Luminescent Concentrators for Next Generation Microwave Photonics

The MASER, acronym for Microwave Amplification by Stimulated Emission of Radiation, was invented around 60 years ago and exploits paramagnetic transitions in quantum systems to amplify radio frequency/microwave signals. Potential applications include more sensitive variants of Electron Paramagnetic Resonance (EPR) spectroscopy, magnetic resonance body scanners, deep-space telecommunications, read-out schemes for spin-based quantum computers, and embodiments of “quantum optics” at microwave and radio frequencies. Recent improvements on masers have demonstrated room-temperature operation in both pulsed and continuous waves using solid-state materials and solid-state laser pumping [1], [2]. A crucial research challenge is to replace the pump laser by a more rugged and low-cost system. LED-pumped luminescent concentrators [3]–[5] are ideal for this purpose. because they are low-cost with simple fabrication and low maintenance.