China's 60-Millimeter BGSe Crystal Opens a New Chapter in Anti-Satellite Laser Development

A small crystal with major stakes in space

Chinese scientists have developed what is described as the world's largest barium gallium selenide crystal, measuring 60 millimeters in diameter and capable of withstanding laser intensities of up to 550 megawatts per square centimeter. The material, known as BGSe, could support more powerful laser systems intended to blind or disable satellites.

Professor Wu Haixin and his team at the Hefei Institutes of Physical Science, under the Chinese Academy of Sciences, led the development. Their achievement addresses a practical problem in building powerful lasers: the components handling the beam can suffer damage before the system delivers its intended effect.

As of August 9, 2025, the development sits at the intersection of materials research and military competition. Larger, more durable crystals could support infrared sensing, medical diagnostics and scientific instruments. They could also help China develop weapons aimed at satellites that provide intelligence, navigation, communications and warnings of missile launches.

The strategic concern reaches beyond the United States to India and other nations with growing interests in space. Modern armed forces depend on satellites to see distant activity and coordinate operations. Disrupting those services could leave commanders with less information at precisely the moment they need it most.

The crystal's role is to change the wavelength of laser light. Its appeal comes from combining that ability with resistance to intense energy. Turning those properties into a weapon also involves the larger system: a laser source, optics and the ability to direct a beam toward a moving target. The development account gives no date for deploying a weapon incorporating the new crystal.

Why BGSe matters to powerful infrared lasers

BGSe converts short-wave infrared laser light into light in the mid- and far-infrared ranges. Wavelength describes the spacing of a light wave; changing it changes how the light interacts with materials and the atmosphere. The attraction for lasers aimed from the ground toward space is the ability of suitable infrared wavelengths to travel through the atmosphere with relatively little loss.

The newly developed crystal can reportedly tolerate laser intensities up to 550 megawatts per square centimeter, described as ten times the threshold of current crystals intended for military use. That figure measures the intensity falling on a particular area of material. The practical benefit is greater tolerance of the energy passing through the crystal.

Damage to a laser's own components has long complicated efforts to increase power. The historical comparison cited in the development account is the US Navy's MIRACL test in 1997, when powerful lasers were described as melting their own components during trials against satellites. A more resilient crystal offers a route toward systems that can operate at greater power with better stability and longer reach.

BGSe's wavelength conversion and resistance to damage serve different purposes. Conversion produces the desired infrared light; durability helps the component survive the process. Together, those properties explain why increasing both the size and quality of the crystal attracts interest from researchers and military planners.

How the crystal is made

Wu's team uses highly pure barium, gallium and selenium, sealed under vacuum in quartz tubes. The production account describes zone refining at temperatures above 1,000 degrees Celsius, followed by slow crystal growth over about a month.

Annealing and polishing come afterward. Annealing is a controlled heat treatment used to reduce defects, while polishing prepares the optical surfaces through which light passes. The objective is a crystal with the clarity and consistency needed to handle an intense laser beam.

Oxygen or moisture contamination can ruin a batch even in small amounts. That sensitivity makes production demanding and helps explain why achieving a larger usable crystal is more complicated than simply increasing the quantity of raw material. The manufacturing challenge has also made the process difficult to reproduce outside China.

From a 2010 discovery to a larger crystal

Chinese researchers first discovered BGSe in 2010. Its optical properties soon attracted international attention, but producing larger crystals with sufficiently few defects remained difficult. Western defense companies have struggled to reproduce the size and quality achieved by Wu's team, and the largest BGSe crystal previously reported was described as much smaller.

The University of Michigan's ZEUS laser provides a comparison in the wider field of powerful laser materials. It uses a crystal of titanium-doped sapphire nearly 18 centimeters wide, which took more than four years to produce. That crystal is larger than the new BGSe specimen, but it serves a different optical purpose and is not optimized for the same infrared wavelengths.

