Platform Technology

Our nanoporous DBR solves a 30-year industry challenge

One patented electrochemical process unlocks manufacturable light sources across wavelengths the industry has failed to reach for three decades.

01/The Core Insight
The core insight
GaAs VCSELs dominate 850–940 nm because the AlGaAs/GaAs n-DBR stack delivers ~16% refractive-index contrast for high mirror reflectivity. InP and GaN lattice-matched alloys only offer ~0.3% contrast. InPHRED's nanoporous etching engineers >40% contrast from scratch on the same foundry epi the industry already uses.
02/The Breakthrough

How we solved a 30-year deadlock

A long-standing industry barrier solved by a single, foundry-compatible process.

The industry has been stuck for 30 years
1
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.
2
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.
3
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
✓
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.
✓
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.
✓
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.
Nanoporous n-DBR formation schematic
Figure 1. Selective porosification produces a high-contrast Bragg reflector (Δn ≈ 0.9, R ~ 99.9%)
03/Commercial Performance

World's first mass-market SWIR VCSEL

Production-grade efficiency and single-mode lasing demonstrated on standard foundry-grown InP epi.

1380 nm InP VCSEL performance: optical power, voltage, and PCE vs current with EL spectrum inset
Figure 2. LIV characteristics of the 1380 nm SWIR VCSEL showing ~30% peak PCE and single-mode lasing at 1378 nm
04/Competitive Landscape

No other technology meets the demand for low-cost manufacturability

Compared to all prior InP VCSEL approaches, InPHRED's homoepitaxial nanoporous DBR is uniquely manufacturable at commercial scale and low cost.

Heteroepitaxial DBR
Bandwidth10, RayCan		 AlAs/GaAs on GaAs
IQE		 Wafer fusion
BeamExpress, Trumpf		 Double dielectric DBR
Vertilas		 InPHRED nanoporousOUR APPROACH
DBR epitaxyDifficult heteroepitaxyMature AlGaAsMature AlGaAsN/AHomoepitaxy, mature
Wavelength range1,300–1,600 nmUp to 1,300 nm1,300–1,600 nm1,300–1,600 nm1,300–2,300 nm
Active region✓ Mature⚠ Reliability issues✓ Mature✓ Mature✓ Mature
Monolithic fabWafer-levelWafer-level✗ Not scalable✗ Not scalableWafer-level
Volume production✗ Difficult⚠ Marginal✗ Difficult✗ Difficult✓ Excellent
CostMediumMediumHighHighLow
05/Intellectual Property

A deepening IP moat

Our exclusive license covers the core nanoporous DBR process, application to specific material systems and device geometries, and downstream integration approaches. The portfolio grows with every new application we develop.

Discuss licensing or partnerships →
  • Core porosification process: electrochemical conversion of n⁺-doped InP and GaN layers to nanoporous semiconductor with controlled porosity and index contrast
  • InP VCSEL DBR architecture: nanoporous/dense InP layer pairs forming a homoepitaxial Bragg reflector for SWIR lasing (1,300–2,300 nm)
  • GaN RC-LED for wearables: nanoporous GaN DBR mirrors bounding a visible-light resonant cavity for high-spectral-purity emission (450–570 nm)
  • Additional patentable technologies: 2–4 further patentable innovations developed since our seed round, covering advanced device and process variations

Want to go deeper?

Our technical briefs cover DBR physics, device characterisation data, and application-specific analyses. Request access or reach out to discuss a custom engagement.

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