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The Breakthrough
30-year deadlock — and how we solved it
A long-standing industry barrier solved by a single, foundry-compatible process.
The industry has been stuck for 30 years
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GaAs VCSELs dominate NIR (850–980 nm) because AlGaAs/GaAs forms a near-perfect homoepitaxial DBR mirror pair: high refractive-index contrast, mature process, wafer-level testable, low cost. These VCSELs are in every iPhone and LiDAR sensor today.
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InP (SWIR) and GaN (visible) have no equivalent DBR pair. Lattice-matched InP alloys yield only ~0.3% index contrast versus ~16% for AlGaAs/GaAs, far below the ~99.9% mirror reflectivity required to sustain a VCSEL optical cavity. GaN faces the same fundamental barrier.
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All workarounds fail to scale. Heteroepitaxial growth is expensive and defect-prone. Wafer fusion disrupts the monolithic process flow. Double dielectric DBRs require complex post-processing. No competitor has achieved low-cost, wafer-level InP or GaN VCSELs commercially.
InPHRED's patented nanoporous solution
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Electrochemical nanoporous etching selectively converts n⁺-doped semiconductor layers into nanoporous material — reducing local refractive index by a precisely controllable amount, determined entirely by porosity. Undoped layers remain unchanged.
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Homoepitaxial DBR with engineered index contrast. Alternating dense and nanoporous layers create refractive-index steps of up to ~40% (exceeding AlGaAs/GaAs contrast) on standard foundry-grown InP or GaN epi. No exotic materials or wafer fusion are required.
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Drop-in compatible with volume manufacturing. The porosification step is a single post-epi electrochemical process added to a conventional wafer-level flow. We leverage foundry fab and on-wafer testing compatible with the compound semiconductor supply chain.