China's achievement concerns the scale and quality of BGSe specifically, along with the ability to produce it relatively quickly. Different laser materials handle different wavelengths and perform different jobs, so size alone gives only part of the picture.

The development spans several stages:

• 1997: The US Navy's MIRACL trials illustrated the problem of laser systems damaging their own components.
• 2010: Chinese researchers first discovered BGSe.
• Since 2020: BGSe crystals have been incorporated into various research and development projects.
• April 2025: General Bradley Saltzman addressed the threat from Chinese lasers in testimony before the US-China Economic and Security Review Commission.
• August 9, 2025: The account of Wu's team's 60-millimeter crystal placed the development within the wider debate over satellite security.

Why satellites are central to the military stakes

China's interest in directed-energy weapons, including lasers on the ground, reflects the military value of space services. Intelligence, surveillance and reconnaissance, often shortened to ISR, help armed forces identify activity and follow threats. Other satellites provide navigation and communications, allowing units separated by large distances to coordinate.

Chinese military thinking describes approaches called systems confrontation and systems destruction warfare. In plain language, the aim is to weaken an opponent by disrupting the key connections and services that allow its forces to function together. Satellites are valuable targets because so many operations depend on them.

Lasers offer the prospect of disrupting those services in ways that can be scaled, potentially cost less than some alternatives and be difficult to attribute. A temporary interruption could create confusion during a crisis, while lasting damage could remove a satellite's capabilities for much longer. China seeks an advantage through such disruption while limiting the risk of overt escalation.

General Bradley Saltzman, Chief of Space Operations for the US Space Force, described the purpose of China's lasers on the ground in terms of their effects on American military information gathering:

blind and deafen US forces by targeting critical space-based ISR assets.

During his April 2025 testimony before the US-China Economic and Security Review Commission, Saltzman also warned that such systems could have a wider operational effect:

leave the US military blind and deaf

The United States depends on hundreds of satellites for global surveillance, navigation and communication. That reach is a military strength, but it also gives an adversary a set of valuable services to disrupt.

Xinjiang facilities and the challenge of higher orbits

Satellite imagery and intelligence accounts have identified facilities at Korla and Bohu in Xinjiang associated with large laser systems on the ground. The installations are believed to be operational and capable of temporarily dazzling satellites or causing permanent damage.

Dazzling means temporarily overwhelming a satellite's optical sensor so that it cannot collect a useful image. Permanent damage is a more lasting outcome. The difference matters to military planners because a temporary loss of observation and the destruction of a sensor create different problems for the satellite operator.

Current systems are described as most effective against satellites in Low Earth Orbit, or LEO, where many American and allied ISR spacecraft operate. Chinese research and military writings also point to ambitions to reach Medium Earth Orbit, or MEO, and Geosynchronous Earth Orbit, or GEO.

The US Global Positioning System, or GPS, and the Space-Based Infrared System, or SBIRS, are identified as particularly sensitive assets in that discussion. GPS supports navigation, while SBIRS helps detect missile launches, including threats relevant to nuclear warning. Extending effective engagement to these higher orbital regions would widen the set of military services at risk.

An attack on SBIRS would carry especially serious escalation risks because of its role in warning of nuclear missile launches. The threat to such a system can influence decisions during a crisis even before a weapon is used.

Large satellite networks complicate an attack

Starlink illustrates another challenge for efforts to disable services from space. Modern constellations can contain hundreds or thousands of small satellites, spreading a network's work across many spacecraft. Removing one satellite may have little effect on the service as a whole.

Chinese analysts acknowledge that disrupting such a network would require coordinated action against many targets. Their proposed response combines several methods rather than relying on a laser alone:

• Electronic warfare, including jamming signals or spoofing them with misleading information.
• Cyberattacks aimed at satellite control systems.
• Directed-energy weapons, including lasers and microwave systems.

The intended approach is adaptable and asymmetric, meaning it seeks ways to exploit an opponent's dependencies without matching every part of its military capability. Difficulty identifying the attacker also makes these methods attractive for conflict in the grey zone, where hostile actions take place below the level of openly declared war.

