On February 12, Tsinghua News Network reported that the research team, headed by Ding Shiqian, an associate professor from the Department of Physics at Tsinghua University, has achieved a remarkable breakthrough in the realm of continuous-wave vacuum ultraviolet light sources. They have successfully developed a 148nm continuous-wave ultra-narrow linewidth laser light source. This milestone represents the inaugural extension of ultra-stable laser technology into the vacuum ultraviolet spectrum, effectively overcoming the final significant hurdle in the advancement of nuclear optical clocks. The newly developed light source boasts an output power surpassing 100nW within the target band, coupled with a linewidth substantially narrower than 100Hz. Moreover, it offers continuous tunability across the 140 to 175nm range. When compared to existing single-frequency vacuum ultraviolet light sources, its linewidth has been diminished by nearly a millionfold, fulfilling the stringent demands for the development of thorium-229 nuclear optical clocks and the quantum coherent manipulation of nuclear transitions.