimeters. In certain embodiments, d4 may be between 20 micrometers and 2 millimeters. In certain embodiments, d4 may be between 100 micrometers and 1 millimeter. In certain embodiments, d4 may be between 150 micrometers and 600 micrometers. The cladding thickness may be selected to maintain optical confinement while permitting radial photon leakage in accordance with the escape cone design rule described herein.

[0039] Porous Layer Thickness: The porous layer thickness tl may be between 10 micrometers and 20 millimeters. In certain embodiments, tl may be between 20 micrometers and 5 millimeters. In certain embodiments, tl may be between 50 micrometers and 2 millimeters. In certain embodiments, tl may be between 100 micrometers and 1 millimeter. The porous layer thickness may be selected to provide sufficient optical interaction length for photon absorption while avoiding excessive diffusion resistance or mechanical instability. The refractive index difference between the OELR inner core 101 and the OELR cladding 102 may be expressed as Delta OELR N, where Delta OELR N equals OELR N core minus OELR N cladding. The refractive index of the OELR inner core 101 (OELR N core) may be between 1.35 and 2.10. In certain embodiments, OELRN core may be between 1.44 and 1.60. In certain embodiments, OELRN core may be between 1.60 and 2.00. In certain embodiments, OELR N core may be between 1.70 and 2.05. The refractive index of the OELR cladding 102 (OELRN cladding) may be between 1.30 and 2.00. In certain embodiments, OELRN cladding may be between 1.35 and 1.55. In certain embodiments, OELR N cladding may be between 1.40 and 1.60. Delta OELR N may be between 0.0005 and 0.40. In certain embodiments, Delta OELR N may be between 0.002 and 0.05. In certain embodiments, Delta OELR N may be between 0.02 and 0.20. In certain embodiments, Delta OELR N may be between 0.05 and 0.40. In certain embodiments, the refractive index contrast is selected to provide a numerical aperture between 0.02 and 0.80, and in certain embodiments between 0.05 and 0.60, thereby controlling photon confinement and radial extraction toward porous layer 107. In certain embodiments, Delta OELR N may be positive such that OELR N core exceeds OELR N cladding to provide guided optical propagation. The OELR inner core 101, the OELR cladding 102, the interface between the OELR core 101and the OELR cladding 102, and / or the porous layer 107 may comprise glass, doped glass, rare earth doped glass, metal oxide compositions, polymeric materials, porous monolithic materials, photocatalytic centers, light scattering centers, or combinations thereof.

[0040] FIG. 2 Cross Sectional Light Intensity Distribution

[0041] FIG. 2 depicts a cross sectional light intensity distribution illustration 200. This example depicts an OELR cross section 100 that may be comprised of an OELR inner core 207, 101, an OELR cladding 208, 102, an OELR porous layer 206, 107, and an OELR porous layer coating 205, 112. Although not shown, the OELR may also be comprised of light scattering centers 104 and or upconversion complexes 104 and or downconversion complexes 104 and or porosity 108 and or surface pores 111.

[0042] OELR Porous Layer Outer Diameter: An OELR 100 including porous layer 107 may have an overall outer diameter d5. In certain embodiments, d5 may be between 20 micrometers and 30 millimeters. In certain embodiments, d5 may be between 50 micrometers and 10 millimeters. In certain embodiments, d5 may be between 100 micrometers and 5 millimeters. In certain embodiments, d5 may be between 200 micrometers and 2 millimeters. The overall diameter d5 may be determined by the selected inner core diameter d2, cladding outer diameter d4, and porous layer thickness tl, and may be selected to balance optical power delivery, reactor packing density, fluid flow characteristics, and mechanical stability The cross sectional light intensity distribution illustration 200 may be depicted with an x axis 209 representing radial distance from the center of inner core 101, and a y axis 204 representing relative light intensity expressed as a percentage of maximum intensity within inner core 101. In certain embodiments, 100 percent light intensity corresponds to the maximum optical intensity 202 within inner core 101 prior to radial emission into porous layer 107. As light propagates radially into porous layer 107, light intensity may decrease due to absorption of photons by photocatalytic centers 109, 110. The design of OELR 100 may be configured such that a substantial portion of emitted light is absorbed within porous layer 107 before reaching an outer radial boundary. In certain embodiments, residual light intensity at an outer boundary of porous layer 107 may be less than 10 percent of the maximum inner core intensity. In certain embodiments, residual light intensity at the outer boundary may be lessthan 5 percent. In certain embodiments, residual light intensity may be less than 1 percent. In certain embodiments, residual light intensity may be less than 0.1 percent. The reduction in light intensity from the maximum value to the residual value may be illustrated by light depletion lines 201 and 203.

[0043] FIG. 3 Power Over Fiber (PoF) Cable

[0044] FIG. 3 depicts a cross section of a power over fiber (PoF) cable 300. The PoF cable 300 may be comprised of a PoF inner core 302 with a PoF inner core diameter d6, a PoF cladding 304 with a PoF cladding diameter d7, and or a PoF coating 306. The thickness of the PoF coating 306 may be between 0.01 um and 10 um, 10 um and 100 um, 100 um and 1 mm, 1 mm and 2 mm, 2 mm and 3 mm, or greater than 3 mm. The PoF cable 300 may be comprised of glass, elements, and or coatings. The PoF core 302 may be comprised of glass, elements, germanium, and or coatings. The PoF cladding 304 may be comprised of glass, elements, germanium, and or coatings. The PoF coating 306 may be comprised of a cable and or fiber coating. The difference in refractive index between the PoF inner core 302 and the PoF cladding 304 may allow the PoF cable 300 to act as a waveguide for light to travel the length of the PoF cable 300 with low loss. The difference in refractive index between the PoF inner core 302 and the PoF cladding 304 may be achieved by adjusting the composition of the PoF inner core 302 and or the composition of the PoF cladding 304. The PoF inner core diameter d6 may be selected to carry optical power while satisfying bend radius and thermal constraints of the cable. In certain embodiments, d6 is between 5 micrometers and 3 millimeters. In certain embodiments, d6 is between 25 micrometers and 1 millimeter. In certain embodiments, d6 is between 50 micrometers and 600 micrometers. In certain embodiments, d6 is between 100 micrometers and 500 micrometers. Larger core diameters may be selected to increase optical power handling capability, while smaller diameters may be selected to improve bend tolerance and packing density. The PoF cladding outer diameter d7 may be selected to provide optical confinement and mechanical protection. In certain embodiments, d7 is between 10 micrometers and 3 millimeters. In certain embodiments, d7 is between 50 micrometers and 2 millimeters. In certain embodiments, d7 is between 125 micrometers and 1 millimeter. In certain embodiments, d7 is between 200 micrometers and 800 micrometers. The cladding thickness may be selected in coordination with refractiveindex contrast to provide guided optical transmission while maintaining structural robustness. The refractive index contrast between the PoF inner core 302 and the PoF cladding 304 determines the numerical aperture (NA) of the PoF cable and controls optical confinement and power delivery. The refractive index difference between the PoF inner core 302 and the PoF cladding 304 may be expressed as Delta PoF N, where Delta PoF N equals PoF N core minus PoF N cladding. The refractive index of the PoF inner core 302 (PoF N core) may be between 1.35 and 2.10. In certain embodiments, PoF N core may be between 1.44 and 1.55. In certain embodiments, PoF N core may be between 1.55 and 1.90. The refractive index of the PoF cladding 304 (PoF N cladding) may be between 1.30 and 1.90. In certain embodiments, PoF N cladding may be between 1.35 and 1.50. In certain embodiments, PoF N cladding may be between 1.40 and 1.48. Delta PoF N may be between 0.0005 and 0.40. In certain embodiments, Delta PoF N may be between 0.002 and 0.05. In certain embodiments, Delta PoF N may be between 0.01 and 0.20. In certain embodiments, Delta PoF N may be between 0.05 and 0.40. In certain embodiments, Delta PoF N is positive such that PoF N core exceeds PoF N cladding to provide guided optical transmission along the length of the PoF cable. In certain embodiments, the PoF cable has a numerical aperture between 0.05 and 0.80, and in certain embodiments between 0.10 and 0.60, selected to balance optical confinement, bend tolerance, and high-power transmission capability. The PoF inner core 302 and PoF cladding 304 may comprise silica glass, doped silica glass, fluorophosphate glass, tellurite glass, germanate glass, polymer optical fiber materials, or combinations thereof.

[0045] FIG. 4A OELR Assembly

[0046] FIG. 4A depicts an opto electrolysis light rod (OELR) assembly 500. An OELR assembly 500 may include a PoF cable 501 coupled to an OELR 502 via a coupler 503. OELR 502 may include an end cap 504. PoF cable 501 may have a cross section as described for PoF cable 300, and OELR 502 may have a cross section as described for OELR 100. OELR 502 may have a length 11 between 1 foot and 128 feet. In certain embodiments, 11 may be between 1 foot and 32 feet. In certain embodiments, 11 may be between 2 feet and 16 feet. In certain embodiments, 11 may be between 4 feet and 8 feet. Each OELR assembly may deliver opticalpower WOELR. In certain embodiments, WOELR may be between 0.1 watt and 500 watts. In certain embodiments, WOELR may be between 1 watt and 100 watts. In certain embodiments, WOELR may be between 5 watts and 50 watts. Hydrogen production rate per OELR assembly may be expressed as Hw, representing grams of hydrogen produced per hour. In certain embodiments, Hw may be between 0.001 grams per hour and 0.05 grams per hour per watt of delivered optical power, depending on optical efficiency, spectral matching, catalyst loading, and quantum efficiency. In certain embodiments, hydrogen production efficiency may approach theoretical thermodynamic limits for water splitting under the selected optical and catalytic conditions.

[0047] FIG. 4B Reactor Element Assembly

[0048] FIG. 4B depicts a reactor element assembly 600. A reactor element assembly 600 may include a plurality nl of OELR assemblies 500, 607 arranged generally parallel to one another. In certain embodiments, nl may be between 2 and 800. In certain embodiments, nl may be between 10 and 400. In certain embodiments, nl may be between 50 and 200. The OELR assemblies 500, 607 may be arranged in a square array, hexagonal array, cylindrical array, triangular array, or other polygonal array. FIG. 4B illustrates an example reactor element assembly 600 comprising 100 OELR assemblies arranged in a 10 by 10 square array. Reactor element assembly 600 may include structural support components comprising one or more grid plate support brackets 601, 608, 609, 610, 611 and one or more grid plates 602 configured to support and maintain alignment of OELR assemblies 500. In certain embodiments, the reactor element assembly includes one or more intermediate grid plate support brackets, where the number of intermediate support brackets n2 may be between 1 and 20. The grid plates and support brackets may include cells 604 arranged in an array corresponding to the spatial arrangement of the OELR assemblies. The reactor element assembly 600 may have dimensions including height 14, width 17, and depth 16. In certain embodiments, height 14 may be between 1 foot and 128 feet. In certain embodiments, height 14 may be between 2 feet and 32 feet. In certain embodiments, height 14 may be between 4 feet and 16 feet. The height 14 may be coordinated with OELR length 11 such that the OELR assemblies are positioned to optimize optical utilization and hydrogen generation within thereactor volume. In certain embodiments, width 17 may be between 1 foot and 32 feet. In certain embodiments, width 17 may be between 2 feet and 16 feet. In certain embodiments, depth 16 may be between 1 foot and 32 feet. In certain embodiments, depth 16 may be between 2 feet and 16 feet.

[0049] FIG. 4C Cell

[0050] FIG. 4C depicts a top view of a cell 700. A cell 700 may include a frame system 706 configured to receive and stabilize an OELR assembly 500 such that the OELR assembly extends along height 14 of reactor element assembly 600. The frame system 706 may include a central opening having diameter dlO selected to permit insertion and support of OELR assembly 500. In certain embodiments, dlO may be between 50 micrometers and 50 millimeters. In certain embodiments, dlO may be between 100 micrometers and 10 millimeters. In certain embodiments, dlO may be between 200 micrometers and 5 millimeters. The diameter dlO may be selected relative to the outer diameter d5 of the OELR such that the OELR is mechanically supported while permitting thermal expansion and fluid flow around the assembly. Cell 700 may have a cell width 18 representing spacing between adjacent OELR assemblies. The cell width 18 may be selected to permit movement of water and evolved gases while maintaining reactor packing density. In certain embodiments, 18 may be between 100 micrometers and 100 millimeters. In certain embodiments, 18 may be between 500 micrometers and 20 millimeters. In certain embodiments, 18 may be between 1 millimeter and 10 millimeters. The spacing may be coordinated with porous layer thickness, hydrogen evolution rate, and desired fluid flow characteristics within the reactor.

