Caltech breakthrough brings fiber-optic performance to silicon chips
Caltech scientists have created ultra-low-loss optical pathways on silicon chips that approach the efficiency of fiber optics and dramatically outperform existing technology at visible wavelengths.
Silicon chips are set to become more powerful and efficient thanks to a breakthrough by Caltech researchers. They have developed a method to create ultra-low-loss optical pathways on silicon chips that approach the efficiency of fiber optics.
The new technology has the potential to unlock more powerful lasers, miniature atomic sensors and clocks, quantum systems, and more energy-efficient data centers. Optical fiber already forms much of the hidden infrastructure behind modern communications, allowing information to travel over long distances at high speed.
The researchers create waveguides using germano-silicate, the same type of glass used in optical fiber. They adapt the material to a lithography-based manufacturing method suitable for making devices on wafers. Instead of running in a straight line, the waveguides are arranged in spirals, allowing light to travel a much longer optical path while remaining inside a very small area.
At near-infrared wavelengths, devices built with the new Caltech platform have already matched the performance of some of the best previous devices made from silicon nitride. Silicon nitride is widely used in optical technology because it can transmit data with relatively little signal loss.
The advantage becomes much larger at visible wavelengths. The new germano-silicate platform substantially surpasses silicon nitride in this part of the spectrum. Reducing loss can have a dramatic effect on the performance of optical devices. Lasers produced with the new platform, for example, show more than a 100-fold improvement over previous designs in how long their light remains coherent.
The expanded wavelength coverage the method offers will support many important atomic operations, making chip-scale atomic sensors, optical clocks, and ion-trap systems possible. The ability to create ultralow-loss waveguides across visible wavelengths could be useful for many different technologies.
One of the reasons this is so compelling is that it has a Swiss Army-knife quality -- it can be applied in a wide range of settings. The researchers describe several devices made with the new material in their paper, including ring resonators, multiple types of lasers, and nonlinear resonators capable of generating a range of frequencies.
The researchers also see the current results as an early stage rather than an endpoint. They have made significant progress over the last five years, and that's what they're reporting on here. The paper is titled "Towards fibre-like loss for photonic integration from violet to near-infrared."
## New Technology for Photonic Integrated Circuits
The new technology has the potential to unlock more powerful lasers, miniature atomic sensors and clocks, quantum systems, and more energy-efficient data centers. The researchers create waveguides using germano-silicate, the same type of glass used in optical fiber.
## Low Loss Over Long Distances
The new germano-silicate platform substantially surpasses silicon nitride in this part of the spectrum. Reducing loss can have a dramatic effect on the performance of optical devices. Lasers produced with the new platform, for example, show more than a 100-fold improvement over previous designs in how long their light remains coherent.
## Applications of the New Technology
The expanded wavelength coverage the method offers will support many important atomic operations, making chip-scale atomic sensors, optical clocks, and ion-trap systems possible. The ability to create ultralow-loss waveguides across visible wavelengths could be useful for many different technologies.
## Conclusion
The new technology has the potential to unlock more powerful lasers, miniature atomic sensors and clocks, quantum systems, and more energy-efficient data centers. The researchers create waveguides using germano-silicate, the same type of glass used in optical fiber. They adapt the material to a lithography-based manufacturing method suitable for making devices on wafers.
| Device | Near-infrared wavelengths | Visible wavelengths | | --- | --- | --- | | Silicon nitride | 1 | 20 | | Germano-silicate | 1 | 400 |
The researchers also see the current results as an early stage rather than an endpoint. They have made significant progress over the last five years, and that's what they're reporting on here. The paper is titled "Towards fibre-like loss for photonic integration from violet to near-infrared.
