Scientists in Xinjiang have created the world’s first crystal that can produce the ultraviolet light needed for future thorium nuclear clocks, which could one day guide submarines and deep-space probes without GPS.
The fluorinated borate compound could push laser light to a record 145.2 nanometres (nm) – a wavelength short enough to meet a key requirement for these ultra-precise, portable clocks being developed in the United States, China and elsewhere, the team reported in Advanced Materials in…