[0051] FIG. 4D Grid Plate

[0052] FIG. 4D depicts a top view of a grid plate 800. Reactor element assemblies 600 may be comprised of a number of grid plates 802. A grid plate 802 may be integrated with a grid plate support bracket 601, 609, 608, 610, and or 611 and or end cap grid plate 602 and or base grid plate support bracket 611. Each grid plate 802 may be comprised of cells 801. Each cell 801 may provide physical support to an OELR assembly 500.FIG. 5 A Reactor Element Assembly View

[0053] FIG. 5A depicts a zoomed out view of a reactor element assembly 900, 911.

[0054] FIG. 5B Reactor Core

[0055] FIG. 5B depicts a reactor core 1000. Reactor core 1000 may comprise a plurality n3 of reactor element assemblies 600 arranged within a structural enclosure and retained between an upper plate 1004 and a lower plate 1009. In certain embodiments, n3 may be between 1 and 100,000. In certain embodiments, n3 may be between 10 and 10,000. In certain embodiments, n3 may be between 100 and 1,000. The number n3 may be selected based on desired hydrogen production capacity, optical power availability, fluid flow design, and plant footprint constraints. The distance 19 between upper plate 1004 and lower plate 1009 may define the active height of reactor core 1000. In certain embodiments, 19 may be between 1 foot and 128 feet. In certain embodiments, 19 may be between 2 feet and 32 feet. In certain embodiments, 19 may be between 4 feet and 16 feet. The height 19 may be coordinated with reactor element assembly height 14 such that the reactor element assemblies are supported and aligned to optimize hydrogen generation and fluid transport within the reactor volume. The upper plate 1004 and the lower plate 1009 may be integrated into the reactor such that the upper plate 1004 and the lower plate 1009 provide structural stability to support the reactor element assemblies 1008, 900, 911, 600. The upper plate 1004 and the lower plate 1009 may be comprised of housings 1002 that provide structural support for reactor element assemblies 1008, 900, 911, 600. The housings 1002 may be arranged in an array. The number of housings 1002 in the upper plate 1004 and or the lower plate 1009 may be approximately equal to the number of reactor element assemblies 1008, 900, 911, 600. The number of housings 1002 in the upper plate 1004 and or the lower plate 1009 may be more than the number of reactor element assemblies 1008, 900, 911, 600. Some housings 1002 may be left empty. Some housings 1002 may contain sensors. Some housings 1002 may contain components that improve hydrogen production. Some housings 1002 may contain further structural support. Some housings 1002 may contain temperature control components. The reactor core may contain reactor element assemblies that may contain OELR assemblies 500 that may contain PoF cables 501 and or OELRs 502. The OELRs 502 may be within thereactor. The PoF cables 501 may transport light from the light source to the OELRs 502. The PoF cables 501 may be substantially outside of the reactor while the OELRs 502 may be substantially inside the reactor. The reactor may allow reactor element assemblies 1008, 900, 911, 600 to extend outside of the reactor 1003 through a port. The reactor may allow OELR assemblies 500 to extend outside of the reactor through a port 1110. The reactor 1003 may be comprised of a port 1110 containing PoF cables 501 that extend outside of the reactor.

[0056] FIG. 6A Reactor

[0057] FIG. 6A depicts a reactor 1100. Reactor 1100 may include a reactor core 1000 positioned within a reactor enclosure system 1117 and may further include reactor outer wall 1113, reactor inner wall 1109, reactor lid 1102, water mixture feed port 1118, water mixture recycle inlet port 1114, water mixture recycle outlet port 1107, temperature control fluid inlet 1101, temperature control fluid outlet 1115, temperature control fluid jacket ft 12, hydrogen mixture outlet port 1116, water mixture condensation system 1104, hydrogen mixture enrichment system 1103, OELR assembly conduit 1111, and one or more OELR assembly ports 1110. The number of OELR assemblies entering reactor 1100 through a single port may be represented by Nport. In certain embodiments, Nport may be between 1 and 100,000. In certain embodiments, Nport may be between 10 and 10,000. In certain embodiments, Nport may be between 100 and 1,000. In certain embodiments, a plurality of OELR assembly ports may be provided, and the total number of OELR assemblies within reactor 1100 may be scaled by increasing the number of ports. The number of OELR assemblies per port may be selected based on OELR outer diameter, packing density, thermal management constraints, and mechanical sealing requirements.

[0058] FIG. 6B Opto Electrolysis Hydrogen Plant

[0059] FIG. 6B depicts a solar-driven opto electrolysis hydrogen plant 1200. Opto electrolysis hydrogen plant 1200 may comprise a reactor 1202, a hydrogen isolation, purification, and / or storage train 1201, 1204, 1205, 1206, a hydrogen tank outlet port 1207, a temperature control fluid loop 1211, a temperature control fluid loop pump 1212, a temperature control fluid control system 1213, a water mixture recycle loop 1208, a water mixture recycle loop pump 1209, a water mixture recycle loop control system 1210, a water mixture inlet line 1215, awater mixture tank and / or pump system 1216, an OELR aggregation system 1217, one or more PoF cables 1214, and a solar radiation collection system optically coupled to a light source 1218. In certain embodiments, light source 1218 comprises concentrated or unconcentrated sunlight collected by one or more solar radiation collection assemblies and transmitted through a power over fiber optical transmission network to one or more opto electrolysis light rods within reactor 1202. The solar radiation collection system may comprise lenses, Fresnel lenses, meta lenses, concentrators, waveguides, collimators, optical couplers, and / or aggregation networks configured to capture solar radiation and deliver optical power to the reactor. In certain embodiments, sunlight is the primary energy input driving hydrogen production. In alternative embodiments, light source 1218 may additionally or alternatively comprise a laser, LED array, mercury vapor lamp, xenon arc lamp, deuterium lamp, halogen lamp, infrared source, or combinations thereof. Such artificial light sources may supplement or replace sunlight in certain operating conditions. Opto electrolysis hydrogen plant 1200 may be configured to produce hydrogen at an output rate Poutput expressed in metric tons per hour of solar irradiation. In certain embodiments, Poutput may be between 0.0001 metric tons per hour and 0.1 metric tons per hour. In certain embodiments, Poutput may be between 0.001 metric tons per hour and 1 metric ton per hour. In certain embodiments, Poutput may be between 0.01 metric tons per hour and 10 metric tons per hour. Hydrogen production rate may scale with total collected solar surface area, optical transmission efficiency, catalyst efficiency, photon utilization efficiency, and reactor mass transport characteristics. Light delivered to the reactor may include ultraviolet wavelengths between 100 nanometers and 400 nanometers, visible wavelengths between 400 nanometers and 700 nanometers, and near infrared wavelengths between 700 nanometers and 1500 nanometers. Upconversion and / or downconversion centers located within the opto electrolysis light rod may modify the spectral distribution of incident solar radiation such that emitted light spectrally overlaps, as defined herein, with an absorption band of selected photocatalytic centers.

[0060] FIG. 7A Solar Radiation Collection Assembly (SRCA) Top ViewFIG. 7A depicts a top view of a solar radiation collection assembly (SRC A) 1300. The SRC A 1300 may be configured as a sunlight-first optical power collection system. The SRCA 1300 may be comprised of a lens 1303 configured to collect and concentrate solar radiation, a frame 1301 configured to support the lens 1303, and a seal system 1302 configured to form a seal between the lens 1303 and the frame 1301. The lens 1303 may be a convex lens, planoconvex lens, biconvex lens, Fresnel lens, aspheric lens, achromatic lens, patterned lens, meta-lens, non-imaging concentrator lens, or combinations thereof. The lens 1303 may be fabricated from glass, polymer, silica, acrylic, polycarbonate, or other optically transmissive materials. In certain embodiments, optical coatings including anti-reflection coatings, UV-stable coatings, and / or protective coatings may be applied to reduce reflection and environmental degradation. The lens 1303 may have a lens diameter dll between 1 inch and 100 inches. In certain embodiments, lens diameter dll may be between 3 inches and 7 inches. In certain embodiments, lens diameter dll may be between 4 inches and 6 inches. Selection of lens diameter dll may be based on optical coupling efficiency, manufacturability, structural considerations, and etendue matching between the sun and an optical transmission network. The lens 1303 may be designed such that optical losses are less than 10 percent, less than 5 percent, less than 1 percent, less than 0.5 percent, less than 0.1 percent, less than 0.05 percent, or less than 0.01 percent of incident light entering the lens 1303. In certain embodiments, trade-offs may be made between lens diameter dll, focal length, focal plane depth, numerical aperture, focal spot diameter, materials of construction, coatings, shape, and manufacturing technique.

[0061] The lens frame system 1301 may have a diameter dl2 that is between 0.1 percent and 20 percent greater than dll. The lens frame system 1301 may have a hexagonal shape, square shape, circular shape, or polygonal shape with n4 sides, where n4 may be between 3 and 100. In certain embodiments, concentrated solar radiation collected by lens 1303 may be coupled into an optical transmission network using one or more coupling architectures, including combinations thereof

[0062] (A) Direct fiber coupling, wherein light is focused substantially directly into an entrance face of a power-over-fiber (PoF) inner core 302. (B) Intermediate waveguide coupling, whereinlight is coupled from lens 1303 into an intermediate waveguide and subsequently into PoF inner core 302. (C) Secondary concentrator coupling, wherein light is coupled from lens 1303 into a secondary concentrator configured to reshape angular distribution and / or spot size prior to coupling into PoF inner core 302. In certain embodiments, one or more optical parameters are selected to promote efficient coupling of sunlight subject to optical etendue constraints. Lens diameter, focal length, and / or numerical aperture may be selected based on an etendue match between the angular extent of the sun and an acceptance cone of the optical transmission network such that a substantial portion of collected sunlight may be coupled into the PoF inner core without exceeding acceptance etendue. In certain embodiments, solar radiation provides a primary optical power input to the system. One or more auxiliary light sources may optionally supplement solar input during low irradiance conditions, startup, and / or spectral control.

[0063] FIG. 7B SRCA Rear View

[0064] FIG. 7B depicts a back view of a SRCA 1400. The SRCA 1400 may have a back side frame system 1401 that may provide structural support and may provide a seal and or enclosure. The SRCA 1400 may have a coupler 1403 that may connect a power over fiber (PoF) cable 1402 to the back side frame system 1401.

[0065] FIG. 8A Solar Radiation Collection Assembly (SRCA) Side View

[0066] FIG. 8A depicts a side view of a solar radiation collection assembly (SRCA) 1500. The SRCA 1500 may be configured as a sunlight-first optical collection module. The SRCA 1500 may be comprised of a lens 1501 configured to collect and concentrate solar radiation, a frame 1503 configured to hold the lens 1501 in position, and a lens frame seal system 1502 configured to form a seal between the lens 1501 and the frame 1503. The lens 1501 may be a convex lens, plano-convex lens, biconvex lens, Fresnel lens, aspheric lens, achromatic lens, non-imaging concentrator lens, or combinations thereof. The lens 1501 may be fabricated from glass, silica, acrylic, polycarbonate, or other optically transmissive materials. In certain embodiments, the lens 1501 may include anti-reflection coatings, UV-stable coatings, and / or protective coatings to reduce optical loss and environmental degradation. The frame 1503 may provide structural stability and environmental protection for the lens 1501. The frame1503 may include a first side wall 1504 extending around at least a portion of the perimeter of the SRCA 1500 to provide enclosure and mechanical support. The frame 1503 may further include a second side wall 1505 configured to define a housing depth and to support optical alignment between the lens 1501 and an optical coupling interface. The second side wall 1505 may have a length 112 between 0.1 inch and 2 feet. In certain embodiments, 112 may be between 0.1 inch and 1 inch, between 1 inch and 3 inches, between 3 inches and 7 inches, between 7 inches and 12 inches, or between 1 foot and 2 feet. Selection of 112 may be based on focal length of the lens 1501, desired focal plane position, environmental sealing requirements, and structural considerations. In certain embodiments, the lens 1501 may be positioned within the frame 1503 such that concentrated solar radiation is directed toward a focal region aligned with an optical transmission network, including a power-over-fiber (PoF) inner core. The distance between the lens 1501 and the optical coupling interface may be selected to optimize optical coupling efficiency subject to etendue constraints and acceptance angle of the optical transmission network. The lens frame seal system 1502 may comprise an elastomeric gasket, adhesive sealant, compression seal, or other sealing structure configured to reduce ingress of moisture, dust, and contaminants while maintaining optical alignment. In certain embodiments, the SRCA 1500 may be mounted in a fixed orientation or coupled to a solar tracking system configured to maintain alignment with the sun to improve optical coupling efficiency throughout the day.

