Modelling the light transport in LED-pumped masers

“MASERs” (Microwave Amplification by Stimulated Emission of Radiation) are devices that can amplify and detect extremely weak electromagnetic signals. Potential applications include more sensitive variants of 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 demonstrate room temperature operation in both pulsed and continuous waves using solid-state materials and laser pumping. A key research challenge is to replace the pump laser by a more rugged and low-cost system. Due to their low brightness, LEDs are not adapted easily to pump masers. However, LED-pumped luminescent concentrators (LED-LC) are perfect for this purpose, which is low-cost, low maintenance and simple fabrication. This work will analyse the optical pumping dynamics of the LED-pumped maser using Monte Carlo raytracing of LED-LC light guides, performed using LightTools® Illumination design software. The power coupled into the maser crystal cannot be measured directly once it is glued to the luminescent concentrator. LightTools will be used to estimate this value to optimise the output power of the concentrator, by modelling concentrators coupled to the maser gain medium. The design will be optimised with different resonator designs (CST Studio Suite®), coupling scenarios and extraction optics. Different excitation techniques and geometries will be trailed, such as transverse pumping and longitudinal pumping of the maser.