A maser assembly includes a pump light source; a maser material including molecules that are excited through the absorption of light (1) from the pump light source, and which subsequently transfer via intersystem crossing (9) into the sublevels of their triplet ground states, so causing a population inversion between two sublevels (16,18); an electromagnetic structure in which the masing material is disposed, and which supports a microwave mode that is both resonant in frequency with and magnetically coupled to the transition between these two sublevels; and where energy is supplied to the microwave mode through stimulated emission (25) across the transition at such a rate as to exceed the mode's electromagnetic losses, the microwave mode being a maser mode. The assembly includes provisions for effecting substantially continuous maser activity during operation of the assembly. The laser crystal may be a (perdeuterated) pentacene in p-terphenyl which is held at room temperature without an additional magnetic field and the dye molecules in the single crystal may be pumped by blue LED with a frequency conversion to the yellow and green with the help of a Ce:YAG fluorescent pump light concentrator.
展开▼