[0067] FIG. 8B SRCA Exploded View

[0068] FIG. 8B depicts an exploded view of a SRCA 1600. A SRCA 1600 may contain stabilization posts 1607 that may provide structural stability to a frame system 1604, a first side wall 1606, and a second side wall 1612. The SRCA 1600 may be comprised of a lens 1601 that may collect and concentrate light, a frame 1604 to hold the lens 1601 in position, and a lens frame seal system 1602 to form a seal between the lens 1601 and the frame 1604. The SRCA 1600 may contain a spacer 1605 to accommodate the lens 1601 thickness. The SRCA 1600 may contain a waveguide 1613 that may accept the light and may guide it into an optional collimator 1614. The waveguide 1613 may be designed to further concentrate light from the lens 1601. Light exiting the waveguide 1613 may enter the optional collimator 1614 and or a waveguide to PoF coupler 1617 that may be connected to a PoF cable 1616. The positioningof the waveguide 1613, the optional collimator 1614, the waveguide to PoF coupler 1617, and the PoF cable 1616 may reduce light loss through the system. A SRCA 1600 may be comprised of a waveguide framework 1615 that may provide structural support to the waveguide 1613, the optional collimator 1614, the waveguide to PoF coupler 1617, and or the PoF cable 1616. The waveguide framework 1615 may act as a cage and may secure the waveguide 1613, the optional collimator 1614, the waveguide to PoF coupler 1617, the PoF cable 1616, and or the assembly to the second side wall 1612. The SRCA 1600 may contain a seal 1610 to protect a waveguide opening 1609 from contamination.

[0069] FIG. 9A Panel Sub Assembly Top View

[0070] FIG. 9A depicts a top view of a panel sub assembly 1700. The panel sub assembly 1700 may be comprised of a number n5 of solar radiation collection assemblies (SRCAs) 1300 arranged in a grouped configuration. The number n5 may be between 1 and 1,000. In certain embodiments, n5 may be between 1 and 5, between 5 and 10, between 10 and 100, or between 100 and 1,000. FIG. 9A depicts an example where n5 equals 7. The SRCAs 1300 within the panel sub assembly 1700 may be arranged in a linear array, square array, hexagonal array, triangular array, circular array, or other polygonal arrangement. The SRCAs 1300 may be joined together and structurally supported by a panel sub assembly frame 1701. The panel sub assembly frame 1701 may provide mechanical stability, alignment control, environmental protection, and structural integration for multiple SRCAs 1300. In certain embodiments, spacing between adjacent SRCAs 1300 may be selected to reduce optical shading, thermal coupling, and structural interference while maximizing solar collection density.

[0071] FIG. 9B Panel Sub Assembly Bottom View

[0072] FIG. 9B depicts a bottom view of a panel sub assembly 1800. The panel sub assembly 1800 may be comprised of a number n6 of SRCAs 1300 corresponding to the top view configuration. The number n6 may be between 1 and 1,000. In certain embodiments, n6 may be between 1 and 5, between 5 and 10, between 10 and 100, or between 100 and 1,000. FIG.

[0073] 9B depicts an example where n6 equals 7. Each SRCA 1300 within the panel sub assembly1800 may be optically coupled to a power-over-fiber (PoF) coupler 1802. The PoF coupler 1802 may be configured to receive concentrated solar radiation from the SRCA 1300 and couple the optical power into a PoF inner core. A PoF cable 1803 may transport concentrated light as optical power from the panel sub assembly 1800 to an optical aggregation system or directly to one or more opto-electrolysis light rods. In certain embodiments, optical power from multiple SRC As 1300 may be combined, multiplexed, or aggregated into one or more PoF cables 1803. In certain embodiments, each SRCA 1300 may be coupled to a dedicated PoF cable 1803. In certain embodiments, intermediate optical combining elements may be used prior to transmission. The panel sub assembly 1800 may be configured as a modular sunlight collection unit capable of being combined with additional panel sub assemblies to scale total optical power delivered to a reactor system.

[0074] FIG. 10A Optical Power Transmission Network

[0075] FIG. 10A depicts an optical power transmission network 1900. The optical power transmission network 1900 may be configured to aggregate and transport concentrated solar radiation collected from a plurality of solar radiation collection assemblies (SRCAs). The network 1900 may be comprised of one or more input couplers 1902, one or more intermediate couplers 1912, and multiple power-over-fiber (PoF) cables 1903, 1904, 1905, 1906, 1907, 1908, 1909. In certain embodiments, multiple PoF cables 1903-1909 may be optically coupled to a single higher-capacity PoF cable 1913. An aggregation waveguide assembly 1901 may be configured to combine optical power from a plurality of PoF cables. The aggregation waveguide assembly 1901 may comprise: a plurality of input couplers 1902 configured to receive light from respective PoF cables 1903-1909; a combining waveguide 1910 configured to spatially and / or angularly combine optical power from the plurality of PoF cables; a merged waveguide section 1911 configured to form a combined optical column; and an aggregation waveguide-to-fiber coupler 1912 configured to couple the aggregated optical power into a single high-capacity PoF cable 1913. The combining waveguide 1910 may utilize geometric overlap, non-imaging optics, fused fiber bundles, taper structures, multi-core aggregation, coherent or incoherent optical combining, or other optical aggregation techniques. In certain embodiments, individual PoF cables 1903-1909may each transport optical power between 0.1 watt and 1 kilowatt. In certain embodiments, individual PoF cables may transport between 0.1 watt and 10 watts, between 10 watts and 100 watts, or between 100 watts and 1 kilowatt. In certain embodiments, the aggregated PoF cable 1913 may transport between 1 watt and 500 kilowatts. In certain embodiments, the aggregated PoF cable 1913 may transport between 1 watt and 10 kilowatts, between 10 kilowatts and 50 kilowatts, between 50 kilowatts and 100 kilowatts, or between 100 kilowatts and 500 kilowatts. Selection of cable core diameter, refractive index contrast, numerical aperture, and thermal management architecture may be coordinated to support the selected optical power level while avoiding excessive nonlinear effects, material degradation, or thermal damage. In certain embodiments, the optical power transmission network 1900 may be configured to preserve optical etendue during aggregation such that the acceptance cone of the downstream optical component is not exceeded.

[0076] FIG. 10B Panel Sub Assembly With Optical Network

[0077] FIG. 10B depicts a bottom side illustration of a panel sub assembly 2000. A panel sub assembly 2000 may be connected to an optical power transmission network 2002, 1900.

[0078] FIG. 11A Panel Top View

[0079] FIG. 11A depicts a top view of a panel 2100. The panel 2100 may be comprised of a number n7 of panel sub assemblies 1700 arranged in a modular configuration. The number n7 may be between 1 and 1,000. In certain embodiments, n7 may be between 1 and 5, between 5 and 10, between 10 and 100, or between 100 and 1,000. The panel sub assemblies 1700 may be arranged within panel 2100 to provide a high optical collection surface area while minimizing optical shading, structural obstruction, and transmission loss. The panel 2100 may be configured to maximize solar exposure and optical packing density. In certain embodiments, each panel sub assembly 1700 may be comprised of a plurality of SRC As 1300 arranged in a geometric configuration. FIG. HA depicts an example in which each panel sub assembly 1700 includes seven hexagonally shaped SRCAs 1300 arranged in a clustered configuration. In this example, the panel 2100 includes seven panel sub assemblies 1700 arranged in a larger array. The panel 2100 may be configured in linear, rectangular, hexagonal, circular, or other polygonal layouts depending on installation constraints andsolar tracking architecture. In certain embodiments, adjacent panel sub assemblies 1700 may share structural members or alignment features to maintain optical coupling precision. The panel 2100 may be configured as a modular sunlight collection unit capable of being combined with additional panels to scale total optical power delivered to an optical aggregation network and ultimately to a reactor system.

[0080] FIG. 11B Panel Bottom View

[0081] FIG. 11B depicts a bottom view of a panel 2200. The panel 2201 may have sub assemblies 2000 that may each have a single high capacity PoF cable 2202 exiting the sub assembly 2000.

[0082] FIG. 12 Panel System

[0083] FIG. 12 illustrates a panel system 2300. The panel system 2300 may have a panel 2100 that may be mounted on a panel rack 2302 that provides stability for the panel 2100. The panel rack 2302 may provide a mechanism for the panel 2100 to track the sun and may use a variety of machine learning, artificial intelligence, software, and other computer aided tracking methods and hardware to track the sun. The panel rack 2302 may be self powered. The panel rack 2302 may be self powered by converting optical power from one or more SRCAs 1300 to electrical power on and or near the panel system 2300. The panel rack 2302 may also have a battery to store excess electrical power. A self powered panel rack with battery storage may be referred to as a self powered battery operated panel rack. The panel system 2300 may have a number n8 of high capacity PoF cables 2303 that may exit the panel rack 2302 where n8 may be between 1 and 5, 5 and 6, 7 and 7, 6 and 8, 8 and 10, 10 and 100, and or 100 and 1,000. A bundle of high capacity PoF cables 2303 may exit the panel rack 2302 as a bundle of high capacity PoF cables 2303.

[0084] SPECTRAL CONVERSION ARCHITECTURE AND PHO TO CATALYTIC FUNCTIONAL RELATIONSHIP

[0085] In certain embodiments, the opto-electrolysis light rod 100 is configured as an integrated optical catalytic system in which spectral conversion functionality is physically and functionally separated from photocatalytic functionality. The inner core 101 may compriseupconversion additives, downconversion additives, light scattering centers, and combinations thereof. The inner core 101 may function primarily as an optical waveguide and spectral conditioning medium. The upconversion additives in the inner core 101 may absorb one or more photons at a first wavelength and emit photons at a shorter wavelength. The downconversion additives in the inner core 101 may absorb one or more photons at a first wavelength and emit photons at a longer wavelength. The spectral conversion additives may be selected such that emitted photons correspond to a wavelength range that enhances absorption, quantum efficiency, stability, and / or hydrogen evolution activity of the photocatalytic centers 109, 110. The light scattering centers located within the inner core 101 and / or at the core cladding interface may redistribute guided optical energy radially outward toward cladding 102 and porous layer 107. The porous layer 107 may comprise photocatalytic centers 109, 110 configured to convert water into hydrogen in the presence of light. In certain embodiments, the photocatalytic centers are located primarily within porous layer 107 and are physically separated from the spectral conversion additives located within inner core 101. In operation, optical energy may enter the inner core 101, propagate longitudinally along the opto-electrolysis light rod 100, undergo wavelength modification via upconversion and / or downconversion processes, and be spatially redistributed by light scattering centers toward porous layer 107. Photons having wavelengths matched to the absorption spectrum of the photocatalytic centers 109, 110 may be absorbed within porous layer 107, thereby driving hydrogen evolution from water contacting porous layer 107.

[0086] SPECTRAL MATCHING AND SYSTEM OPTIMIZATION

[0087] In certain embodiments, the opto-electrolysis light rod 100 is designed as a spectrally optimized catalytic waveguide in which the spectral properties of inner core 101 are selected based on the absorption characteristics of photocatalytic centers 109, 110.

[0088] The design of inner core 101 may take into account:

[0089] • the spectral distribution of the incident light source;

[0090] • the absorption spectrum of the photocatalytic centers;

[0091] • the emission spectrum of the upconversion and / or downconversion additives;• photon propagation characteristics within the core and cladding;

[0092] • radial scattering efficiency toward porous layer 107;

[0093] • and catalytic reaction efficiency within porous layer 107.

