Ultra-precise, Ultra-miniature Optical Clocks Using Frequency Combs

“One of the most exciting breakthroughs in optical physics in 2014 was an improvement in laser technology that could lead to the miniaturization of high-precision clocks, navigation systems and space systems.”

http://kavliblog.org/2014/12/15/biggest-science-stories-2014-microresonator-frequency-combs/