Nonlinear optical materials are those materials whose optical properties depend on the intensity of the incident light. Nonlinear optical properties are also called optical properties under the action of strong light, mainly because these properties are only manifested under the action of strong coherent light like a laser.

Nonlinear optical crystals are one of the important photoelectric information functional materials and an important material basis for optoelectronics technology, especially laser technology. Their degree of development is closely related to the development of laser technology.

Nonlinear optical crystal materials can be used for laser frequency conversion to extend the wavelength of the laser; to modulate the intensity and phase of the laser; to realize the holographic storage of the laser signal, eliminate the self-pumping phase conjugation of the wavefront domain change, and so on.Therefore, nonlinear optical crystals are an indispensable key material in high-tech and modern military technology. All developed countries have placed them in a priority development position and included them as an important strategic measure in their respective high-tech development plans. Attach great importance to and support.

My country is at the international leading level in the research of periodic and quasi-periodic polarization phase matching.Because this kind of quasi-phase matching device can give full play to the nonlinear optical properties of the crystal, and a crystal can simultaneously complete the functions of frequency doubling, and frequency, parametric oscillation, etc.Therefore, such technologies have important applications in optical communications, laser display, air pollution detection, medicine, and national defense. QPM materials and devices are showing their strong vitality.At present, the more important ones are PPLN, PPKTP and PPRTA (“PP” is also one of the “quasi-phase matching” notation).

It is widely used in femtosecond lasers, terahertz generation, metrology, optical frequency combs, biophotonics, ARS microscopy, fluorescence microscopy, DNA sequencing, green lasers, laser projection, seabed surveying, quantum optics, quantum computing, precision navigation systems, defense laser confrontation, trace gas detection, radar, aerospace environmental monitoring, etc.

Nonlinear optical crystal materials are a fairly certain industry closely related to laser, optoelectronics, optical communications and other industries, and are greatly affected by the development and changes of these industries.With the rapid development of the wave of informationization around the world at the end of the last century and the widespread adoption of optoelectronics technology, the market demand for photoelectric functional crystals, especially nonlinear optical crystals, has increased sharply at home and abroad.