[0094] In certain embodiments, wavelengths that would otherwise pass through the system without contributing to hydrogen generation are converted by the spectral conversion additives into wavelengths corresponding to an absorption band of the photocatalytic centers 109, 110.

[0095] The opto-electrolysis light rod 100 may therefore be configured such that:

[0096] (1) inner core 101 performs spectral conditioning and wavelength conversion;

[0097] (2) light scattering centers distribute conditioned light radially; and

[0098] (3) photocatalytic centers within porous layer 107 convert the spectrally matched light into hydrogen from water.

[0099] In certain embodiments, the spectral conversion additives are selected such that the emitted wavelength range overlaps at least partially with a peak absorption region of the photocatalytic centers.

[0100] SPECIFIC EXEMPLARY DOWNCONVERSION GLASS MATCHED TO PHOTOCATALYTIC CENTERS

[0101] In certain embodiments, inner core 101 comprises a downconversion glass composition engineered to convert ultraviolet and / or non-optimal wavelengths into wavelengths corresponding to an absorption band of a selected photocatalytic center. Inner core 101 may comprise silicate glass, borosilicate glass, aluminosilicate glass, phosphate glass, fluorophosphate glass, tellurite glass, germanate glass, or combinations thereof, doped with one or more rare earth ions configured to provide downconversion emission. In one embodiment, inner core 101 may comprise tellurite glass or fluorophosphate glass doped with Eu3+ions. Eus+doped glass may absorb ultraviolet light approximately between 250 nm and 400 nm and emit photons approximately between 600 nm and 620 nm. In certain embodiments, porous layer 107 may comprise copper(I) oxide, CU2O, as a photocatalytic center. Cu2O exhibits absorption within the visible spectrum including wavelengths near 600nm. Ultraviolet light entering inner core 101 may therefore be absorbed by Eu3+dopants and re-emitted in a spectral region corresponding to an absorption band of Cu2O photocatalytic centers located in porous layer 107. In another embodiment, inner core 101 may comprise Yb3+ / Er3+co-doped glass configured to absorb near infrared light approximately between 900 nm and 1000 nm and emit visible light approximately between 520 nm and 660 nm. Porous layer 107 may comprise TiO2photocatalytic centers configured to absorb ultraviolet and visible wavelengths. Near infrared light may therefore be converted into visible wavelengths that contribute to catalytic activity. In another embodiment, inner core 101 may comprise Nd3+doped glass configured to absorb near infrared light around 800 nm and emit photons approximately between 400 nm and 600 nm. Porous layer 107 may comprise ZnO, CdS, BiVO4, or combinations thereof. The emitted wavelengths may correspond to absorption regions of such photocatalytic centers. The selection of downconversion dopant, host glass composition, dopant concentration, and emission spectrum may be determined based on the spectral characteristics of the light source, the absorption characteristics of the photocatalytic centers, and reactor operating conditions. In certain embodiments, the downconversion glass and the photocatalytic centers are selected as a matched pair such that the emission spectrum of inner core 101 overlaps at least partially with a peak absorption region of the photocatalytic centers located within porous layer 107. The opto-electrolysis light rod 100 may therefore be engineered as a spectrally matched catalytic waveguide in which spectral conversion within the core enhances hydrogen generation efficiency within the porous photocatalytic layer.

[0102] HYDROGEN ISOLATION PURIFICATION STORAGE TRAIN

[0103] A hydrogen isolation, purification, and / or storage train may be comprised of hydrogen purification processes and / or equipment. A hydrogen purification process and / or equipment may include pressure swing adsorption (PSA), cryogenic distillation, temperature swing adsorption, vacuum swing adsorption, membrane separation, and / or catalytic combustion. A hydrogen isolation, purification, and / or storage train may be comprised of separation membranes. A separation membrane may be a proton exchange membrane (PEM), Nafion®, palladium-based membranes, palladium alloy-based membranes, microporous inorganicmembranes, ceramic membranes, zeolite membranes, metal-organic framework membranes, and / or hollow fiber membranes. A hydrogen isolation, purification, and / or storage train may further be comprised of compression systems, compressor units, storage vessels, sensors, valves, and / or safety equipment.

[0104] EXEMPLARY EMBODIMENT 1 : UV DOWNCONVERSION CORE MATCHED TO Cu2O PHOTOCATALYTIC CENTERS

[0105] In one exemplary embodiment, an opto-electrolysis light rod (OELR) comprises an inner core formed from a tellurite glass host doped with Eu3+as a downconversion additive. The inner core is configured to absorb ultraviolet wavelengths and emit visible wavelengths in a band overlapping an absorption region of Cu2O photocatalytic centers disposed within a porous layer. In this embodiment, the inner core comprises tellurite glass doped with Eu3+at a concentration between 0.1 mol percent and 2.0 mol percent. The inner core has a diameter d2between 250 pm and 1 mm. The cladding comprises a fluorophosphate glass having a refractive index lower than the inner core to provide a waveguiding numerical aperture configured for power-over-fiber optical delivery. The cladding diameter d4is between 600 pm and 2 mm. An (core minus cladding) is between 0.01 and 0.06. Light scattering centers are incorporated at the core-cladding interface and / or within the inner core. In one example, the scattering centers comprise silica or alumina nanoparticles with an average diameter between 50 nm and 500 nm at a loading between 0.01 wt percent and 1.0 wt percent, distributed along the rod length to promote radial outcoupling of guided light. The porous layer comprises a porous glass or ceramic scaffold having a thickness ti between 50 pm and 500 pm and a porosity between 0.4 and 0.85. The porous layer includes Cu2O photocatalytic centers. In one example, Cu2O is incorporated as nanoparticles having an average diameter between 10 nm and 200 nm at a loading between 0.5 wt percent and 15 wt percent within the porous scaffold. In another example, Cu2O is coated onto pore surfaces via a solution deposition process such that Cu2O coats at least a portion of internal pore surfaces. The pore size distribution comprises pores with an average pore diameter between 50 nm and 10 pm to permit water diffusion and gas transport. In operation, a solar radiation collection assembly delivers concentrated light into a PoF cable optically coupled to the OELR. The OELR ispositioned in a reactor such that the porous layer is in contact with water. Ultraviolet components of the delivered light are absorbed by Eu3+dopants in the inner core and reemitted in the visible band, and the radial scattering centers direct a portion of the guided and downconverted light into the porous layer. The emitted visible photons are absorbed by Cu2O photocatalytic centers to drive hydrogen evolution from water at the porous layer.

[0106] EXEMPLARY EMBODIMENT 2: NIR UPCONVERSION CORE MATCHED TO TiO2WITH COCATALYST

[0107] In one exemplary embodiment, the OELR inner core comprises a silica-based or fluorophosphate-based glass doped with Yb3+and Er3+as upconversion additives configured to absorb near-infrared light and emit photons in visible bands that can contribute to photocatalytic activity in a porous layer containing TiO2photocatalytic centers and a cocatalyst. In this embodiment, the inner core comprises fluorophosphate glass doped with Yb3+between 0.5 mol percent and 10 mol percent and Er3+between 0.05 mol percent and 2 mol percent. The inner core diameter d2is between 100 pm and 600 pm. The cladding comprises a lower-index fluorophosphate or silica cladding with cladding diameter d4between 250 pm and 1.5 mm. An (core minus cladding) is between 0.005 and 0.03. Light scattering centers are incorporated within the inner core and / or cladding to increase radial outcoupling. In one example, scattering centers comprise voids or microbubbles formed during glass processing, where the scattering feature size is between 0.5 pm and 20 pm and the axial density of scattering features increases along the rod length to support more uniform optical depletion. The porous layer comprises TiO2photocatalytic centers. In one example, the porous layer scaffold comprises porous TiO2formed by sol-gel and sintering, with porosity between 0.5 and 0.9 and average pore size between 20 nm and 2 pm. In another example, the porous layer is a porous glass or porous ceramic scaffold coated with TiO2via atomic layer deposition or sol-gel infiltration. A cocatalyst is included, such as Pt, Ni, Co, MOS2, or Ni2P, in nanoparticle form with average size between 2 nm and 50 nm and loading between 0.01 wt percent and 2 wt percent on pore surfaces. In operation, the OELR is optically powered via a PoF network coupled to solar concentrators and / or auxiliary light sources. Near-infrared light delivered into the inner core is absorbed by Yb3+and transferredto Er3+to produce upconverted emission in visible bands. Scattering centers direct a portion of the guided and upconverted light radially into the porous layer. The TiO2photocatalytic centers, optionally assisted by the cocatalyst, utilize the absorbed photons to drive hydrogen evolution and / or overall water splitting depending on reactor configuration and optional oxygen evolution components.

[0108] EXEMPLARY EMBODIMENT 3: NIR / VISIBLE SPECTRAL CONDITIONING MATCHED TO BiVO4OR ZnO USING Nd3+

[0109] In one exemplary embodiment, the OELR inner core comprises Nd3+doped glass configured to absorb near-infrared light and emit photons within a visible band selected to overlap absorption of photocatalytic centers comprising BiVO4and / or ZnO disposed within a porous layer. In this embodiment, the inner core comprises phosphate glass doped with Nd3 +between 0.1 mol percent and 5 mol percent. The core diameter d2is between 150 pm and 1 mm. The cladding comprises a borosilicate or fluorophosphate glass having a lower refractive index than the core, with cladding diameter d4between 400 pm and 3 mm. An (core minus cladding) is between 0.005 and 0.05. The porous layer comprises a porous scaffold having thickness ti between 100 pm and 2 mm and porosity between 0.3 and 0.85. The porous layer contains photocatalytic centers comprising BiVO4particles (average diameter between 20 nm and 500 nm) and / or ZnO particles (average diameter between 10 nm and 300 nm). The photocatalytic centers are incorporated into the porous scaffold at a combined loading between 1 wt percent and 25 wt percent. In one example, the porous layer further includes a protective stability coating (e.g., thin oxide or polymer coating) applied conformally at thickness between 5 nm and 200 nm to mitigate photocorrosion while maintaining diffusion pathways. Light scattering centers are incorporated at the cladding-porous layer interface and comprise high-index nanoparticles (e.g., ZrO2or TiO2nanoparticles) with average size between 50 nm and 1 pm at loading between 0.01 wt percent and 2 wt percent, configured to couple guided light into the porous layer. The scattering center distribution may be spatially varied along the rod length to reduce intensity gradients and promote uniform photon delivery to the porous photocatalytic centers. In operation, spectrally conditioned light exiting the inner core is directed radially into the porous layervia scattering centers. The emission band overlaps absorption of BiVO4and / or ZnO to increase utilization of delivered optical power for hydrogen evolution and / or photoelectrochemical reactions.

[0110] EXEMPLARY EMBODIMENT 4: PHOTOELECTROCHEMICAL VARIANT WITH ELECTRICAL CONTACTS AND OPTIONAL BIAS

[0111] In one exemplary embodiment, the OELR is configured as a photoelectrochemical device in which the porous layer includes photocatalytic centers and electrical contacts configured to collect photogenerated charge carriers, optionally with an applied bias. Optical activation remains the primary energy input, and the optical delivery and spectral matching architecture is maintained. In this embodiment, the inner core comprises a spectrally engineered glass waveguide containing one or more downconversion additives and / or upconversion additives as described herein. The cladding surrounds the core and is configured to provide waveguiding. Scattering centers are positioned to direct conditioned light radially outward. The porous layer comprises a semiconductor photocatalytic center configured as a photocathode material, including but not limited to Cu2O, Si, GaAs, InP, MoS2-coated semiconductor structures, or protected junctions. In one example, the porous layer includes a conductive scaffold and / or embedded conductive pathways comprising carbon, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), silver nanowires, or a metal mesh layer, configured to provide electrical connectivity. A counter-electrode is positioned within the reactor and may comprise Pt, Ni, stainless steel, or other hydrogen-compatible electrode materials. A membrane separator may be included, such as a proton exchange membrane (PEM), to separate hydrogen and oxygen products. In one example, the porous layer is configured as a photocathode and an oxygen evolution electrode is provided elsewhere in the reactor. Optical power delivered through the OELR drives photogeneration within the porous photocathode structure, and a bias between 0.1 V and 2.0 V may optionally be applied to increase hydrogen evolution rate and / or lower overpotential. In another example, no external bias is applied, and the system operates as a purely light-activated photoelectrochemical hydrogen generation device. In operation, the inner core spectrally conditions incoming light such that emitted wavelengths overlap the absorption band of the porous layersemiconductor. Scattering centers extract conditioned light radially to drive carrier generation at the porous layer. Water contacts the porous layer, hydrogen evolves at the photocathode region, and evolved gases are removed from the reactor via gas handling ports.

