Researchers at POSTECH have pulled off a breakthrough in nanoscale photonics. They’ve come up with a new 3D printing method for making ultra-compact vertical nanolasers.
By mixing precision electrohydrodynamic printing with advanced crystallization control, the team is opening new doors for high-density optical integration. This could shake up fields like optical computing, quantum communication, and next-gen display tech.
Overcoming the Limits of Conventional Nanofabrication
For decades, the semiconductor and photonics industries have leaned on conventional lithography to make nanoscale devices. Sure, these methods work, but they’re complex, expensive, and restrictive—especially when you want three-dimensional shapes or need to place optical components flexibly on a chip.
Vertical nanolasers are a particular headache. Their performance really hinges on getting the geometry right, keeping surfaces smooth, and minimizing optical loss into the substrate. Subtractive manufacturing just struggles to tick all those boxes.
A New Paradigm: Ultra-Fine Electrohydrodynamic 3D Printing
Professors Ji Tae Kim and Junsuk Rho at POSTECH have rolled out an additive alternative: ultra-fine electrohydrodynamic (EHD) 3D printing. Instead of cutting away material, this approach uses electrical voltage to shoot out and place attoliter-scale droplets of perovskite ink with wild precision.
With this, they can print vertical, pillar-shaped nanostructures that are much thinner than a human hair. That means dense, on-chip integration without the old limitations of lithography.
Engineering Crystal Quality at the Nanoscale
Printing’s only half the battle. At these tiny scales, things like surface roughness and grain boundaries cause optical losses and mess with crystal quality.
To get around this, the team combined their EHD printing with gas-phase crystallization control. This technique carefully guides how the perovskite material solidifies after it’s printed.
Smoother Structures, Higher Laser Efficiency
The payoff? An extremely smooth, nearly single-crystalline perovskite nanostructure. That smoothness slashes light leakage into the substrate—one of the big efficiency killers for vertical nanolasers.
The nanolasers run stably with minimal loss, which is a huge leap for nanoscale laser performance.
Precise Color Control Through Geometry
This tech stands out for its tunability. By tweaking the height of the printed nanostructures, the team can dial in the wavelength—and the color—of the laser light.
That kind of control is crucial for any application needing lots of tightly packed light sources, each working at different wavelengths on the same chip.
Demonstrated Applications: Security and Beyond
To show what’s possible, the researchers made laser security patterns that you can’t see with the naked eye but can pick up with special optical gear. These patterns point to some neat uses for vertical nanolasers, like:
Implications for Optical Computing and Quantum Communication
Directly integrating vertical nanolasers onto chips could really shake things up. Optical computing needs compact, efficient light sources, and this tech might push commercialization forward faster than expected.
Plus, these nanolasers offer precise control and stability, which makes them a strong fit for quantum-secure communication systems. Reliability and scalability matter a lot there, and this approach looks promising.
Looking Ahead: From AR Displays to Optical AI Hardware
The authors, including first author Shiqi Hu, say this approach tackles some big limitations in current semiconductor manufacturing.
They see potential for future applications like:
This work, published in ACS Nano, marks a milestone in nanoscale photonics.
It shows how fresh manufacturing techniques might reshape the future of integrated optical tech—pretty exciting stuff if you ask me.
Here is the source article for this story: Direct 3D printing of nanolasers can boost optical computing and quantum security