An obscure Japanese research paper, some second-hand equipment on eBay, and a British scientist's argument with his wife have become the catalysts for creating the world's first room-temperature microwave laser. It's also around 100 million times more powerful than current models.
Masers (Microwave Amplification by Stimulated Emission of Radiation) have been around for decades and use stimulated microwaves, as opposed to light in lasers, to produce an output. Masers are rarely used these days, largely for practical reasons, since they require magnetic shielding and cryogenic temperatures to work.
Source: The Register. Read full article. (link)