title: Enhanced magnetic Purcell effect in room-temperature masers.
abstract: Recently, the world's first room-temperature maser was demonstrated. The maser consisted of a sapphire ring housing a crystal of pentacene-doped p-terphenyl, pumped by a pulsed rhodamine-dye laser. Stimulated emission of microwaves was aided by the high quality factor and small magnetic mode volume of the maser cavity yet the peak optical pumping power was 1.4 kW. Here we report dramatic miniaturization and 2 orders of magnitude reduction in optical pumping power for a room-temperature maser by coupling a strontium titanate resonator with the spin-polarized population inversion provided by triplet states in an optically excited pentacene-doped p-terphenyl crystal. We observe maser emission in a thimble-sized resonator using a xenon flash lamp as an optical pump source with peak optical power of 70 W. This is a significant step towards the goal of continuous maser operation.
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Breeze
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Ke-Jie
authors.initials: KJ
authors.lastname: Tan
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Richards
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Juna
authors.initials: J
authors.lastname: Sathian
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Oxborrow
authors.affiliation: Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Neil McN
authors.initials: NM
authors.lastname: Alford