A Systems Theory Approach to the Synthesis of Minimum Noise Phase-Insensitive Quantum Amplifiers
For quantum optics engineers, this offers a practical method to build optimal amplifiers, though the result is incremental as it builds on known noise bounds.
The paper provides a systems theory proof of the minimum noise bound for phase-insensitive quantum amplifiers and presents a synthesis procedure to construct an amplifier achieving that bound with required gain and bandwidth. The design uses two squeezers and two beamsplitters.
We present a systems theory approach to the proof of a result bounding the required level of added quantum noise in a phase-insensitive quantum amplifier. We also present a synthesis procedure for constructing a quantum optical phase-insensitive quantum amplifier which adds the minimum level of quantum noise and achieves a required gain and bandwidth. This synthesis procedure is based on a singularly perturbed quantum system and leads to an amplifier involving two squeezers and two beamsplitters.