The research on nonlinear crystals started late. However, at present we have basically mastered almost all laser pointer crystal growth techniques. And some non-linear photonic crystal materials have become an important strategic material of the country. Obtain national protection and support. To give an example, the KBBF nonlinear crystal invented in our country is very original and has great influence at home and abroad. KBBF crystal is a kind of deep ultraviolet non-linear crystal, it can produce 176 nanometer wavelength laser, this is the world's first kind of crystal that can produce deep ultraviolet laser, its strategic significance is self-evident. Because of its importance, our country has banned the export of KBBF nonlinear crystals to Japan, Europe and the United States. Therefore, China has reached world-class level in some respects. And the main product of crystal color white series photonic wafers also belong to nonlinear crystal materials. Combining quasi-phase matching theory, from nonlinear photonic crystal to white light laser was born. Experienced a long road of research.
Can a laser emit a green laser pointer like sunlight? Covers infrared, visible light, ultraviolet and other spectrum bands. Now, the idea of flying through the sky has been realized. After nearly 20 years of accumulation and unremitting research, Li Zhiyuan's research team has invented the white series of photonic chips. The wafer allows the laser to produce white light lasers including infrared, visible, and ultraviolet. This technical achievement won the "2015 China Optical Important Achievement Award.