Scientists have developed a new type of laser amplifier that can transmit information 10 times faster than current technology.
Laser amplifiers boost the intensity of light beams. This particular amplifier achieves a tenfold increase in transmission speed by expanding the bandwidth, or wavelengths of light, at which the lasers can transmit information.
The amount of information we generate and transmit is growing every day. Due to the proliferation of streaming services, smart devices and generative AI, Nokia Bell Labs predicted in their Global Network Traffic Report that the amount of data traffic will double by 2030.
Current optical-based telecommunication systems transmit information by sending pulses of laser light through fiber-optic cables, which are thin strands of glass. The capacity — the amount of information that can be transmitted — is determined by the amplifier’s bandwidth (the wavelengths of light that it can amplify). As data traffic increases, bandwidth therefore becomes crucial.
Most lasers used for modern telecommunications, such as internet communications, require an amplifier. These work by a process called stimulated emission, which uses an incoming photon to stimulate the release of another photon with the same energy and direction.
Scientists have now designed a new type of laser technology that can transmit information using a technology called high-efficiency optical amplification. The researchers published their findings April 9 in the journal Nature.
“The amplifiers currently used in optical communication systems have a bandwidth of approximately 30 nanometers,” lead author Peter Andrekson, a professor of photonics at Chalmers University of Technology in Sweden, said in a statement. “Our amplifier, however, boasts a bandwidth of 300 nanometers, enabling it to transmit ten times more data per second than those of existing systems.”
The new amplifier is made of silicon nitride, a hardened ceramic material that is resistant to high temperatures. The amplifier uses spiral-shaped waveguides to efficiently direct the laser pulses to remove anomalies from the signal. The technology has also been miniaturized so that multiple amplifiers can fit onto a small chip.
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The researchers chose spiral waveguides over other waveguide types because they enable longer optical paths to be created within a small area. This enhances useful effects such as four-wave mixing, which occurs when two or more optical frequencies are combined together to amplify the output with minimal noise (external interference that can disrupt the quality of the signal).
Because the speed of light is constant, the laser light itself does not travel any faster than that from conventional lasers. However, the larger bandwidth enables the new amplifier to transmit 10 times more data than conventional lasers can.
The amplifier currently functions in a wavelength range of light 1,400 to 1,700 nanometers, which is within the short-wave infrared range. The next stage in the research will be to see how it operates over other wavelengths, such as those for visible light (400 to 700 nanometers) and a broader range of infrared light (2,000 to 4,000 nanometers).
The new amplifier has multiple potential applications, including medical imaging, holography, spectroscopy and microscopy, according to the statement. The miniaturization of the technology could also make lasers for light-based applications smaller and more affordable.
“Minor adjustments to the design would enable the amplification of visible and infrared light as well,” Andrekson said. “This means the amplifier could be utilised 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.”
