A research team from Chalmers University of Technology has introduced a new amplifier that allows the transmission of ten times more data per second than those in current fiber optic systems. The amplifier, which fits on a small chip, holds potential for various critical laser systems, including those used in medical diagnostics and treatment. To ensure that information maintains a high quality and is not overwhelmed by noise, optical amplifiers are essential. The data transmission capacity of an optical communication system is largely determined by the amplifier's bandwidth, which refers to the range of light wavelengths it can handle. “The amplifiers currently used in optical communication systems have a bandwidth of approximately 30 nanometers. Our amplifier, however, boasts a bandwidth of 300 nanometers, enabling it to transmit ten times more data per second than those of existing systems,” said lead author and professor of photonics Peter Andrekson. The amplifier developed by Chalmers University researchers measures just a few centimeters, yet it can process ten times larger amounts of data per second than current optical communication systems. The amplifier features a pattern of spiral-shaped, interconnected waveguides that efficiently direct the laser beam with high precision and minimal loss. Courtesy of Chalmers University of Technology/Vijay Shekhawat. The new amplifier, made of silicon nitride, features several small, spiral-shaped, interconnected waveguides that efficiently direct light with minimal loss. By combining this material with an optimized geometric design, several technical advantages have been achieved. “The key innovation of this amplifier is its ability to increase bandwidth tenfold while reducing noise more effectively than any other type of amplifier. This capability allows it to amplify very weak signals, such as those used in space communication,” said Andrekson. Additionally, the researchers have successfully miniaturized the system to fit on a chip just a few centimeters in size. “While building amplifiers on small chips is not a new concept, this is the first instance of achieving such a large bandwidth,” said Andrekson. The researchers have integrated multiple amplifiers onto the chip, allowing the concept to be easily scaled up as needed. Since optical amplifiers are crucial components in all lasers, the Chalmers researchers’ design can be used to develop laser systems capable of rapidly changing wavelengths over a wide range. According to the researchers, the innovation opens up numerous applications in society. “Minor adjustments to the design would enable the amplification of visible and infrared light as well. This means the amplifier could be utilized in laser systems for medical diagnostics, analysis, and treatment. A large bandwidth allows for more precise analyses and imaging of tissues and organs, facilitating earlier detection of diseases,” said Andrekson. In addition to its broad application potential, the amplifier can also help make laser systems smaller and more affordable. “This amplifier offers a scalable solution for lasers, enabling them to operate at various wavelengths while being more cost-effective, compact, and energy efficient. Consequently, a single laser system based on this amplifier could be utilized across multiple fields. Beyond medical research, diagnostics, and treatment, it could also be applied in imaging, holography, spectroscopy, microscopy, and material and component characterization at entirely different wavelengths,” said Andrekson. Light at different wavelengths serves various applications. The researchers have demonstrated that the amplifier functions effectively within the optical communication spectrum, ranging from 1400 to 1700 nm. With its extensive bandwidth of 300 nm, the amplifier can potentially be adapted for use at other wavelengths. By modifying the waveguide design, it is possible to amplify signals in other ranges, such as visible light (400 to 700 nm) and infrared light (2000 to 4000 nm). Consequently, in the long term, the amplifier could be used in fields where visible or IR light is essential, such as disease diagnosis, treatments, visualization of internal organs and tissues, and surgical operations. The research was published in Nature (www.doi.org/10.1038/s41586-025-08824-3).
