On September 15th, according to a report on Nanjing University’s WeChat public account, on the night of the 14th, the world’s top academic journal “Nature” published a major breakthrough in the field of next-generation optoelectronic chip manufacturing by the research team led by Zhang Yong, Xiao Min, and Zhu Shining from Nanjing University!

The scientific research team invented a new "non-reciprocal femtosecond laser polarized ferroelectric domain" technology, which focuses the femtosecond pulsed laser on the inside of the crystal of the material "lithium niobate", and controls the direction of the laser movement to form inside the crystal. Effective electric field enables direct writing and erasing of three-dimensional structures.

This new technology breaks the light diffraction limit of traditional femtosecond lasers, and reduces the size of the three-dimensional structure of light-engraved lithium niobate from the traditional 1 micron order (equivalent to one-fifth of the hair) to Nano-level, up to 30 nanometers, greatly improves the processing accuracy.

This major invention may open up a new track for optoelectronic chip manufacturing in the future, and is expected to be used in the fabrication of key optoelectronic device chips such as optoelectronic modulators, acoustic filters, and non-volatile ferroelectric memories. Intelligence and other fields have broad application prospects.

This work organically combines femtosecond laser polarization technology with lithium niobate ferroelectric domain engineering, breaking through the barriers of traditional technology and realizing the controllable preparation of nano-ferroelectric domains in three-dimensional space for the first time. Applying it to the field of quantum optics can achieve efficient, high-dimensional and narrow linewidth quantum entanglement generation; in the field of electronics, it can promote the development of high-performance ferroelectric domain wall nanoelectronic devices, such as large-capacity rewritable non-volatile Memory; in the field of acoustics, nano-periodic ferroelectric domain structures can realize ultra-high frequency acoustic resonators and filters. Femtosecond laser polarization technology can be further applied to other ferroelectric crystals, including lithium tantalate and potassium titanium phosphate crystals, etc., and promote the development of high-performance three-dimensional optical, acoustic, and electrical integrated devices.

Source：Nanjing University’s WeChat public