On August 12, the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, announced that a team led by Researchers Li Gang and Jin Yuqi from the Institute's Chemical Laser Research Center (Group 700), in collaboration with a team led by Researcher Wang Feng from the Institute's Bioenergy Chemicals Research Group (Group DNL0603), has made new progress in the research of ultra-high reflectivity laser mirrors. They have developed a quartz laser mirror with a reflectivity exceeding 99.999% in the near-infrared band.
Laser mirrors are key components for transmitting and controlling laser beams in high-energy laser systems. As high-energy laser output power continues to increase, the demand for laser mirror performance indicators, such as reflectivity and absorption loss, is also increasing to further reduce thermally induced deformation and improve laser beam quality. Scattering loss caused by the surface roughness of optical components and absorption loss in optical thin films are the main factors limiting reflectivity improvements.
Preliminary work by the research team has identified key factors influencing quartz component surface roughness, submicron-sized surface defects, and surface impurities. Building on this, the research team used their proprietary ultrafine nano-cerium oxide polishing slurry to surface-process the quartz components. Ultimately, using the cavity ring-down method, they measured the quartz mirror's reflectivity at a wavelength of 1064nm to be 99.99934%. The ultra-high-reflectivity laser mirrors developed in this work could provide technical support for improving the performance of high-energy laser systems and have potential applications in gravitational wave detection and space laser communications.
