Invention: This invention describes how to augment a train of bright phase-modulated laser light pulses of a communications system by splitting squeezed light. This can be used to detect minuscule drops in connectivity and channel loss without affecting the communications rate. Connectivity drops in laser or fiber-optic communication systems can occur due to a range of factors, including deliberate intrusion attempts such as wiretapping, as well as more benign or environmental causes. A disturbance may be brief or subtle, but it often disrupts the precise balance of signal transmission, especially in high-sensitivity or secure systems.
Background: Classical laser communications send information by changing properties of laser light, like its brightness or phase, but they are limited by quantum noise. Squeezed light is a special type of quantum light where the noise is reduced in one property, allowing more precise measurements. Adding squeezed light to communication systems can improve how clearly signals are received, especially over long distances or in low-light situations. This not only helps classical systems but also supports quantum communication, which relies on detecting delicate quantum states. Squeezed light can also make the quickest change detection, spotting sudden changes in a signal, faster and more accurately, which is useful in areas such as real-time sensing, security, and system monitoring.
Applications: • Quantum communications • Defense and military communication • Satellite optical links • Hypersensitive environmental sensing • High-frequency trading
Advantages: • Reduced noise • Higher signal-to-noise ratio • Better error correction • Faster change detection • Can be integrated into existing infrastructure