Tunable Microwave Radiation Pulse Generation by Excitation of Superconducting Closed-Loop Antennas

An electromagnetic transmitter typically consists of in dividual components such as a power supply, a pulsing source, oscillator, waveguide, and antenna. In this work we circumvent complications associated with connecting these individual components and instead combine them into a nontraditional, photonic enabled, compact transmitter device for pulse-capable and tunable, microwave radiation. This device is presently a centimeter scale, continuous, thin film superconducting ring supporting a persistent super-current charged by induction. An ultrafast laser pulse (required) illuminates the ring (either at a point or uniformly around the ring) and perturbs the super-current by the de-pairing and recombination of Copper pairs. This generates a microwave pulse where both ring and laser pulse properties dictates the radiated spectrum's shape. The transmitting device is self-contained and isolated from conductive components that are observed to interfere with the generated signal. A rich spectrum is observed that extends beyond 30 GHz (equipment limited) and illustrates the complex super-current dynamics bridging optical, THz, and microwave wavelengths.