Researchers from MIT and the University of Wisconsin–Madison have introduced a new optical rastering device. It generates arbitrary two-dimensional light patterns at a 1 MHz refresh rate—a major step for fast, flexible qubit control in neutral-atom quantum devices.
This system blends a virtually imaged phased array (VIPA) with a fast electro‑optic modulator (EOM) and a dual-axis deflection scheme. With this, it gets around the speed and geometric limits of traditional acousto‑optic deflectors (AODs) and spatial light modulators (SLMs).
In early demonstrations, the device produced a 40×40 active 2D pattern. There’s a clear path to roughly 100×100, which meets the demands of next‑generation quantum processors and hints at potential beyond just lab setups.
Technology Overview and Innovation
The core idea separates the light‑steering job into a rapid, one‑dimensional “fast” axis managed by a VIPA/EOM combo and a slower, two‑dimensional scan along a second axis. This architecture decouples speed from geometry, which means you get high‑resolution patterning without the old bottlenecks.
By integrating VIPA with a high‑bandwidth EOM and a dual‑axis feed, the device can rapidly reconfigure complex light patterns. That’s tailored to address many qubits in parallel.
The design leverages counter‑propagating acoustic waves to reduce acoustic lensing and keep resolution sharp at high scan speeds. That’s a key improvement over conventional AOD‑only systems.
Key components and operating principle
VIPA acts as a high‑resolution, fast-switching element, offering nanosecond‑scale control of spectral channels mapped to spatial positions. The EOM quickly modulates the light on the fast axis, so you can shape each channel dynamically in real time.
The dual‑axis deflection—a rapid “fast” axis and a slower scanning “slow” axis—coordinates the two‑dimensional rastering needed to form arbitrary light patterns across the target plane.
In practice, this setup yields a 2D raster that sculpts many simultaneous focal spots with precise geometry. The team reported a 4.8 ± 0.4 ns VIPA switching time (limited by detector bandwidth) and a dual‑axis access time of 260 ns, which is about 1.76× faster than a single AOD approach.
These numbers mean you get rapid, dense qubit addressing while keeping the optical geometry manageable for compact setups.
Performance metrics and current limitations
Static and active spatial resolutions reached 66 and 17, respectively. Individual beam spots measured about 15 ± 1 μm wide by 11.3 ± 0.2 μm tall.
At a 1 MHz refresh rate, the rasterer can transport atoms in steps of ~100 nm. That’s speeds approaching 0.1 μm/μs.
Overall transmission efficiency sits at around 2% due to losses in the fiber EOM, DAOD diffraction, and VIPA sideband throughput. The team expects improvements that could push power at the atoms toward the watt‑level—maybe up to 500 mW—enabling hundreds of movable traps in a single device.
- VIPA switching time: 4.8 ± 0.4 ns
- Dual‑axis access time: 260 ns
- Static resolution: 66
- Active resolution: 17
- Beam spot size: ~15 μm (width) × ~11.3 μm (height)
- Refresh rate: 1 MHz (~100 nm step capability in atom transport)
- Current transmission efficiency: ~2%
- Projected power at atoms: up to ~500 mW with improvements
To keep image fidelity sharp at high scan speeds, the team used counter‑propagating acoustic waves to cancel acoustic lensing. That distortion would otherwise degrade resolution in fast rastering.
This engineering choice is crucial for maintaining pattern integrity as the system scales to denser 2D patterns.
Applications, implications, and future impact
Beyond quantum computing, this arbitrary‑pattern, high‑speed steering rasterer could shake things up in LiDAR, volumetric fluorescence microscopy, and free‑space optical communications. Imagine sculpting light in two dimensions at lightning speed—suddenly, parallel addressing of big qubit registers looks a lot more doable.
This kind of rapid light control might also spark new imaging techniques and boost high‑bandwidth communication links. The device’s design—using a VIPA/EOM stack with a dual‑axis scanner to double up optical channels—lays out a path for future hardware to scale up qubit connectivity without making the whole system a tangled mess.
On the practical side, the mix of speed, sharp resolution, and watt‑level atom power makes this tech a real contender for speeding up quantum circuit design and simulation. Engineers and scientists now have a shot at parallel, high‑connectivity qubit control across larger neutral‑atom arrays, which means richer quantum algorithms and quicker hardware validation cycles.
Sure, the integration—especially the double‑AOD and VIPA/EOM coupling—brings some engineering headaches. But if it pans out, this platform could totally change the game for scalable quantum information processing.
Here is the source article for this story: Optical Device Steers Qubits In Any 2D Pattern