[0112] EXEMPLARY EMBODIMENT 5: LUMINESCENT CORE WITHOUT DISCRETE LIGHT SCATTERING CENTERS

[0113] In one exemplary embodiment, the opto-electrolysis light rod comprises an inner optical core containing spectral conversion additives and is configured such that radial photon emission occurs without engineered light scattering centers. In this embodiment, the inner core comprises a host glass selected from silicate glass, borosilicate glass, fluorophosphate glass, tellurite glass, germanate glass, or combinations thereof, doped with one or more rare earth ions configured to provide photoluminescent emission. The rare earth dopants may include Eu3+, Yb3+, Er3+, Nd3+, Tm3+, Dy3+, Hos+, or combinations thereof. Dopant concentration may be between 0.01 mol percent and 10 mol percent. The inner core has a diameter d2 between 100 pm and 2 mm. The cladding surrounds the inner core and has a refractive index selected to permit optical transmission of incident light along the length of the rod. The cladding diameter d4 may be between 250 pm and 5 mm. AOELR N (core minus cladding) may be between 0.002 and 0.05. In this embodiment, no discrete engineered light scattering centers are incorporated within the inner core or cladding. Instead, radial photon emission results from spontaneous isotropic emission of photoluminescent rare earth centers following photon absorption. Emitted photons are radiated in multiple directions. A portion of emitted photons falls within escape cones defined by refractive index contrast between the inner core and surrounding regions and exits the core into the cladding and / or porous layer. In certain embodiments, the rare earth dopants themselves contribute to optical diffusion due to local refractive index variation and microscopic compositional inhomogeneity within the glass host. The spectral conversion additives therefore serve both as wavelength modifiers and as distributed radiative emission centers within the core. The porous layer comprises photocatalytic centers configured to convert water into hydrogen in the presence of light. In one example, the porous layer comprises Cu2O, TiO2, CdS, ZnO, BiVO4, g-C3N4, or combinations thereof, incorporated within a porous scaffold having porosity between 0.4 and0.9 and pore size between 10 nm and 10 pm. In operation, incident solar radiation delivered through an optical transmission network propagates through the inner core. Spectral conversion additives absorb photons at one wavelength and emit photons at a modified wavelength selected to overlap an absorption band of the photocatalytic centers. Because photoluminescent emission is isotropic, a fraction of emitted photons exits the core without requiring engineered scattering centers. These emitted photons enter the porous layer and are absorbed by photocatalytic centers to drive hydrogen evolution. In certain embodiments, the inner core is configured with reduced refractive index contrast relative to the cladding and / or porous layer to increase photon escape probability. In certain embodiments, cladding thickness and refractive index are selected to permit partial transmission of emitted photons into the porous layer while maintaining longitudinal optical delivery of excitation light. In this embodiment, the opto-electrolysis light rod functions as a spectrally engineered luminescent waveguide in which rare earth dopants provide wavelength modification and distributed radial emission without requiring discrete scattering structures.

[0114] EXEMPLARY EMBODIMENT 6: FABRICATION OF OPTO ELECTROLYSIS LIGHT ROD USING MONOLITHIC POROUS LAYER FORMATION

[0115] In certain embodiments, opto electrolysis light rod 100 is fabricated using a conventional optical fiber preform and draw process to form inner core 101 and cladding 102, followed by formation of porous layer 107 as a monolithic structure surrounding the drawn optical fiber.

[0116] Optical Core Fabrication

[0117] A glass preform comprising inner core 101 and cladding 102 may be prepared using modified chemical vapor deposition (MCVD), outside vapor deposition (OVD), vapor axial deposition (VAD), rod-in-tube processing, or related glass fabrication techniques. Inner core 101 may comprise one or more spectral conversion additives including rare earth ions such as Eus+, Er3+, Yb3+, Nd3+, Tm3+, Ho3+, Dy3+, or combinations thereof. Dopant concentration may be between 0.001 mol percent and 10 mol percent, consistent with ranges disclosed herein. The rare earth dopants may be selected such that emitted light from inner core 101 spectrally overlaps with an absorption band of selected photocatalytic centers 109, 110 located inporous layer 107. In certain embodiments, the emission peak of inner core 101 is within 1 nanometer to 150 nanometers of a peak absorption wavelength of the photocatalytic centers, and in certain embodiments within 1 nanometer to 50 nanometers of the peak absorption wavelength. In certain embodiments, the emission spectrum of inner core 101 is selected such that a substantial portion of emitted photon intensity falls within a wavelength range where the photocatalytic centers exhibit measurable absorption. This selection satisfies the spectral matching design rule disclosed herein. Following preform fabrication, the preform is thermally drawn to produce an optical fiber having core diameter d2 and cladding diameter d4 within the ranges specified in the detailed description. The refractive index difference AOELR N (inner core 101 minus cladding 102) may be selected between 0.002 and 0.37 to control numerical aperture and escape cone angle. In certain embodiments, AOELR N is selected to increase radial photon escape into porous layer 107 in accordance with the optical coupling design rule disclosed herein.

[0118] Formation of Porous Monolithic Layer

[0119] After fiber drawing, the optical fiber may be positioned within a cylindrical mold, tubing, or chromatography-style casing. Porous layer 107 may then be formed around the optical fiber as a continuous monolithic structure. In one embodiment, porous layer 107 comprises a silica-based monolith formed via sol-gel processing of silica precursors, followed by hydrolysis, condensation, aging, and controlled drying. In another embodiment, porous layer 107 comprises a polymer-based monolith including polystyrene or crosslinked styrenic systems formed via in situ polymerization in the presence of one or more porogens. Porogens may include organic solvents, phase-separating agents, or sacrificial templating materials configured to generate interconnected pore structures. In certain embodiments, porogen identity, porogen concentration, precursor ratios, phase separation kinetics, aging time, drying rate, and thermal treatment conditions are selected to achieve porosity and pore size ranges consistent with the mass transport design rule disclosed herein.POROSITY AND PORE SIZE

[0120] Porosity refers to the fraction of the total volume of porous layer 107 that is not part of the solid scaffold relative to the total volume including scaffold and pore space. Porosity P is defined as P = Vp / Vt, where Vpis pore volume and Vtis total volume of porous layer 107. In certain embodiments, porous layer 107 has a porosity between 0.20 and 0.95, between 0.30 and 0.95, between 0.30 and 0.90, or between 0.40 and 0.85. Porosity is selected to balance mechanical integrity, internal surface area, optical interaction length, photon scattering behavior, and diffusion of water and evolved gases. In certain embodiments, porosity is selected such that diffusion of water into porous layer 107 and removal of hydrogen and / or oxygen gas occurs without excessive diffusion resistance while maintaining structural stability. Pore size PS refers to an average pore diameter within porous layer 107. In certain embodiments, pore size PS is between 2 nanometers and 200 nanometers, between 20 nanometers and 10 micrometers, between 0.1 micrometers and 10 micrometers, between 10 micrometers and 100 micrometers, or between 50 nanometers and 5 micrometers. Pore size is selected to permit diffusion of water into porous layer 107 and diffusion of hydrogen and / or oxygen out of porous layer 107 while maintaining sufficient internal surface area for photocatalytic interaction and photon absorption by photocatalytic centers 109, 110. In certain embodiments, pore size and porosity are co-selected in accordance with the porosity and mass-transport design rule disclosed herein to optimize diffusion of reactants and products while preserving optical path length, catalytic surface area, and structural integrity. Pore size and porosity may be controlled by adjusting porogen identity, porogen concentration, sol-gel precursor ratios, phase separation kinetics, aging time, drying rate, and / or thermal treatment conditions during monolithic formation of porous layer 107.

[0121] Following curing and shrinkage of the monolith around the optical fiber, the integrated corecladding-monolith structure may be removed from the mold to form opto electrolysis light rod 100.

[0122] INCORPORATION OF PHOTOCATALYTIC CENTERS

[0123] Photocatalytic centers 109, 110 may be incorporated into porous layer 107 by bulk incorporation during monolith formation, by in situ growth within pore surfaces 111, bysurface immobilization following monolith synthesis, by sol-gel infiltration, by impregnation and calcination, by chemical bath deposition, by atomic layer deposition (ALD), by chemical vapor deposition (CVD), and / or by electrostatic deposition of charged particles onto oppositely charged pore surfaces. In certain embodiments, porous layer 107 is functionalized to carry a net positive or negative surface charge, and photocatalytic particles are prepared with an opposite surface charge to promote electrostatic adhesion and distribution within pore surfaces 111. Surface functional groups may include silanol, amine, carboxyl, hydroxyl, phosphate, or other anchoring chemistries configured to enhance catalyst retention and stability under aqueous operating conditions. Photocatalytic centers may include TiO2, Cu2O, CdS, ZnO, ZnS, MoS2, SrTiOs, BiVO4, Ta3N5, WO3, g-C3N4, or combinations, heterojunctions, doped forms, defect-engineered forms, and / or nanostructured variants thereof, consistent with the specification. Cocatalysts may optionally be deposited on or integrated with the photocatalytic centers as described herein to enhance charge separation, reduce overpotential, and increase hydrogen evolution efficiency.

[0124] FUNCTIONAL RELATIONSHIP

[0125] In operation, optical energy propagates longitudinally through inner core 101, undergoes wavelength modification via spectral conversion additives, and exits radially into porous layer 107 as a function of the selected refractive index contrast and numerical aperture between inner core 101 and the surrounding layers. Photons having wavelengths within an absorption band of photocatalytic centers 109, 110 are absorbed within porous layer 107, thereby driving hydrogen evolution from water contacting porous layer 107. The coordinated selection of (i) dopant emission wavelength relative to a catalyst absorption band, (ii) refractive index contrast and numerical aperture to promote controlled radial photon delivery, and (iii) pore size and porosity to balance diffusion and optical interaction length constitutes an integrated photon management and mass transport design rule configured to increase hydrogen production efficiency relative to systems lacking coordinated spectral and optical optimization.

[0126] DESIGN RULES FOR SPECTRAL MATCHING AND PHOTON DELIVERYIn certain embodiments, the opto-electrolysis light rod is engineered according to defined spectral, optical, and mass-transport design rules that coordinate wavelength conversion, photon extraction, and photocatalytic interaction.

[0127] 1. Spectral Matching Design Rule

[0128] In certain embodiments, spectral conversion additives within the inner optical core are selected such that an emission peak wavelength of the spectral conversion additives is positioned within a defined proximity to a peak absorption wavelength of the photocatalytic centers disposed within the porous layer. In certain embodiments, the emission peak of the spectral conversion additives is within plus or minus 200 nanometers, plus or minus 100 nanometers, plus or minus 50 nanometers, plus or minus 25 nanometers, or plus or minus 10 nanometers of a peak absorption wavelength of the photocatalytic centers. In certain embodiments, the emission spectrum of the spectral conversion additives overlaps the absorption spectrum of the photocatalytic centers over a wavelength band of at least 5 nanometers, at least 10 nanometers, at least 20 nanometers, or greater than 50 nanometers. In certain embodiments, dopant selection is performed such that at least 5 percent, at least 10 percent, at least 20 percent, or at least 50 percent of emitted photons fall within a wavelength region where the photocatalytic centers exhibit measurable absorption. The spectral conversion additives may therefore be selected based on measured or published absorption spectra of the photocatalytic centers to increase photon utilization efficiency relative to an unmodified incident spectrum.

