Lithium niobate is famous for its electro-optical properties and has become one of the most widely used optical materials. Lithium niobate modulators are the backbone of modern telecommunications, converting electronic data into optical information at the end of optical cables. However, it is very difficult to manufacture high-quality devices on a small scale using lithium niobate, which makes it impossible to realize integrated chip applications.

A few days ago, researchers at Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a technology that uses lithium niobate to fabricate high-performance optical microstructures, which opens the way to ultra-efficient integrated photonic circuits and quantum photonics. The door to the fields of science and microwave-optical conversion.

This research uses traditional micro-manufacturing processes to produce high-quality lithium niobate devices with ultra-low loss and high optical confinement. Loncar laboratory uses standard plasma etching to engrave microresonators on lithium niobate films based on its expertise in the diamond field, and proves that nanowaveguides can propagate light on a one-meter optical path with only about half the optical power loss. Under the same conditions, the light propagated in the previous lithium niobate devices will lose at least 99%. Since the propagation loss per meter of the nanowaveguide is less than 3dB, scientists can perform complex manipulation of light over a path length of 1 meter. In addition, these waveguides can be bent, so a one-meter-long waveguide can be packed in a one-centimeter-sized chip.

This achievement is a major breakthrough in integrated photonics and lithium niobate photonics, which will make various optoelectronic functions possible, and means that lithium niobate will solve the key application problems of data center optical links. Lithium Niobate Film (TFLN) is very suitable for any function that needs to modulate light or change the frequency of light. In the next few years, TFLN will provide optical modules for data centers to achieve functions similar to today's telecommunications equipment, but with smaller size, lower cost, and lower power consumption.

The researchers' next goal is to develop a lithium niobate platform based on the results, which can be applied to a series of fields such as optical communications, quantum computing and communications, and microwave photonics.