I think microwave ovens usually use mangetrons rather than masers: https://en.wikipedia.org/wiki/Cavity_magnetron https://en.wikipedia.org/wiki/Cavity_magnetron

I think microwave ovens usually use mangetrons rather than masers: https://en.wikipedia.org/wiki/Cavity_magnetron https://en.wikipedia.org/wiki/Cavity_magnetron It's true though that both of them are coherent microwave sources. And the magnetron is arguabbly more "laser-like" than a maser.