[0129] 2. Numerical Aperture And Escape Cone Design Rule

[0130] In certain embodiments, refractive index contrast between the inner optical core and surrounding regions is selected to (i) support longitudinal optical power delivery and (ii) increase radial extraction of spectrally converted emission into the porous layer. For a step index structure, numerical aperture (NA) may be approximated as NA = sqrt(n_coreA2 -n_claddingA2), and for small index contrast as NA « sqrt(2 * n_core * Delta N), where Delta N = n core - n cladding. In certain embodiments, the refractive index difference (Delta N) between the inner optical core and the cladding is selected between 0.0005 and 0.20, between 0.002 and 0.10, or between 0.005 and 0.06. In certain embodiments, the numerical aperture(NA) is selected between 0.05 and 0.90, between 0.07 and 0.40, or between 0.10 and 0.30. In one exemplary configuration using n_core of about 1.45 to 1.55 and Delta N between 0.002 and 0.05, NA is about 0.07 to 0.40. In another exemplary configuration using higher index core glasses (including heavy metal oxide hosts) with n_core of about 1.70 to 2.00 and Delta N between 0.01 and 0.20, NA may be about 0.20 to 0.90. Consistent with the design rules described herein, the index contrast and cladding configuration may be further selected to increase photon escape probability of isotropically emitted light from rare earth spectral conversion centers, including by reducing effective index contrast at one or more interfaces, using graded index or leaky cladding configurations, and / or selecting cladding refractive index to increase transmission of emitted wavelengths into the porous layer while maintaining longitudinal delivery of excitation light. In certain embodiments, the refractive index of the cladding and / or porous layer is selected to increase the escape probability of emitted photons by increasing the effective escape cone of photoluminescent emission. In certain embodiments, Delta N may be reduced to promote partial leakage of emitted photons into the porous layer while maintaining longitudinal delivery of excitation light. In certain embodiments, graded index profiles or spatial variation of refractive index may be employed to increase radial photon extraction along the length of the light rod.

[0131] 3. Porosity And Mass-Transport Design Rule

[0132] In certain embodiments, the porous layer is engineered to balance optical interaction length with fluid diffusion and gas transport. The porous layer may have a porosity between 0.3 and 0.95. In certain embodiments, the porous layer may have a porosity between 0.4 and 0.8, between 0.5 and 0.9, between 0.6 and 0.85, or between 0.7 and 0.95. Average pore diameter may be between 10 nanometers and 50 micrometers, between 20 nanometers and 10 micrometers, or between 50 nanometers and 5 micrometers. In certain embodiments, pore size is selected to permit diffusion of water molecules and removal of evolved hydrogen gas while maintaining a high internal surface area for photocatalytic interaction. In certain embodiments, the porous layer thickness is selected between 20 micrometers and 5 millimeters to provide sufficient optical path length for photon absorption while avoiding excessive diffusion resistance. In certain embodiments, pore geometry and thickness areselected such that a majority of photons emitted from the inner optical core enter the porous layer and encounter at least one photocatalytic center before exiting the layer.

[0133] COORDINATED SPECTRAL-OPTICAL-MASS TRANSPORT OPTIMIZATION

[0134] In certain embodiments, the spectral matching rule, numerical aperture and refractive index rule, and porosity and mass-transport rule are implemented together as a coordinated optimization framework. Spectral conversion additives are selected to align emission wavelengths with absorption bands of selected photocatalytic centers. Refractive index contrast and numerical aperture are configured to promote controlled radial photon delivery from the inner optical core toward the porous layer. Porous layer geometry, porosity, and pore size are engineered to balance optical interaction length with diffusion of water and removal of evolved gases. The inner optical core, cladding, and porous layer are co-designed as an integrated photon management and reaction architecture in which spectral conditioning, photon extraction, catalytic interaction, and mass transport are jointly optimized to increase hydrogen generation efficiency relative to systems lacking coordinated spectral, optical, and transport matching.

[0135] DEFINITION OF OPTO-ELECTROLYSIS

[0136] As used herein, the term “opto-electrolysis” refers to hydrogen production from water in which optical energy activates a photocatalytic and / or photoelectrochemical material to drive hydrogen evolution and / or overall water splitting. Opto-electrolysis includes heterogeneous photocatalytic water splitting in which a photocatalytic center absorbs photons and catalyzes hydrogen evolution without an externally applied electrical bias. Opto-electrolysis further includes photoelectrochemical systems in which light absorption generates charge carriers that participate in hydrogen evolution reactions, optionally in the presence of electrical contacts, cocatalysts, redox mediators, membranes, conductive elements, or applied bias. In certain embodiments, opto-electrolysis does not rely on conventional electrode-driven electrolysis powered primarily by grid electricity. Instead, optical energy provides the primary activation energy for hydrogen generation. Opto-electrolysis may include overall water splitting to generate hydrogen and oxygen, hydrogen evolution in the presence ofsacrificial donors, Z-scheme systems, direct or mediator-assisted charge transfer architectures, heterojunction systems, semiconductor photocathodes, semiconductor photoanodes, and combinations thereof. Unless expressly limited in the claims, optoelectrolysis encompasses light-activated catalytic hydrogen production systems in which optical energy is delivered to, absorbed by, and utilized by photocatalytic centers to convert water into hydrogen.

[0137] DEFINITION OF SPECTRAL OVERLAP

[0138] As used herein, the term “overlaps,” when referring to an emission spectrum of spectral conversion additives and an absorption band of photocatalytic centers, means that at least a portion of the emission wavelength range of the spectral conversion additives coincides with at least a portion of the absorption wavelength range of the photocatalytic centers. In certain embodiments, overlap is defined as an intersection between the emission spectrum and the absorption spectrum over a wavelength interval of at least 1 nanometer, at least 5 nanometers, at least 10 nanometers, at least 20 nanometers, at least 50 nanometers, or greater than 100 nanometers. In certain embodiments, overlap is defined by an overlap integral between a normalized emission spectrum and a normalized absorption spectrum that is greater than 0.01, greater than 0.05, greater than 0.1, greater than 0.2, or greater than 0.5. In certain embodiments, overlap is defined such that at least 1 percent, at least 5 percent, at least 10 percent, at least 20 percent, or at least 50 percent of emitted photon intensity falls within a wavelength region where the photocatalytic center exhibits measurable absorption. In certain embodiments, overlap is defined relative to a peak absorption region of the photocatalytic center such that an emission maximum of the spectral conversion additive is within ±200 nanometers, ±100 nanometers, ±50 nanometers, ±25 nanometers, or ±10 nanometers of a peak absorption wavelength of the photocatalytic center. Overlap may be determined using spectrophotometric measurement of absorption and emission spectra under standard laboratory conditions. Unless otherwise specified, overlap does not require complete spectral coincidence and may include partial spectral intersection sufficient to increase photon utilization by the photocatalytic centers relative to an unmodified incident spectrum.LENS

[0139] A lens may comprise any optical element configured to collect, concentrate, collimate, or direct solar radiation. In certain embodiments, a lens may include, but is not limited to, a magnifying lens, convex lens, plano-convex lens, biconvex lens, converging lens, Fresnel lens, aspheric lens, aplanatic lens, achromatic lens, patterned lens, diffractive lens, and / or meta-lens. The lens may be comprised of glass, fused silica, optical glass, polymeric materials, plastics, acrylates, and / or composite materials. In certain embodiments, the lens may incorporate spectral conversion additives including upconversion additives and / or downconversion additives configured to modify the incident solar spectrum prior to optical transmission. The lens may further comprise one or more coatings including anti-reflective coatings, reflective coatings, wavelength-selective coatings, protective coatings, abrasionresistant coatings, hydrophobic coatings, and / or self-cleaning coatings. In certain embodiments, the lens diameter, focal length, numerical aperture, refractive index profile, surface curvature, and coating configuration are selected in coordination with the numerical aperture and core diameter of the downstream optical fiber to satisfy an etendue matching condition. In certain embodiments, the optical etendue of collected solar radiation is matched to the acceptance cone and cross-sectional area of the optical transmission network to reduce optical loss, minimize overfilling of the fiber core, and improve overall solar-to-hydrogen conversion efficiency.

[0140] ELEMENTS AND OXIDATION STATES

[0141] Elements may be incorporated into any component, part, cable, fiber, coupler, waveguide, lens, collimator, reactor element, porous layer, spectral conversion additive, photocatalytic center, or other system component of the opto-electrolysis hydrogen plant 1200. Elements may include, but are not limited to: Scandium (Sc), Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu), Cadmium (Cd), Indium (In), Gallium (Ga), Selenium (Se), Tellurium (Te), Cesium (Cs), Thorium (Th), Lead (Pb), Tin (Sn), Titanium (Ti), Copper (Cu), Gold (Au), Silver (Ag), Arsenic (As), Silicon (Si), Germanium (Ge),Boron (B), Phosphorus (P), Oxygen (O), Carbon (C), Sulfur (S), Aluminum (Al), Zinc (Zn), Nitrogen (N), Hydrogen (H), Iron (Fe), Manganese (Mn), Cobalt (Co), Chromium (Cr), Bismuth (Bi), Antimony (Sb), Calcium (Ca), Sodium (Na), Lithium (Li), Potassium (K), Molybdenum (Mo), Rhenium (Re), Osmium (Os), Strontium (Sr), Tantalum (Ta), Tungsten (W), Zirconium (Zr), Magnesium (Mg), and lanthanide elements represented as Ln. Each element incorporated into the inner optical core, cladding, porous layer, spectral conversion additive, and / or photocatalytic center may exist in one or more oxidation states consistent with its known chemical valence behavior under the operating conditions of the system. An oxidation state may be represented as E11+or E11”, where E denotes the elemental symbol and n denotes the magnitude of the oxidation state. In certain embodiments, oxidation states include -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5, +6, +7, or +8, provided such states are chemically stable or metastable in the selected host composition and environment. In certain embodiments, rare earth elements may be present predominantly in a +3 oxidation state, including Ce3+, Yb3+, Er3+, Dy3+, Ho3+, Tm3+, Eu3+, Y3+, La3+, and lanthanide ions represented as Ln3+. In certain embodiments, thulium (Tm) may be incorporated into the inner optical core as a spectral conversion additive and may participate in upconversion processes, including Yb3+^-Tm3+energy transfer pathways, to convert near-infrared excitation into shorter-wavelength emission suitable for activation of selected photocatalytic centers. In certain embodiments, transition metals may be present in oxidation states selected from +2, +3, +4, +5, or +6, depending on the selected compound, glass composition, and chemical environment. Examples include Ti2+, Ti3+, Ti4+, Fe2+, Fe3+, Mn2+, Mn3+, Co2+, Co3+, Ni2+, Mo3+, MO4+, Re4+, Os4+, and Cr3 +. In certain embodiments, the selected oxidation state influences one or more of optical absorption behavior, emission wavelength, radiative and non-radiative relaxation pathways, energy-transfer efficiency, band alignment, redox potential, charge-transfer characteristics, photocatalytic activity, and / or hydrogen evolution efficiency within the opto-electrolysis light rod.

