Core Insights - Tsinghua University has achieved a significant breakthrough in the development of nuclear optical clocks by overcoming the last core bottleneck related to continuous wave vacuum ultraviolet light sources [1] - The research team successfully developed a 148-nanometer continuous wave ultra-narrow linewidth laser source, marking the first extension of ultra-stable laser technology into the vacuum ultraviolet band [1] - This advancement addresses a critical technical shortcoming of nuclear optical clocks, paving the way for new developments in precision measurement and showcasing China's leading capabilities in quantum technology and fundamental research [1] Technical Breakthrough - The research team innovatively proposed a new scheme using metal vapor four-wave mixing, breaking away from the mainstream nonlinear crystal approach [1] - This innovation achieved continuous wave output at 148 nanometers and reduced the linewidth by nearly six orders of magnitude, laying the foundation for ultra-stable laser technology in the vacuum ultraviolet band [1] - The team has completed a key technological breakthrough ahead of international counterparts in similar research areas [1] Application Value - The results have significant application value, supporting not only nuclear optical clock research but also serving as a general platform for atomic optical clocks, quantum information, and condensed matter spectroscopy [2] - Potential applications include autonomous navigation, deep space exploration, high-precision geological and gravitational detection, and the realization of semiconductor vacuum ultraviolet measurement and high-end testing equipment that is self-controlled [2]