A deep ultraviolet (DUV) solid-state laser device, invented by the Chinese Academy of Sciences (CAS), has recently passed testing, making China the only country in possession of such technology.

"This is a successful example of China independently developing a sophisticated instrument," said the panel which acknowledged the achievement on September 6.

CAS President Bai Chunli said the success embodies the academy's "dedication to major innovation and breakthrough in seeking development." The use of potassium beryllium fluoroborate (KBBF) once bottlenecked the project. KBBF is a non-linear optical crystal that can transform laser light into DUV for use in solid state lasers. Nonetheless, China lacked the proper technology or equipment to cut it into sophisticated prisms.

Chen Chuangtian, a CAS member, joined hands with Xu Zuyuan, a member of the Chinese Academy of Engineering, and turned to the Hong Kong University of Science and Technology for help.

"We were allowed to use their labs because Chinese mainland research institutes did not have similar ones at that time," Xu said, adding that they eventually, after many strenuous efforts, invented a KBBF prism coupling device.

The device marks the world's first-ever output of 1,064-nanometer's 6-harmonic frequency multiplication, shortening the diode-pumped solid-state laser (DPL)'s wavelength to 177.3nm.

Based on the achievement, the pair later managed to develop an applicable DUV-DPL.

A DUV wave refers to the light wave whose wavelength is shorter than 200nm. Synchrotron radiation and gas discharge are among the main non-coherent light sources to produce DUV lasers. A KBBF prism coupling device-based DPL source features a smaller size, higher energy resolution and higher photon influx density. (China.org.cn)