China’s “photon catcher” may mark a quantum leap in counter-stealth, but technical limits show the bigger challenge is the conflict between stealth and counter-stealth systems.

This month, the South China Morning Post (SCMP) reported that China has begun mass-producing the world’s first four-channel, ultra-low noise single-photon detector—dubbed the photon catcher—a breakthrough that could significantly advance stealth aircraft detection and quantum communication technologies.

Developed by the Quantum Information Engineering Technology Research Centre in Anhui province, the detector can sense individual photons—the smallest unit of energy—enabling quantum radar to spot stealth jets like the US F-22 Raptor by identifying minute quantum changes that traditional radar cannot detect.

Reported by China’s Science and Technology Daily, the achievement marks self-sufficiency and global leadership in quantum information components, with the device reducing noise by 90% and operating at temperatures as low as -120°C.

Researchers say the detector’s four-channel design allows simultaneous multi-wavelength scanning, improving imaging rates while consuming minimal power—making the radar both harder to detect and more reliable in complex electromagnetic environments.

The technology, now in service with top Chinese institutions, is also expected to underpin next-generation quantum communication networks and applications from biomedical imaging to deep-space laser ranging.

Quantum radar uses entangled photons, sending one toward a target while keeping its twin in reserve. When the returning photon interacts with the stored one, their quantum link confirms detection.

But such futuristic claims warrant closer scrutiny. In a 2022 paper for the Canadian National Defense College, Graham Hill mentions that photon-sensing quantum radar could detect low-reflectivity and stealth targets by correlating entangled photon pairs, improving signal-to-noise ratios by up to six decibels and extending detection range by roughly 40%.

Hill adds that the technology’s low probability of intercept makes it nearly immune to jamming and ideal for penetrating high-noise or cluttered environments.

However, he also states that real-world deployment faces severe technical barriers—notably cryogenic cooling requirements, limited range beyond 10 kilometers and long signal integration times—making it currently impractical for operational use.

Similarly, Heather Penney mentions in a January 2024 paper for the Mitchell Institute for Aerospace Studies that quantum radar faces technical constraints such as decoherence, low photon return rates, and environmental noise, which makes real-world performance unreliable.

Penney says that while the system attracts strategic interest, it remains a laboratory curiosity rather than a deployable capability.

In addition to those points, Edward Parker mentions in an October 2021 RAND report that current prototypes remain laboratory-scale, limited by fragile entanglement and cryogenic requirements. Parker adds that until recently, quantum radars were only capable of tracking the target’s distance from the receiver, but not its direction or speed.

He notes that quantum radars cannot track target direction or speed using the Doppler effect, as conventional radars do. Due to those drawbacks, he states that quantum radar will not provide upgraded capability to the US military, concluding that despite China’s reported advances, it remains a speculative, long-term prospect, not a deployable technology.

Such disadvantages may have influenced the US to pursue alternative short-range detection technologies. For instance, The War Zone (TWZ) reported in January 2025 that the F-22 would receive infrared search-and-track (IRST) systems, a proven passive sensor technology that detects targets in the infrared spectrum regardless of their stealth features, even in a heavy electronic warfare environment.

But even if quantum radar has significant limitations and may still be in the prototype stage, it could significantly bolster a layered sensor network. A quantum radar node, if fielded, would act as an additional source of detection data that stealth aircraft might find hard to evade. The combination of sensors can compensate for each sensor’s gaps, creating a counter-stealth ecosystem.

For instance, space-based optical sensors can be used to detect stealth aircraft. In December 2021, a B-2 bomber was photographed on Google Maps – showing that while stealth aircraft can evade radar and possibly thermal sensors, it is nowhere near invisible in broad daylight.

Showing the potential military application of that concept, Clayton Swope mentions in a January 2024 Center for Strategic and International Studies (CSIS) article that China’s Yaogan-41 satellites, operating in geostationary orbit, offer persistent optical surveillance across the Indo-Pacific.

Swope says that with a resolution potentially as small as 2.5 meters, it can identify car-sized objects, including airborne assets. He adds that, unlike radar, optical sensors are less affected by stealth coatings and shaping. By continuously monitoring airspace, Swope states that Yaogan-41 can detect movement patterns, contrails, or thermal signatures of stealth aircraft.

He adds that when paired with AI algorithms trained to recognize anomalies, China can automate detection and tracking, with this data cuing low-earth orbit (LEO) satellites or other platforms for higher-resolution imaging or targeting, enhancing China’s ability to monitor and respond to aerial threats.

Aside from space-based systems, China has fielded counter-stealth ground radar. For instance, J Michael Dahm mentions in a 2020 Johns Hopkins Applied Physics Laboratory (JHAPL) report that China’s very-high-frequency (VHF) “counter-stealth” radar on Subi Reef, called the Synthetic Impulse and Aperture Radar (SIAR), uses multiple-input, multiple-output (MIMO) techniques and circular, random-height arrays to overcome VHF radar’s traditional limits—poor angular resolution and clutter.

According to Dahm, Chinese researchers claim it can generate 3D tracks of stealth aircraft, potentially cueing surface-to-air missiles. He notes the system’s visibility in satellite imagery, extensive technical literature, and televised promotion suggests it is genuine.

But as with counter-stealth technology, stealth technology is also an ecosystem. In a 2020 paper for the Mitchell Institute for Aerospace Studies, Chris Westwood argues that stealth is an ecosystem integrating sensors, data fusion, and command networks.

According to Westwood, true stealth depends on an open, multi-domain “Combat Cloud” that fuses information from distributed sensors, AI-driven analytics, and advanced datalinks.

He says this network allows forces to manage electromagnetic, cyber and kinetic threats in real time, stressing that stealth’s effectiveness derives from the orchestration of architecture, information, and human-machine teaming, not from radar-evading coatings or airframes alone.

In the emerging duel between stealth and counter-stealth, victory won’t depend on a single radar or aircraft but on which side better combines sensors, data, and decision speed into a true system-of-systems.

China’s quantum “photon catcher” radar may indicate ambition. Still, the real battle is in integration: networks versus networks, ecosystems versus ecosystems, where the winner is the side that sees first, strikes fastest, and stays hidden the longest.