A lab accident has prompted engineers to create a chip that emits a rainbow of powerful laser beams – which could help data centers better manage exploding volumes of data. artificial intelligence (AI) date.
The new photonic chip contains an industrial-grade laser source combined with a precisely engineered optical circuit that shapes and stabilizes light before splitting it into multiple, evenly spaced colors.
Making this rainbow The effect, called frequency combing, typically requires large and expensive lasers and amplifiers. However, researchers have stumbled upon a way to package this powerful photonic technology into one tiny chip as they work to improve it. lidar (light detection and ranging) technology.
Lidar uses laser pulses to measure distance based on the time it takes them to travel to an object and return. While trying to create more powerful lasers that could capture detailed data from a greater distance, the team noticed that the chip splits light into multiple colors.
What is a frequency comb?
A frequency comb is a type of laser light consisting of multiple colors or frequencies that are evenly distributed over optical spectrum. On a spectrogram, these frequencies appear as peaks resembling the teeth of a comb.
The peak of each “tooth” represents a stable, precisely defined wavelength that can carry information independently of the others. Because the wavelengths are fixed in both frequency and phase (meaning their peaks remain perfectly aligned), they do not interfere with each other. This allows multiple data streams to be transmitted in parallel over a single optical channel, such as a fiber optic cable.
Having stumbled upon this effect by chance, scientists have developed a way to reproduce it intentionally and in a controlled manner. They also packaged the technology into a silicon chip, where light passes through waveguides that are only micrometers wide; one micrometer (1 µm) is equal to one thousandth of a millimeter (0.0001 cm) or approximately one hundredth the width of a human hair.
The team published their findings on October 7 in the journal. Natural photonics. This breakthrough is especially important now as AI hosts more and more load on data center infrastructure resourcesthe researchers said.
“Data centers have created enormous demand for powerful and efficient light sources that contain multiple wavelengths,” study co-author. Andres Gil-Molinachief engineer of Xscape Photonics and former researcher at Columbia Engineering, said in an interview statement.
“The technology we developed takes a very powerful laser and turns it into dozens of clean, powerful channels on a chip. This means you can replace racks of individual lasers with one compact unit, cutting costs, saving space and opening the door to much faster and more energy-efficient systems.”
Rainbow on a chip
To create a frequency comb on a chip, the researchers needed to find a high-power laser that could be squeezed into a compact photonic circuit. They eventually settled on a multimode laser diode, which is widely used in medical devices and laser cutting tools.
Multimode laser diodes can produce powerful beams of laser light, but the beam is “messy,” meaning researchers need to figure out how to improve and stabilize the light to make it workable, the researchers said in the study.
They achieved this using a technique called self-injection blocking, which involves integrating resonators into the chip that feed a small portion of the light back into the laser. This filters and stabilizes the light, resulting in a beam that is both powerful and very stable.
Once stabilized, the chip splits the laser beam into a multi-colored frequency comb. The result is a small but efficient photonic device that combines the power of an industrial laser with the precision needed for data transfer and sensing, the scientists added.
Beyond data centers, the new chip could power portable spectrometers, ultra-precise optical clocks, compact quantum devices and even advanced lidar systems.
“This is about bringing lab-grade light sources into real devices,” Gil-Molina said. “If you can make them powerful, efficient and small enough, you can put them almost anywhere.”
