Source: Guangdong Academy of Sciences, Institute of Semiconductors, Optoelectronic Technology Center  3^rd Nov 2025

Recently, the Optoelectronics Technology Center of the Institute of Semiconductors, Guangdong Academy of Sciences, has made significant progress in the preparation of laser crystal materials. Using a resistance furnace, it has successfully grown larger-sized Ce,Nd:YAG crystals, increasing the crystal diameter from the previous 40 mm to approximately 60 mm, with the crystal exhibiting uniform and stable optical properties.

YAG crystal: The "heart" of the laser

YAG crystals, particularly neodymium-doped (Nd:YAG) and cerium-neodymium co-doped (Ce,Nd:YAG) variants, can be regarded as the "heart" of many laser devices. They generate high-quality, high-power lasers, finding extensive applications in key national sectors such as optical communications, medical equipment, precision measurement, mechanical processing, and radar—playing a vital role in both our daily lives and cutting-edge technology.

Traditional Growth Methods: High Quality but High Cost

In the past, high-quality YAG crystals were mostly grown using induction furnace methods. While this approach yields crystals with excellent optical performance, it has significant drawbacks: it requires expensive iridium crucibles, and growing a single crystal takes over 30 days, resulting in extremely high production costs.

Resistance Furnace Method: Great Potential but Bottlenecks

In contrast, crystal growth using resistance furnaces shortens the cycle to around 7 days and reduces costs. However, due to slow technological development and external technological blockades, this process has long faced a bottleneck—the diameter of grown crystals has mostly remained around 40 millimeters. Smaller sizes mean fewer usable components per crystal and low material utilization, which has largely restricted its industrial application.

New Breakthrough: Larger, More Uniform, and More Efficient

To address this challenge, the research team at the Optoelectronics Technology Center, through dedicated research, comprehensively optimized and innovated everything from raw material ratios and temperature field structures to growth processes. They successfully increased the diameter of Ce,Nd:YAG crystals grown via resistance furnaces to approximately 60 millimeters, achieving a new breakthrough in crystal size under this domestic technical route.

This technological breakthrough has provided solid support for the large-scale industrialization of high-performance laser crystals and laid a technological foundation for the subsequent research and development of multi-functional doped crystals. This progress has not only broken the long-term size bottleneck that constrained the development of the resistance furnace method but also redefined the balance between crystal growth efficiency and cost control.