Researchers at KAIST and POSTECH have developed a new nanofabrication technique that lets them 3D print vertical nanolasers directly onto semiconductor chips.
They pulled this off by combining electrohydrodynamic printing with tight control over crystallization. This approach finally breaks through some stubborn limits in laser miniaturization, and it could shake up dense photonic integration, secure optical devices, and whatever comes next in computing tech.
Reimagining Nanolaser Fabrication
For years, integrating nanoscale lasers onto chips mostly meant using complicated, subtractive lithography. These old-school methods are expensive, not very flexible, and just can’t hit the precision mark for real 3D structures.
The KAIST and POSTECH team took a different path. Instead of carving out shapes, they decided to build them up right where they’re needed.
The core of their method is an ultra-fine electrohydrodynamic (EHD) 3D printer that dispenses attoliter-scale droplets. Those volumes are so tiny it’s tough to even imagine.
They use electrical voltage to control droplet ejection, letting them form pillar-shaped nanostructures thinner than a strand of hair.
Why Vertical Nanolasers Matter
Most on-chip lasers sit horizontally, hogging chip space and leaking light into the substrate. Vertical nanolasers, though, stack up instead of spreading out.
This change slashes the footprint and boosts optical confinement, which is a big win for densely packed photonic systems.
Perovskites and Near-Single-Crystal Quality
The researchers picked perovskite materials for their stellar optical properties—strong light emission and tunability. But perovskites can be tricky, since they’re sensitive to how you make them.
Surface roughness and crystal defects usually mean more optical loss. To get around this, the team paired EHD printing with gas-phase crystallization control.
This combo gave them perovskite nanostructures with really smooth surfaces and nearly single-crystal quality. That makes the lasers way more efficient and effective.
Precision Through Height Control
Maybe the most interesting part is how easily they can tune the wavelength. Instead of swapping out materials, they just change the height of the printed pillar to adjust each nanolaser’s emission wavelength.
That kind of flexibility is a big deal for anyone designing photonic circuits.
Advantages Over Conventional Lithography
This method beats lithography-based fabrication when it comes to both device density and adaptability. You can place structures exactly where you want, reshape them, or redesign without going through expensive, time-consuming steps again.
Some of the standout perks:
Invisible Security Patterns
To show off what the tech can do, the team made laser-based security patterns invisible to the naked eye but readable with special optical gear.
That’s a tempting feature for anti-counterfeiting and authentication—security elements that stay hidden and are tough to copy.
Implications for Future Technologies
The possibilities go way beyond security. Vertically integrated nanolasers could become a cornerstone of ultra-high-speed optical computing, where light takes over from electrons for data processing.
That could mean faster speeds and less heat. Other promising directions include:
Research Leadership and Support
This project came together under the leadership of Professors Ji Tae Kim at KAIST and Junsuk Rho at POSTECH. Dr. Shiqi Hu took the role of first author.
The team published their findings in ACS Nano on December 6, 2025. South Korea’s Ministry of Science and ICT backed the research through several programs that encourage young and mid-career scientists, plus some initiatives focused on weaving AI into design and manufacturing.
Here is the source article for this story: KAIST Researchers Develop Direct Printing of Nanolasers for Optical Computing and Quantum Security​