Broadband Self-calibrated Rydberg-based RF Electric Field and Power Sensor

Initial research and development towards a self-calibrated Rydberg-atom-based electric-field and power sensor for microwave and THz radiation is conducted. The sensor operates on atomic-physics and quantum-optics principles, especially electromagnetically induced transparency. Infrared and visual solid-state laser systems are employed to measure the energy levels of Rydberg atoms in room-temperature rubidium vapor cells exposed to the radiation. The observed level shifts and the applied field strength stand in a unique relation that only depends on invariable atomic parameters, not on technical calibration factors. In contrast to traditional instruments, this sensor is calibration-free and does not require an antenna. In the first task, the response of the sensor to strong radiation fields is quantitatively evaluated. The high-field response of the atoms is nonlinear and requires an advanced quantum-physics model known as Floquet theory. The performing company already uses such a model and will develop it further. In the second task, the sensors performance over a frequency range up to 250GHz is evaluated, and in the third task (Phase 1 option) solutions to the problem of atomic vapor-pressure variation are sought. The research includes the development of designs and concepts that will eventually lead to a portable prototype.