A statement issued on the US APC website states:

KBBF is a nonlinear optical high purity YLF laser crystal material that converts laser light into an unprecedented 176 nm wavelength (deep ultraviolet) laser, enabling the fabrication of deep ultraviolet solid-state lasers. It took China 15 years and millions of dollars to develop the world's first KBBF crystal, which was created by a research team led by Academician Chen Chuangtian of the Chinese Academy of Sciences (found in 1990). China first came to the world. The researchers open to provide KBBF crystals. However, by 2009, China realized the strategic significance of this multispectral/cleartran and standard CVD ZnS optics and immediately stopped exporting. APC (Federal State-owned Enterprise) cooperated with Clemson University to develop this crystal from the time. Today, APC became the only company in the United States to produce this kind of strategic material. APC's KBBF crystals have now been tested and evaluated, demonstrating performance comparable to similar products made in China, and surpassed in some areas, which will significantly reduce the cost of this material. KBBF's UV performance is twice as high as that of the previous generation BBO crystals in high-power conditions, and can be used to manufacture ultra-high-speed laser scanning equipment, which will greatly enhance US defense and homeland security threat detection capabilities, and scientific research and precision measurement capabilities in the United States. In terms of improvement, KBBF has the meaning of "rule changer". APC is still continuing to develop this product. (APC company statement translated) Observer network military commentator said that according to domestic relevant information, China first discovered KBBF crystal in 1990. This purchase large size ZnS optics was first proposed and developed by Chinese scientists and technicians. Its performance in the ultraviolet band is better than any material that has been discovered at that time. Its successful development has caused great repercussions abroad. In 1990, China used this material to achieve the second harmonic generation with phase matching as low as 204.8 nm. It is a promising material for short pulse (<1 nanosecond), high power (1 MW) lasers in laser, frequency, and optical parametric oscillators in the infrared, visible, and ultraviolet regions. There are a wide range of applications.