Researchers at The University of Queensland say they have found a way to make lasers – which are widely used in optical data communication – faster and improve their performance. Measuring the properties of lasers is vital to making improvements but, until now, say the researchers, there has been no method to fully capture this complexity.
Partnering with leading laser manufacturer II-VI Inc., the researchers have developed a tool that measures the output of vertical-cavity surface-emitting lasers (VCSELs) and allows the examination of the large amounts of data their light carries.
“The system itself is about the size of a shoebox and is simply inserted into the path of the laser beam,” says University of Queensland Research Fellow Dr Martin Plöschner from the School of Information Technology and Electrical Engineering (ITEE). “It can tell us how the laser beam evolves in time and changes its shape and color. That information is crucial to how the beam travels through the fiber link.
The results, say the researchers, can now be used to improve the next generation of lasers to help address the data “capacity crunch” – the ever-increasing demand for faster and more frequent access to data that is pushing optical fiber networks around the world to their limit. Laser light pulses relayed along the glass or plastic fibers travel at different speeds and can overlap, slowing down the process.
“Imagine yelling to a friend through a long concrete pipe,” says Dr Joel Carpenter from UQ’s ITEE. “Your message will distort depending on how much the pipe echoes, and you’ll also have to wait for the echoes to die down from one message before you can send the next. It’s a similar problem in large groups of computer servers, with the amount of echo dependent on the shape and color of the lasers being launched into the optical fiber.”
The new tool, say the researchers, will make it possible to identify the beam features that contribute to ‘pulse spreading’ in the optical link, which slows down data.
“Laser engineers can then design lasers without these rogue features, leading to optical links with higher speed and longer distance of operation,” says Plöschner. “And any tool that can facilitate faster data transfer over longer distances is helpful.”
Improved laser technology is set to benefit a range of industries, from telecommunications to security and car manufacturing, say the researchers.
“Autonomous cars use lasers to make a 3D image of the scene to help them navigate through traffic or reverse park in a tight spot,” says Plöschner. “And you’re scanned by hundreds of tiny lasers every time you use facial recognition to unlock your smartphone. It comes as no surprise then that there’s a huge demand to make lasers with improved performance. This breakthrough will unlock an information treasure trove of optical beams.”