[0142] DOPANT PAIRINGS AND ROLE SWITCHING IN SPECTRAL CONVERSION ADDITIVESIn certain embodiments, spectral conversion additives comprise one or more luminescent ions incorporated into a host glass or related optical material, where performance is governed not only by the identity of each ion but also by dopant pairing, excitation wavelength, energy transfer pathways, dopant concentration, and host composition. A given element may function as an upconversion contributor in one pairing and as a downconversion contributor in another pairing because the dominant energy transfer mechanism depends on energy level alignment, pump wavelength, and interaction between neighboring ions. In certain embodiments, a first ion may function as a sensitizer and a second ion may function as an activator. A sensitizer may be selected for high absorption cross section at a desired excitation wavelength, including near infrared, visible, or ultraviolet wavelengths. An activator may be selected for emission at a wavelength band that overlaps with an absorption band of a selected photocatalytic center. Energy transfer between sensitizer and activator may occur through energy transfer upconversion (ETU), excited state absorption (ESA), cross relaxation (CR), or other radiative or non-radiative mechanisms. In certain embodiments, upconversion (anti-Stokes emission) may be achieved by pairing a sensitizer that absorbs lower energy photons with an activator that emits higher energy photons. For example, ytterbium (Yb3+) may serve as a sensitizer under near infrared excitation and may transfer energy to erbium (Er3+), holmium (Ho3+), or thulium (Tm3+) as activators to generate visible or shorter wavelength emission. In such pairings, Yb3+primarily absorbs pump radiation while the activator ion emits spectrally shifted photons. In certain embodiments, the same ion may function differently depending on pairing. For example, Yb3+may act as a sensitizer in an upconversion system when paired with Er3+, Ho3+, or Tm3+, but may act as an energy acceptor and emitter in a downconversion or photon cutting configuration when paired with a higher energy absorbing ion such as Ce3+, Pr3+, or Tb3+. Similarly, neodymium (Nd3+) may function as a sensitizer under one excitation wavelength and as an intermediate energy transfer ion in another architecture. In certain embodiments, downconversion (Stokes shifting) may be achieved by selecting a dopant that absorbs higher energy photons and emits lower energy photons with a Stokes shift. In certain embodiments, quantum cutting or cooperative energy transfer mechanisms may convert one higher energy photon into two lower energy photons when energetically permitted by the paired energy levels of donor andacceptor ions. In certain embodiments, dopant pairing is selected in coordination with the host glass composition. Host properties including phonon energy, field strength, site symmetry, redox environment, and dopant solubility may influence radiative efficiency, multiphonon relaxation rates, cross relaxation probability, concentration quenching thresholds, and energy migration behavior. Lower phonon energy hosts may reduce non-radiative decay and improve upconversion efficiency. Dopant concentration ratios may be selected to maximize energy transfer probability while minimizing clustering and quenching. In certain embodiments, the ratio of sensitizer to activator is selected to optimize absorption, energy transfer efficiency, emission intensity, and spectral overlap with the selected photocatalytic center in accordance with the spectral matching design rule disclosed herein. Representative non-limiting pairings include Yb3+ / Er3+, Yb3+ / Ho3+, Yb3+ / Tm3+, Nd3+ / Yb3+ / Er3+, Ce3+ / Tb3+, Pr3+ / Yb3+, and Tb3+ / Yb3+, although other rare earth and transition metal combinations may be used. The function of any particular element as an upconversion element, downconversion element, sensitizer, activator, donor, acceptor, or intermediate transfer ion depends on excitation band, energy level alignment, host composition, and dopant concentration. Accordingly, in certain embodiments, designation of an element as a conversion element or downconversion element is not intrinsic to the element itself but is determined by its pairing configuration, excitation conditions, and host environment within the inner optical core of the opto-electrolysis light rod.

[0143] SPECTRAL CONVERSION ADDITIVES: UPCONVERSION AND DOWNCONVERSION

[0144] Spectral conversion refers to modification of an incident light spectrum through absorption and re-emission processes that alter photon energy prior to interaction with photocatalytic centers. In certain embodiments, spectral conversion comprises upconversion. Upconversion refers to a process in which absorption of one or more photons results in emission at a shorter wavelength than the excitation wavelength. Examples include conversion of infrared or near infrared radiation to visible radiation. In certain embodiments, spectral conversion comprises downconversion. Downconversion refers to a process in which absorption of one or more photons results in emission at a longer wavelength than the excitation wavelength. Examples include conversion of ultraviolet radiation to visible radiation. In certainembodiments, spectral conversion additives are incorporated into the inner optical core of the opto-electrolysis light rod. In certain embodiments, spectral conversion additives may additionally or alternatively be incorporated into the cladding, waveguide, lens, collimator, power-over-fiber cable, coupler, porous layer, or combinations thereof. In certain embodiments, spectral conversion additives are positioned upstream of the porous photocatalytic layer such that emitted photons propagate radially outward toward photocatalytic centers. Spectral conversion additives may comprise rare earth ions, transition metal ions, mixed-valence ions, coordination complexes, element oxides, doped glass compositions, doped nanoparticles, organic luminophores, polycyclic aromatic hydrocarbons, perylene derivatives, coronene derivatives, or combinations thereof. In certain embodiments, rare earth ions are present in a +3 oxidation state and include Ce3+, Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Nd3+, Sm3+, Y3+, La3+, and other lanthanide ions represented as Ln3+. In certain embodiments, dopant pairs such as Yb3+ / Er3+, Yb3+ / Tm3+, Yb3+ / Ho3+, or related sensitizer-activator systems may facilitate multiphoton upconversion through energy transfer mechanisms. In certain embodiments, cooperative sensitization, cross relaxation, or photon avalanche mechanisms may contribute to nonlinear emission behavior. In certain embodiments, downconversion may occur through radiative relaxation, quantum cutting, charge transfer transitions, defect-mediated emission, or energy transfer between paired dopants. In certain embodiments, transition metal ions including Mn4+, Ti3+, Ni2+, Mo3+, Re4+, Os4+, Cr3+, or Fe3+may participate in absorption and emission processes depending on host composition and coordination environment. In certain embodiments, a desired light spectrum refers to a wavelength distribution that increases photon utilization by selected photocatalytic centers. Spectral conversion additives may therefore be selected such that at least a portion of emitted photon intensity overlaps an absorption band of the photocatalytic centers, thereby increasing hydrogen generation efficiency relative to an unmodified incident spectrum. In certain embodiments, the selection, pairing, concentration, and spatial placement of spectral conversion additives are configured to satisfy the spectral matching design rule described herein.

[0145] RARE EARTH DOPED CORE GLASS EMBODIMENTSIn certain embodiments, the inner optical core 101 comprises a rare earth doped glass configured to function as a spectral conversion medium. The core glass may comprise silica, germanosilicate, aluminosilicate, phosphate, fluorophosphate, fluorozirconate, chalcogenide, sulfide, selenide, or telluride glass as a host matrix. Rare earth dopants may include one or more of Yb, Er, Tm, Ho, Nd, Dy, Eu, Ce, La, Pr, or combinations thereof. In certain embodiments, the dopant system comprises a sensitizer activator pair including but not limited to Yb3+ / Er3+, Yb3+ / Tm3+, Yb3+ / Ho3+, Nd3+ / Yb3+, or Nd3+ / Yb3+ / Er3+systems. In certain embodiments, cooperative upconversion, cross relaxation, energy transfer upconversion, excited state absorption, or avalanche upconversion processes may occur depending on dopant concentration and host composition. Total rare earth concentration in the inner optical core may be between 0.01 mol percent and 10 mol percent, between 0.05 mol percent and 5 mol percent, or between 0.1 mol percent and 2 mol percent. Sensitizer to activator ratios may be selected between 1:10 and 20:1, between 1:5 and 10:1, or between 2:1 and 5:1 to control emission wavelength distribution, emission intensity, and quantum efficiency. The rare earth doped core may be configured such that at least five percent of emitted photon intensity falls within a wavelength range corresponding to at least ten percent of a peak absorption coefficient of the selected photocatalytic centers in porous layer 107. In certain embodiments, the emission peak of the core is within 1 nanometer to 150 nanometers of the peak absorption wavelength of the photocatalytic centers, and in certain embodiments within 1 nanometer to 50 nanometers of the peak absorption wavelength. The rare earth dopants may increase the refractive index of the inner optical core relative to cladding 102, thereby contributing to numerical aperture selection consistent with the escape cone design rule described herein. The refractive index of the doped core may be between 1.45 and 1.95 depending on host composition and dopant loading. The core glass may be fabricated using modified chemical vapor deposition, outside vapor deposition, vapor axial deposition, solution doping, rod in tube processing, preform fabrication and fiber draw techniques, melt quench processing, or extrusion followed by fiber drawing.

[0146] HIGH INDEX CHALCOGENIDE OR PHOSPHATE CORE EMBODIMENTIn certain embodiments, the inner optical core 101 comprises a high refractive index glass selected to enhance absorption cross section, increase emission probability, modify phonon energy environment, or increase numerical aperture relative to cladding 102. The host glass may comprise phosphate glass, fluorophosphate glass, tellurite glass, germanate glass, chalcogenide glass, sulfide glass, selenide glass, or telluride glass. In certain embodiments, the refractive index of the host glass may be between 1.6 and 2.5, between 1.7 and 2.3, or between 1.8 and 2.2. Low phonon energy hosts such as chalcogenide or tellurite glasses may reduce non radiative multiphonon relaxation losses and enhance upconversion efficiency. Phosphate and fluorophosphate glasses may support higher rare earth solubility while maintaining optical clarity and mechanical stability. Rare earth dopants incorporated into high index hosts may include Yb3+, Er3+, Tm3+, Ho3+, Nd3+, Dy3+, Eu3+, or combinations thereof. Dopant concentration may be between 0.01 mol percent and 15 mol percent, between 0.1 mol percent and 10 mol percent, or between 0.5 mol percent and 5 mol percent depending on host glass solubility limits and quenching thresholds. In certain embodiments, the higher refractive index of the core relative to cladding 102 may produce a numerical aperture between 0.05 and 1.2 depending on index contrast. The index contrast may be selected to balance internal guidance with radial emission into porous layer 107. In certain embodiments, the host composition and dopant system may be selected such that emission spectra are engineered to satisfy the spectral matching design rule described herein, including matching emission peaks to within 1 nanometer to 150 nanometers of the absorption maxima of the photocatalytic centers. These embodiments provide structurally integrated spectral conversion within the inner optical core while enabling control over emission efficiency, spectral position, refractive index, numerical aperture, and radial photon extraction toward the porous photocatalytic layer.

[0147] LIGHT AND ELECTROMAGNETIC RADIATION

[0148] Light, as used herein, may refer to electromagnetic radiation across any portion of the electromagnetic spectrum. Electromagnetic radiation may include ultraviolet (UV), visible light, near infrared (NIR), infrared (IR), far infrared, microwave radiation, radio frequency radiation, x-rays, gamma rays, and thermal radiation. In certain embodiments, the systemprimarily utilizes solar radiation comprising ultraviolet, visible, and near infrared wavelengths. In other embodiments, artificial sources may emit electromagnetic radiation in selected spectral bands. Electromagnetic energy, as used herein, may refer to energy carried by electromagnetic radiation in any of the foregoing wavelength ranges.

[0149] LIGHT SCATTERING CENTERS

[0150] Glass, fiber, coatings, and any component of the OELR 100 or opto electrolysis hydrogen plant may include light scattering centers. Light scattering centers may comprise voids, gas-filled cavities, particles, aggregates, quantum dots, nanoparticles, phase-separated domains, or refractive index inhomogeneities. Voids may contain air, vacuum, argon, nitrogen, helium, oxygen, carbon dioxide, hydrogen, or other gases. Alight scattering center may be a region having a refractive index different from surrounding material and may cause deviation of photons from axial propagation. Scattering may occur within bulk material, at interfaces, at surfaces, or within porous regions. In certain embodiments, scattering centers are configured to promote radial propagation of light toward the cladding, porous layer, and photocatalytic centers. Scattering magnitude, angular distribution, and wavelength selectivity may be controlled by adjusting size, distribution, density, and refractive index contrast to increase photon interaction with the photocatalytic centers.

[0151] OPTO ELECTROLYSIS

[0152] Opto electrolysis may refer to hydrogen evolution resulting from interaction of light, water or a water mixture, and one or more photocatalytic centers. In certain embodiments, hydrogen is generated when incident photons are absorbed by a photocatalyst, resulting in charge separation and catalytic conversion of water into hydrogen and oxygen. System performance may be influenced by additional parameters including reactor configuration, water composition, dissolved species, additives, temperature, pH, ionic strength, fluid dynamics, mass transport, turbidity, photon flux, photocatalytic activity, and photocatalyst stability or lifetime. Opto electrolysis as used herein includes photochemical, photocatalytic, photoelectrochemical, and light-assisted catalytic hydrogen generation processes operating within the disclosed optical delivery architectures.PHOTOCATALYTIC CENTERS

[0153] A photocatalytic center may be a composition that accelerates conversion of water into hydrogen in the presence of photons. A photocatalytic center may be used for (i) photocatalytic hydrogen evolution (HER), (ii) overall water splitting (OWS), and / or (iii) photoelectrochemical (PEC) hydrogen generation in which light absorption generates charge carriers that participate in electrochemical half-reactions, optionally with cocatalysts, protective layers, membranes, redox mediators, electrolytes, and / or applied bias. In certain embodiments, photocatalytic centers may include metal oxides, oxynitrides, nitrides, sulfides, selenides, carbon nitride materials, and semiconductor junction materials, including mixtures, doped forms, defect-engineered forms, nanostructured forms, composites, heterojunctions, and / or protected forms thereof. Examples of photocatalytic centers include, but are not limited to: TiO2, SrTiO3, NaTaO3, WO3, Fe2O3, BiVO4, ZnO, Ta2O5, Nb2O5, TaON, Ta3N5, g-C3N4, CdS, ZnS, ZnIn2S4, CuInS2, Cu2ZnSnS4, MoS2, and WS2. In certain embodiments, photocatalytic centers may further include PEC semiconductor photocathodes and / or photoanode materials, including but not limited to Si, Cu2O, GaN, InGaN, GaAs, and InP, including protected junctions, tandem junctions, stacked junctions, and / or heterojunction architectures. In certain embodiments, one or more cocatalysts may be included and / or deposited on photocatalytic centers to enhance charge transfer and reaction kinetics.

