Low-Noise, High-Efficiency Geiger Photodiode for Quantum Cryptography

The mechanics of single photons can be used to entangle information carry quantum states, allowing for quantum computation or random number generation. Quantum communication utilizes the quantum nature of single-photons to retain information, particularly in the form of quantum key distribution protocols. High-efficiency, low-noise single photon detection at high efficiency is critical for the application of new systems utilizing the power of quantum mechanics. Existing Geiger photodiodes provide single photon resolution with excellent timing characteristics and low dark count rates but has limited detection efficiency. This program will develop a Geiger photodiode for quantum cryptography with an efficiency greater than 98% in the visible wavelength range.