A Laser on a Chip Can Sketch The Mona Lisa — And Could Power Future LiDAR And Quantum Devices

Insider Brief

• Researchers developed a tiny photonic device called a “ski-jump” that can project and rapidly scan laser beams directly from a chip into free space, potentially enabling faster optical systems for computing, sensing and displays.
• The team demonstrated the technology by projecting images—including a sketch of the Mona Lisa—using a nanoscale waveguide that physically bends upward from a photonic chip.
• The approach could help solve a longstanding engineering challenge in photonics: efficiently linking optical processors on chips with the outside world.

A tiny photonic device that launches laser beams directly from a chip into open space could help bridge a long-standing gap between optical processors and the real world. It might also give Leonardo da Vinci an artistic run for his money.

To demonstrate the idea, researchers used the device to project images — including a recognizable sketch of da Vinci’s Mona Lisa — by sweeping a beam of light across a surface thousands of times per second.

The study, published in Nature, describes what the researchers call a “photonic ski-jump,” a microscopic waveguide that bends upward from a chip and acts like a miniature scanning laser. According to the study, the device can steer light far faster than conventional beam-scanning systems while occupying a footprint smaller than a grain of sand.

Besides the possibility of creating a very tiny Louvre, this advance also means a computer chip could project and steer laser beams directly into the real world — very quickly and from extremely small hardware — enabling compact systems for all sorts of new technologies, from augmented-reality displays to quantum devices.

The scientists — including researchers from MITRE, MIT and Sandia National Laboratories — report the advance addresses a problem that has quietly limited many optical technologies. Photonic chips can manipulate light with high precision inside microscopic waveguides etched into silicon. But sending those signals into open space — where they can illuminate objects, transmit data or control quantum systems — has proven difficult to do efficiently.

The ski-jump device provides a direct pathway from chip to free space.

Researchers describe the device as a nanoscale optical waveguide mounted on a tiny cantilever made from piezoelectric materials — substances that bend when voltage is applied. Internal stresses in the layered structure cause the cantilever to curl upward by roughly 90 degrees, giving the device its “ski-jump” shape.

When electrical signals drive the cantilever into vibration, the tip of the structure moves rapidly back and forth, sweeping a laser beam across space.

The study reports that the device can scan beams at rates exceeding tens of millions of resolvable beam spots per second per square millimeter of chip area, more than 50 times the performance of some mature micro-electromechanical mirror systems used in optical scanning.

Using this motion, the researchers produced images by tracing patterns with light. In laboratory demonstrations, the system projected letters, logos and images — including the Mona Lisa — by rapidly scanning a laser beam across a surface while modulating its brightness.

The experiments illustrate a broader concept: converting light signals traveling through a chip into patterns that exist in the physical world.

Bridging Chips and the Physical World

Modern photonic integrated circuits route light through microscopic waveguides much the way electronic chips route electricity through wires. These systems are increasingly used for communications, sensing and emerging forms of computing.

But the number of optical signals that can leave a chip has been limited by the geometry of waveguides and optical components. In most cases, light exits only from the edge of a chip or through specialized couplers.

According to the study, the photonic ski-jump allows beams to emerge directly from the surface of the chip and scan across space.

That capability could be useful for a wide range of technologies. The researchers point to potential applications in LiDAR systems used in autonomous vehicles, augmented-reality displays, biomedical imaging and optical communication systems.

The approach may also benefit quantum technologies. Many experimental quantum computers rely on precisely targeted laser beams to control quantum bits, or qubits. Scaling such systems could require thousands or millions of optical control channels.

The ski-jump architecture could help address that challenge by enabling a chip to steer beams across large arrays of quantum devices.

A Microscopic Mechanical Scanner

The device itself is incredibly small.

Fabricated using standard CMOS semiconductor processes, the structure consists of a nanoscale silicon-nitride waveguide embedded within a layered cantilever roughly two micrometers thick.

The cantilever is actuated by aluminum nitride piezoelectric layers. When voltage is applied, these layers expand or contract slightly, causing the structure to bend and oscillate.

Because the cantilever has extremely low mass, it can vibrate at kilohertz frequencies with high mechanical quality factors. Those vibrations translate into rapid motion of the beam exiting the tip of the waveguide.

By driving the device at different frequencies along two axes, the researchers generated Lissajous scanning patterns—the same type used in some laser displays—to create two-dimensional images.

The team also showed that the device can operate across a broad optical spectrum and can be integrated with other photonic components on the same chip.

Limitations and Next Steps

Despite the promising demonstrations, the technology remains in the experimental stage.

The current devices perform best in vacuum environments, where reduced air resistance allows the cantilever to vibrate more efficiently. Packaging the system into compact vacuum modules will likely be necessary for practical deployment.

The scanning approach also relies on resonant motion, meaning the beam follows repeating patterns rather than moving freely to any location at any moment. Future systems may require arrays of devices or additional optical control to achieve full random access scanning.

Researchers suggest that scaling the concept to large arrays of ski-jump emitters could eventually produce optical systems capable of generating billions of resolvable beam spots per second.

Such systems could form the basis of compact light engines for sensing, communication and machine vision.