A research team in China has developed the world's first nuclear optical clock, marking a shift in precision measurement from electron transition to thorium-229 nuclear transition. The project, led by Tsinghua University in collaboration with several domestic institutions, spanned nearly five years of development.
The team successfully engineered a 148-nanometer continuous-wave vacuum ultraviolet laser to drive the nuclear transition of thorium-229. By stabilizing the laser frequency on this transition, researchers created a new time-frequency standard that follows traditional atomic microwave and optical clocks.
The nuclear optical clock operates by counting nuclear transitions, achieving a rate of approximately 2 quadrillion counts per second. Because atomic nuclei are significantly smaller than electron clouds, they are less susceptible to external environmental interference, resulting in superior stability.
The researchers highlighted the potential for further miniaturization of this technology. Future applications include enhancing navigation and deep-space exploration, where the device could provide high-precision positioning and distance measurements for satellites and spacecraft.
