Recently, researchers at Columbia University in the United States unexpectedly discovered a new method capable of generating multicolor lasers on a single chip while developing LiDAR technology. This innovation holds promise to revolutionize data centers and communications by providing faster, cleaner, and more efficient light sources.
Several years ago, the research team in Michal Lipson's lab focused on designing high-performance chips capable of generating stronger beams while seeking LiDAR improvements. Former postdoctoral researcher Andres Gil-Molina explained: "As we continuously increased the chip's output power, we noticed it was generating what's known as a 'frequency comb.'" A frequency comb is a unique beam composed of numerous distinct colors (light frequencies) arranged in a strict, equidistant pattern, similar to a rainbow's structure. On a spectrum, each color appears as a distinct, bright "tooth" separated by dark regions, enabling simultaneous transmission of multiple data streams-each tooth acting as an independent data channel.
Previously, generating powerful frequency combs required bulky and expensive lasers and amplifiers. The latest research reveals that the same effect can now be achieved within a microchip. Lead researcher Professor Lipson, from Columbia University's Department of Electrical Engineering and Applied Physics, stated: "Data centers have a massive demand for powerful, efficient light sources encompassing numerous wavelengths. Our technology transforms a single powerful laser into dozens of high-quality signal channels. A single chip can replace rows of standalone laser devices, saving space and costs while significantly boosting system speed and energy efficiency."
Lipson added: "Advancing silicon photonics has been our mission. As this technology becomes increasingly integrated into core infrastructure and daily life, such breakthroughs are crucial for ensuring efficient data center operations."
The breakthrough stemmed from a simple question: How powerful a laser can we fit onto a chip? The team selected multimode laser diodes, widely used in medical devices and laser cutting. While these lasers deliver immense light energy, their beam state is highly "disordered," making them unsuitable for precision applications. To address this, researchers introduced a "locking mechanism" that leverages silicon photonics to purify the beam output, making it cleaner and more stable-a phenomenon known scientifically as "high coherence." .
Subsequently, the chip's nonlinear optical properties took effect, splitting a single high-intensity laser into dozens of equidistantly spaced colors. This created an efficient, compact frequency comb light source combining the intensity of industrial lasers with the precise stability required for high-end communications and sensing.
With explosive growth in fields like artificial intelligence, internal information transmission within data centers has become increasingly urgent. Although fiber optics are now widely used for data transmission, single-wavelength lasers remain predominant. The multi-channel parallel transmission capability enabled by frequency combs allows dozens of data streams to be processed simultaneously within a single fiber, significantly boosting transmission efficiency and speed. This injects new momentum into high-speed networks and modern computing systems. This innovation not only promises to drive the miniaturization and efficiency of data centers but also finds applications in portable spectrometers, optical clocks, quantum devices, and advanced LiDAR systems.
The research team stated, "This technology aims to bring laboratory-grade high-performance light sources into practical devices. If sufficiently powerful, efficient, and compact, it could be applicable in virtually any scenario."