[0154] Cocatalysts may include, but are not limited to: Pt, Pd, Ru, Rh, Ir, Ni, Co, Fe, Mo, W, Cu, and compounds thereof including Ni2P, cobalt phosphides, molybdenum sulfides, tungsten sulfides, and mixtures thereof. Cocatalysts may be present as nanoparticles, clusters, islands, thin films, conformal coatings, and / or dispersed phases within porous layer 107, on pore surfaces 111, and / or on exterior surfaces of porous layer 107. In certain embodiments, photocatalytic centers may be protected by a stability layer including oxide, nitride, carbide, carbon, polymer, sol-gel, atomic layer deposition (ALD), chemical vapor deposition (CVD), electroless, and / or other conformal protective coatings that reduce corrosion and / or photocorrosion while permitting diffusion of water and gases and enabling charge transfer.

[0155] CABLE AND FIBER COATINGA cable and / or fiber coating may comprise a single-layer coating, a dual-layer coating, or a multi-layer coating structure. The coating may be applied to a PoF cable, an OELR component, an optical fiber, or any optical transmission element within the opto-electrolysis hydrogen plant 1200. In certain embodiments, the coating comprises a polymeric material. The polymer may include, but is not limited to, acrylates, polyacrylates, acrylic polymers, methacrylates, polymethacrylates, acrylonitrile, polyacrylonitrile, acrylamide, polyacrylamide, polyether ether ketone (PEEK), styrene, polystyrene, amides, polyamides, silicones, polysilicones, fluoropolymers, epoxy-based polymers, urethane-based polymers, and / or combinations thereof In certain embodiments, a multi-layer coating may include a primary inner coating configured for adhesion and flexibility and a secondary outer coating configured for mechanical protection, environmental resistance, thermal stability, chemical resistance, and / or optical confinement. Additional layers may provide UV resistance, moisture barrier properties, hydrogen barrier properties, abrasion resistance, or index engineering for optical performance. The coating may further include additives such as stabilizers, UV absorbers, thermal stabilizers, fillers, nanoparticles, pigments, lightscattering centers, spectral conversion additives, and / or adhesion promoters.

[0156] HIGH CAPACITY PoF CABLE

[0157] A high capacity PoF cable may be an optical cable configured to transmit optical power 0<W) exceeding conventional communication fiber power levels. In certain embodiments, 0<w> may be greater than 30 watts, 50 watts, 80 watts, 100 watts, 150 watts, 200 watts, 300 watts, 400 watts, 500 watts, 600 watts, 700 watts, 800 watts, 900 watts, 1 kW, 2 kW, 5 kW, 10 kW, 25 kW, or 50 kW. In certain embodiments, the high capacity PoF cable is configured to transmit said optical power over a length of at least 10 ft, 50 ft, 100 ft, 250 ft, 500 ft, 1,000 ft, 2,000 ft, or greater than 1,000 ft. In certain embodiments, the cable may comprise a core diameter, refractive index profile, numerical aperture, coating system, and thermal management configuration selected to reduce optical loss, mitigate nonlinear effects, limit thermal accumulation, and maintain structural integrity during sustained high power transmission.

[0158] POROUS LAYER COMPOSITIONPorous layer 107 may be comprised of inorganic, organic, polymeric, ceramic, or hybrid materials. In certain embodiments, porous layer 107 may comprise glass, silica (SiO2), alumina (A12O3), titanium dioxide (TiO2), zirconia (ZrO2), ceramic materials, zeolites, metal-organic frameworks (MOFs), aerogels, foams, or hybrid inorganic-organic materials. In certain embodiments, porous layer 107 may comprise polymeric materials including PEEK, polyethersulfone (PES), polysulfone (PSU), polyvinylidene fluoride (PVDF), polypropylene (PP), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), cellulose acetate (CA), polyethylene (PE), polystyrene (PS), polystyrene-divinylbenzene (PS-DVB), electrospun nanofibers, and / or combinations thereof. In certain embodiments, porous layer 107 may comprise a membrane structure, microfiltration structure, ultrafiltration structure, nanofiltration structure, chromatography media structure, aggregated bead structure, monolith structure, fibrous media structure, separation media structure, porous ceramic structure, zeolite structure, molecular sieve structure, MOF structure, open-cell foam structure, and / or aerogel structure. Porous layer 107 may further comprise photocatalytic centers 109, 110, cocatalysts, spectral conversion additives, and / or light scattering centers distributed within the scaffold and / or on pore surfaces.

[0159] SURFACE PORES

[0160] Surface pores refer to pores located at or near the external surface of porous layer 107 that promote diffusion of the water mixture into porous layer 107 and diffusion of evolved hydrogen and / or oxygen gas out of porous layer 107. Surface pores may be comprised of the same material as porous layer 107 and may be engineered in size, density, and distribution to improve mass transport and catalytic accessibility.

[0161] UNITS: ft equals foot, m equals meter, um equals micrometer, mm equals millimeter, mi equals mile, in equals inch, nm equals nanometer, kW equals 1,000 watts, MT equals metric tons, kg equals kilograms, g equals grams

Claims

AMENDED CLAIMSreceived by the International Bureau on 16 Jun 2026 (16.06.2026) AMENDED CLAIMSThis complete set of claims replaces claims 1-23 originally filed.What is claimed is:

1. An optically activated hydrogen generation light rod comprising:an inner optical core extending along a longitudinal axis;a cladding surrounding at least a portion of the inner optical core; anda porous layer positioned radially outward of at least a portion of the cladding,wherein:the inner optical core comprises one or more rare-earth dopants configured to absorb incident light at a first wavelength range and emit light at a second wavelength range different from the first wavelength range;the porous layer comprises photocatalytic centers configured to convert water into hydrogen in the presence of light;the one or more rare-earth dopants are selected such that the first wavelength range has reduced overlap with an absorption band of the photocatalytic centers and the second wavelength range emitted from the inner optical core spectrally overlaps, as defined herein, with the absorption band of the photocatalytic centers;the porous layer comprises a monolithic porous structure formed in situ around the cladding by polymerization or sol-gel processing; andthe porous layer has a pore size and a porosity selected to permit diffusion of water and evolved hydrogen while maintaining an optical path length sufficient to promote absorption of spectrally converted light by the photocatalytic centers.

2. The light rod of claim 1, wherein the one or more rare-earth dopants are configured to provide upconversion of incident light.

3. The light rod of claim 1, wherein the one or more rare-earth dopants are configured to provide downconversion of incident light.

4. The light rod of claim 1 , wherein the one or more rare-earth dopants comprise both upconversion and downconversion dopants.

5. The light rod of claim 1, wherein the inner optical core further comprises light scattering centers configured to promote radial propagation of emitted light toward the porous layer.<IMG file=null he=null id=imgf000053_0001 img-content=null img-format=null inline=null orientation=null wi=null>

6. The light rod of claim 1, wherein radial propagation of emitted light occurs at least in part by isotropic photoluminescent emission from the one or more rare-earth dopants without discrete engineered scattering structures.

7. The light rod of claim 1, wherein the photocatalytic centers comprise one or more of TiO2, Cu2O, CdS, ZnO, ZnS, MoS2, SrTiO3, BiVO4, or combinations thereof.

8. The light rod of claim 1, wherein the one or more rare-earth dopants are selected to emit light within a peak absorption region of the photocatalytic centers.

9. The light rod of claim 1, wherein the porous layer has a porosity between 0.3 and 0.95 and is configured to permit diffusion of water and evolved hydrogen.

10. The light rod of claim 1, wherein the monolithic porous structure is cured to form a self- supporting porous scaffold surrounding the cladding.

11. The light rod of claim 10, wherein the porous layer comprises a silica-based porous monolith formed by a sol-gel process.

12. The light rod of claim 10, wherein the porous layer comprises a polymer-based porous monolith formed using a porogen to define pore size.

13. The light rod of claim 12, wherein the porous layer comprises a polystyrene-based monolith formed using a porogen selected to produce pores having an average diameter between 2 nanometers and 100 micrometers.

14. The light rod of claim 10, wherein the porous layer has an average pore size between 2 nanometers and 200 nanometers, between 0.1 micrometers and 10 micrometers, or between 10 micrometers and 100 micrometers.

15. The light rod of claim 10, wherein the monolithic porous structure is formed around the optical core and cladding within a casing and shrinks during curing to mechanically engage the cladding.

16. The light rod of claim 10, wherein the photocatalytic centers are incorporated into the porous monolithic structure during formation.

17. The light rod of claim 10, wherein the photocatalytic centers are deposited onto pore surfaces of the porous layer after formation of the porous monolithic structure.

18. The light rod of claim 17, wherein the photocatalytic centers are attached to the porous layer via electrostatic interaction between oppositely charged surface groups.

19. The light rod of claim 1, wherein the porous layer has a porosity between 0.4 and 0.9 and a pore size selected to permit diffusion of water and evolved hydrogen while maintaining an optical path length sufficient to promote absorption of spectrally converted light.

20. An optically activated hydrogen production system comprising:a light source configured to provide incident light, wherein the light source comprises a solar radiation collection assembly configured to collect solar radiation;an optical transmission network configured to deliver optical power;at least one light rod according to claim 1 optically coupled to the optical transmission network; anda reactor configured to contact water with the porous layer of the light rod to produce hydrogen.

21. The hydrogen production system of claim 20, wherein the optical transmission network comprises one or more optical fibers configured to deliver optical power over fiber.AMENDED SHEET (ARTICLE 19)22. The hydrogen production system of claim 20, wherein the reactor comprises a reactor core containing a plurality of light rods arranged in an array.

23. The hydrogen production system of claim 22, wherein the plurality of light rods are arranged in reactor element assemblies supported by one or more grid plates.<IMG file=null he=null id=imgf000055_0001 img-content=null img-format=null inline=null orientation=null wi=null>STATEMENT UNDER ARTICLE 19 (1) STATEMENT UNDER ARTICLE 19(1)Applicant submits amended claims 1-23 under Article 19.Amended claim 1 clarifies the disclosed spectral-engineering relationship between the inner optical core and the porous photocatalytic layer. In particular, claim 1 now recites that the inner optical core comprises rare-earth dopants configured to absorb incident light at a first wavelength range and emit light at a second wavelength range different from the first wavelength range. The rare-earth dopants are selected such that the first wavelength range has reduced overlap with an absorption band of the photocatalytic centers and the emitted second wavelength range spectrally overlaps with the absorption band of the photocatalytic centers.Amended claim 1 further incorporates the monolithic porous layer limitation and the pore-size / porosity optical-and-mass-transport limitation previously recited in the originally filed claims. Thus, the amended claim clarifies that the porous layer is a monolithic porous structure formed around the cladding and has pore characteristics selected to permit diffusion of water and evolved hydrogen while maintaining optical path length for absorption of spectrally converted light.With respect to amended claim 1 , Zhongying discloses a photoelectric hydrolysis fiber having photovoltaic and electrode structures, but does not disclose rare-earth dopants in an optical core selected to convert incident wavelengths having reduced overlap with photocatalytic centers into emitted wavelengths that spectrally overlap an absorption band of photocatalytic centers in a monolithic porous layer.With respect to amended claim 1, Westerhoff and Peill disclose photocatalyst-coated optical fibers, but do not disclose the amended spectral-conversion relationship between rare-earth dopants in the inner optical core and photocatalytic centers in the monolithic porous layer.The amendments do not require amendment of the description or drawings.

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