Researcher Hu Lili inspects continuous melting of laser neodymium glass

The formation, structure and property evolution mechanism of glass is one of the most challenging mysteries in condensed matter physics.

The global glass industry market is huge, and is expected to exceed $1.5 trillion in 2027. China is the world's largest glass producer (>50%), but many high-end glass products are still controlled by others. For example, a square meter of neodymium glass costs 300,000 yuan. After it is cut, the cut neodymium glass absorbs enough energy to produce dazzling ultra-strong lasers, which can become the "heart" of ultra-strong lasers. After the United States, Germany, Japan and other countries spent six years to complete the research and development of this glass, they strictly blocked and embargoed the relevant preparation process technology, equipment and products.

This is one of the important challenges China faces in developing ultra-intense lasers.

Hu Lili, an academic leader in the field of laser glass in China and a researcher at the Shanghai Institute of Optics and Precision Mechanics of the Chinese Academy of Sciences (SIOM), has made a breakthrough after seven years of hard work and developed neodymium glass for China's "Shenguan".

In January 2025, 62-year-old Hu Lili, with gray hair, stepped onto the podium of the ICG (International Glass Association) President's Award after 38 years of deep cultivation in the glass field. She is the third Chinese scholar to win the award in the 30 years since the award was established. The sentence on the award certificate is touching: glass dream. Before that, she won the NF Mott Award, a famous award aimed at rewarding outstanding scientists who have made outstanding contributions in the field of amorphous materials. She is the first Chinese winner of the award since its establishment in 1983.

Laser Neodymium Glass

Hard work makes the country prosperous. In the past ten years, we have made great efforts to make neodymium glass for China's "Shen Guang".

" Glass is not like crystals , it does not have a regular structure. It is not easy to give glass special properties and develop special glass, and there is a lack of systematic theory." Hu Lili said in an interview with The Paper recently. But in order to meet the major strategic needs of the country, she took the initiative to change the "track".

"Since I started to engage in glass research in 1987, my guiding ideology, including what I tell my students, is that if a material is made, it must be used. The research of materials is ultimately to be applied. Therefore, I am very happy to start from basic research in the laboratory, and finally to pass the preparation process technology and make the product." Hu Lili said this and did so. In the field of special glass and optical fiber research and development, she led the team to continuously innovate.

To meet the urgent need of China's independent research and development of laser fusion devices, Hu Lili has led her team since 2005 to carry out continuous research on the four key core technologies of continuous melting, precision annealing, hemming and testing, covering the development of new high-gain laser neodymium glass and batch preparation of large-size laser neodymium glass, starting from basic research, for nearly ten years.

The most challenging part was the continuous melting technology of large-scale laser neodymium glass. Problems arose one after another, such as excessive hydroxyl and transition metal impurities, glass cracking, and streaks and bubbles inside the glass. The research team tested, analyzed, and discussed solutions again and again.

In 2012, with the joint efforts of everyone, the many difficulties in the continuous melting process were finally overcome. They designed and established a pilot production line for laser neodymium glass continuous melting, and achieved the integration and connection of key technologies in the entire chain.

Study on the technology of neodymium glass edging

So far, the research team has successfully completed the development of large-size laser neodymium glass for the "Shenguang" series of devices. The core technical indicators of the independently developed laser neodymium glass finished product, such as platinum particles and hydroxyl absorption coefficient, are internationally leading, successfully challenging the technical limits that can only be achieved by the United States, Germany and Japan working together.

Neodymium Glass Team

The relevant achievements have successively won the "Shanghai Technological Invention Special Award" in 2016, the "National Technological Invention Second Prize" in 2017, and the "Outstanding Scientific and Technological Achievement Award of the Chinese Academy of Sciences" in 2022.

Eight years of hard work to break the foreign monopoly and embargo

Fiber lasers are lasers that use optical fiber as the laser medium. They are widely used in a wide range of applications, including laser space long-distance communications, military defense security, medical equipment and instruments, large-scale infrastructure, etc. Since the beginning of the 21st century, fiber lasers have gradually occupied half of the laser market.

The core of the 10,000-watt high-power ytterbium-doped large-mode-field optical fiber needs to withstand ultra-high laser power density, which can easily cause color centers, resulting in a drop in output power and destroying the stability of the laser system. Public information shows that color centers refer to zero-dimensional defects in the crystal that cause light absorption or emission.

Fiber Supercontinuum

Ytterbium-doped large mode field fiber is the core gain medium of high-power fiber lasers. Its function is to generate lasers and amplify the laser power to achieve an output power of tens of thousands of watts. However, this fiber product and its preparation process have long been monopolized and strictly controlled by American companies such as Nufern and nLight, becoming a technical bottleneck restricting the development of high-power fiber lasers in China.

Specialty Optical Fiber

Since 2011, researcher Hu Lili has led a young R&D team to focus on three difficult issues of high-power laser fiber, namely laser efficiency, power stability and long-term reliability. After eight years of hard work, they started from the basic research on the structure-performance relationship of rare earth-doped quartz glass, and carried out a series of research work in the core composition design, preparation process optimization and cladding structure innovation of ytterbium-doped laser fiber. They were the first in China to overcome the key technology of mass preparation of 10,000-watt-class ytterbium-doped large-mode-field optical fiber.

Optical fiber preform

This technological breakthrough solved the problem of key components of China's high-power fiber lasers, allowing China's high-power fiber lasers to be equipped with domestic "cores". Several high-performance ytterbium-doped laser fibers developed by the team also broke the product embargo of foreign companies and their technology and product monopoly, meeting the urgent application needs of high-power fiber lasers in space environments. Since 2019, the research team has achieved direct sales of more than 200 million yuan and indirect economic benefits of more than 1.8 billion yuan.

High purity quartz

AI+special glass structure and effect theory research, aiming at the future

Dr. Deng Lu returned from studying abroad and joined the Hu Lili Researcher team. He is currently mainly engaged in material computational simulation and glass structure-activity relationship research. He shared a small incident during the Spring Festival in 2025: At that time, the domestic open source artificial intelligence model deepseek was not as popular as it is now, and some media had just reported on it. Suddenly one day, Researcher Hu Lili posted a report related to deepseek in the work WeChat group, hoping that everyone would pay attention and share her own views.

"She has always been keeping an eye on the cutting edge," said Deng Lu.

With the development of artificial intelligence (AI), the research paradigm of glass needs to be changed urgently. How to achieve the rapid development of new glass materials enabled by AI has become a hot topic. "It will be a tool in the future. We must learn to use this tool well so that our research and development of special glass can be efficient and accurate." Researcher Hu Lili said. Since the "14th Five-Year Plan", she has actively introduced outstanding overseas talents in interdisciplinary fields to create a glass structure-activity relationship research platform covering glass structure performance characterization, molecular dynamics simulation, and AI-assisted modeling. In order to further accelerate the construction of the glass structure-activity relationship platform, Researcher Hu Lili led team members to visit relevant units many times, organize academic forums, and actively plan the demonstration work of related platforms. It is expected that during the "15th Five-Year Plan" period, a special glass material structure-activity relationship platform integrating high-throughput preparation, AI-assisted modeling, and structural characterization verification will be built to innovate the research and development paradigm of special glass.

Specialty Fiber Team