At Allegro and Eindhoven University of Technology (TU/e), we’re pushing the boundaries of quantum-safe communication by developing a versatile, photonic integrated receiver for quantum key distribution (QKD). This receiver is protocol-flexible, supporting BB84, differential phase shift (DPS), and coherent one-way (COW) QKD schemes.
✨ What’s unique about our design?
We’ve demonstrated a low-loss silicon nitride photonic integrated circuit (PIC) featuring:
- Tunable couplers (TCs) with >35 dB extinction ratio for dynamic protocol switching
- An asymmetric Mach–Zehnder interferometer (AMZI) for phase-sensitive detection
- Spot-size converters (SSCs) for efficient fiber-to-chip coupling
- QBERs as low as 0.5%–1.5%, using off-the-shelf InGaAs SPDs—good enough for high secret key rates (SKRs)
🎛️ The reconfigurability of the TCs enables real-time adjustment of measurement bases and efficient power balancing, enhancing the adaptability and performance of the QKD receiver—an essential step for interoperable and scalable quantum networks.
🔬 Built on silicon nitride, this chip offers a low-loss, thermally stable platform, paving the way for integrated, high-performance quantum photonic systems.
This is a step toward future-proof communication systems, aligning with Europe’s broader vision for secure digital infrastructure.
📚 More technical details are referenced from:
- Meh24 (BB84)
- Ino02 (DPS)
- Stu05 (COW)
- Fat24 (SKR analysis)
#QuantumTech #PhotonicIntegration #QKD #PIC #QuantumSecurity #IntegratedPhotonics #Allegro #TUe #SecureCommunication #QuantumNetworking
