Coherence-first photonic architecture
QLT is built around one technical decision: analog coherence should be managed inside the processor. The platform combines Optical Distortion Reversal (ODR), low-loss integrated photonics, and proprietary all-optical switching into a single heterogeneous chip architecture.
Optical Distortion Reversal inside the chip
ODR is QLT's proprietary waveguide geometry that leverages advanced squeezed-light techniques to passively reverse optical distortion as photons traverse sub-micron waveguides. This extends photonic qubit coherence by an order of magnitude at room temperature — without cryogenics or active error correction.
The underlying optical distortion reversal principles have been leveraged in telecom for decades to maintain signal fidelity across thousands of kilometers of fiber. QLT's breakthrough is miniaturizing and adapting these proven techniques into a monolithic photonic quantum processor. The extension of coherence and mitigation of error accumulation are the pivotal factors unlocking photonic quantum computing at scale — and ODR is the key that makes this possible.
Coherence degrades rapidly
As photons move through optical components, signal quality deteriorates. Without intervention, photonic circuits are limited to ~50–100 useful operations before quantum information is lost.
Coherence stays bounded
QLT's proprietary ODR waveguide geometry passively restores coherence at periodic intervals. Circuit depth is limited only by design choice, not physics — enabling 500–1000+ gate circuits at room temperature.
Heterogeneous photonic integration
Three material families, each optimized for its role in the processor.
Silicon Nitride (Si₃N₄)
Ultra-low-loss waveguide routing, interferometers, and delay lines. Thermally stable, CMOS-compatible, foundry-proven at scale.
Loss: 0.1 dB/m class · Athermal · SiO₂ cladding
Proprietary ODR Overlay
Proprietary photonic overlay engineered onto the SiN platform for passive coherence restoration. QLT's waveguide geometry eliminates active thermal tuning and extends qubit lifetime by an order of magnitude — all at room temperature.
γ_eff: ~10–12 W⁻¹m⁻¹ · 55 mm spiral · CW pump ~1550 nm
Proprietary All-Optical Switch
QLT's proprietary femtosecond all-optical transistor enables switching, routing, and adaptive reconfiguration at THz rates — 5,700× faster than electronic CMOS.
<175 fs switching · >30 dB extinction · All-optical · Zero heat
Photonic quantum operations
Dual-rail and time-bin qubits
Primary encoding uses dual-rail path qubits and time-bin qubits — both well-suited to integrated photonic platforms. Frequency-bin encoding available as secondary option.
Interferometric linear optics
The canonical gate model uses interferometric LOQC and fusion-style photonic logic with time-multiplexed hardware reuse. Measurement-based quantum computing protocols supported.
See how this architecture becomes hardware
The manufacturing page covers the foundry-to-package industrial path that turns this photonic architecture into a real product.