The push towards smaller, more powerful optical devices faces a hurdle, especially in the infrared (IR) spectrum. While conventional lenses and components are often bulky and single-function, the IR range which is vital for sensing, imaging, and communications lacks diverse, compact beam-shaping tools.

Metasurfaces, ultra-thin structured films, offer a solution, enabling light manipulation on an unprecedented scale. However, their creation has traditionally been slow and complex.

A Simpler Path with Direct Laser Writing

A different approach is changing the game: Direct Laser Writing (DLW). Recent research confirms that DLW offers a “simple and convenient alternative” and holds “great potential for speeding up the fabrication and enabling rapid prototyping”. Instead of intricate, multi-step lithography, DLW uses a focused laser beam to directly pattern optical elements.

This method shines when paired with phase-change materials (PCMs) like In3SbTe2 (IST). IST can be locally switched from an insulating to a metallic state using laser pulses. By ‘drawing’ tiny metallic antennas and precisely controlling their orientation, DLW can create metasurfaces that use the ‘geometric phase’ to sculpt light. This allows complex functions like beam steering, lensing, holography, and even the generation of exotic vortex beams to be programmed directly onto the surface.

Enabling On-Demand Metasurfaces

The significance? DLW makes fabricating large-area, functional metasurfaces “much simpler, cost-effective, and faster compared to cumbersome fabrication techniques such as conventional lithography” involving multiple time-consuming mask designs and costly etching steps. The demonstrated ability to fabricate complex, millimeter-scale metasurfaces containing millions of individual antennas in just a few hours highlights the power of direct writing for rapid prototyping.

This isn’t just about speed; it’s about flexibility. DLW allows for:

• Rapid testing: Quickly iterating through different designs.
• Customization: Creating tailored optics for specific IR applications.
• Multi-functionality: Combining several optical tasks onto a single, flat surface.

As a leader in high-precision laser lithography, Heidelberg Instruments sees direct writing as a key enabler for the next generation of optical technology. It’s paving the way towards readily available, custom-designed meta-optics, unlocking new possibilities in the crucial infrared spectrum and beyond.

Explore how Heidelberg Instruments empowers next-gen optics with Direct Laser Writing. Get in touch to discuss your application.