A 2-Gbps low-SWaP quantum random number generator with photonic integrated circuits for satellite applications

Area of Science:

• Quantum optics
• Integrated photonics
• Quantum information science

Background:

• Quantum random number generators (QRNGs) are crucial for secure communication.
• Existing QRNGs often face limitations in size, power consumption, and speed.
• Integrated photonic solutions offer potential for miniaturization and efficiency.

Purpose of the Study:

• To introduce a novel, low size, weight, and power (SWaP) quantum random number generator (QRNG).
• To demonstrate a practical QRNG suitable for resource-constrained environments, such as space-based quantum key distribution (QKD).

Main Methods:

• Utilized compact integrated photonic asymmetric Mach-Zehnder interferometers (AMZIs).
• Employed phase-diffusion in two gain-switched lasers interfered within chip-AMZIs.
• Replaced high-bit analog-to-digital converters with clocked comparators and used XOR operations to reduce complexity and power.

Main Results:

• Achieved a QRNG with low overhead power consumption of 7.93 W.
• Demonstrated fast random number generation at rates up to 2 Gbps.
• Successfully seeded a free-space decoy-state quantum key distribution system in real-time.

Conclusions:

• The developed QRNG offers a practical solution for low-power, high-bit-rate random number generation.
• This advancement is significant for practical QRNG implementation, especially in space-based QKD.
• The integrated photonic approach enables efficient and compact QRNGs for demanding applications.