Uses beyond weapons

Chinese scientists also point to civilian uses for larger BGSe crystals. Their ability to produce infrared light could support advanced imaging for medical diagnostics and highly sensitive detectors for scientific research.

Other applications include infrared sensors for tracking missiles and identifying aircraft. Those examples show how the same material can serve both scientific and military purposes, depending on the equipment in which it is installed.

BGSe crystals have been used in various research and development projects since 2020. Increasing their size and reducing defects could broaden the work possible with them, while the demands of manufacturing remain central to whether production can expand.

The range of uses complicates efforts to monitor the technology's spread. A crystal intended for a research instrument and one intended for a military system draw on the same underlying optical properties. Regulation therefore has to contend with a material that has legitimate civilian value as well as potential military applications.

How the United States and regional powers are responding

The United States views the development as a challenge to its longstanding position in space. The Pentagon is reassessing its approach to deterrence, with calls for greater investment in satellite resilience, rapid replacement of lost capabilities and offensive countermeasures.

Resilience means keeping services available even when part of a system is disrupted. Rapid reconstitution means restoring a lost capability quickly, including by launching replacement satellites. Both approaches aim to reduce the benefit an attacker might gain from striking first.

India and other regional powers are watching China's progress as they consider their own countermeasures and directed-energy capabilities. Indian coverage has placed the development within concerns about China's growing assertiveness in space and on Earth.

European commentary has also focused on the potential changes to lasers and infrared sensing. The Visegrád Post used the description "satellite-killing weapon", while European assessments described the technology's potential to "revolutionize long-range laser systems and infrared sensing technologies".

The concern extends beyond the crystal itself to competition among countries seeking ways to attack satellites and protect their own. Its civilian applications make monitoring and regulation more complicated, while the military interest adds pressure to develop countermeasures.

Speed, uncertainty and the risk of escalation

Directed-energy weapons appeal to military planners because their beams travel at the speed of light, giving a target no warning or time to react to the beam itself. They can also keep operating while sufficient power is available, offering the prospect of repeated engagements without the same ammunition limits as missiles.

Lasers can be used at different levels, from temporary dazzling to permanent damage. Difficulty attributing an attack may give the operator room to deny responsibility. These features could make them useful during a confrontation, but they also create uncertainty for the country whose satellites lose capability.

Space security concerns described in the development account include the view that attacking satellites can be easier than defending them. That imbalance can encourage pressure to strike first. Weak international norms and the lack of binding arms control agreements covering these threats add to the difficulty of managing escalation.

Analysts warn against relying too heavily on resilient satellites and ambiguous signals of intent to deter attacks. The measures advocated include satellites that are harder to damage and able to maneuver, rapid launch and replacement capabilities, offensive options, and international cooperation on arms control.

An analyst whose name was not given in the August 9 account described the development as a warning about the direction of competition:

The unveiling of China's BGSe crystal is not just a technical achievement—it is a signal that the space domain is entering a new era of competition, where technological surprise could decide the outcome of future conflicts.

For military operators, the concrete stakes are continuity of navigation, communications, surveillance and missile warning. For researchers, the achievement is a larger infrared optical material that can withstand intense laser energy. Those two interests now meet in the same 60-millimeter crystal.

Key Points

• Professor Wu Haixin's team developed a BGSe crystal measuring 60 millimeters in diameter, described as the world's largest of its kind.
• The crystal reportedly tolerates up to 550 megawatts per square centimeter, ten times the stated threshold of current military crystals.
• BGSe converts short-wave infrared light into mid- and far-infrared light, with applications in lasers, sensing, medical diagnostics and research.
• Facilities at Korla and Bohu in Xinjiang are believed to support Chinese lasers intended to dazzle or damage satellites.
• China's ambitions include reaching higher orbits, while large satellite constellations complicate efforts to disable entire networks.
• US concerns focus on protecting surveillance, navigation, communications and missile warning through resilience, replacement capabilities and deterrence.