Researchers from the University of Southampton have developed a new technique to help produce more reliable and robust next generation photonic chips.
A photonic chip uses light instead of electricity and is being developed for the production of ultra-fast quantum computers with capabilities far beyond today’s devices. As the complexity of optical chips increases, testing such chips becomes more difficult.
Southampton researchers have now developed a new method, which will help solve this problem, to find out at which time the light in the chip is at which position. The technique, called Ultrafast photomodulation spectroscopy (UPMS), uses ultraviolet laser pulses of femtosecond duration to change the refractive index of silicon in a tiny area on the photonic chip.
]Project leader Dr Roman Bruck explained: “Monitoring the transmission of the chip while the refractive index is locally changed gives a precise picture of how the light flows through it.
“This allows testing of individual optical elements on the chip, a crucial step in the design optimisation to ensure its flawless operation.
Because the changes induced by the technique are fully reversible, this testing method is non destructive and after testing, the chip can be used for its intended application.”
The new technique has the potential to be used for industrial testing in the photonics industry, said the paper that appeared in the journal Nature Photonics.