A ‘bright’ future for electronics - advances in optics

The field of electronics has witnessed a rapid rise in innovation, under pressure from the growing needs for information technology to process more information faster and for the devices to be as small as possible. For electric signals to be processed reliably, electronics must have appropriate wiring structures, but traditional technologies using metallic wiring have several drawbacks—they produce signal errors, are bulky, and require excessive energy.

To avoid these pitfalls, scientists at Tokai University’s Department of Optical and Imaging Science and Technology, led by Prof Osamu Mikami, have been developing effective solutions using optical technologies that can offer more efficient signal processing with less energy demands. Prof Mikami said: “Devices using optical interconnection have several advantages such as lower power consumption and higher density package. We confronted this challenge by using a novel technology to connect optical devices to electronics, achieving ‘optical interconnection’.”

When combining optic and electronic devices, precise alignment of its structures is vital, especially when combining pins with waveguides (two structures essential in optical signal processing). In a study published in IEEE Xplore Digital Library, Prof Mikami and his team came up with a novel method called the ‘photomask transfer method’, which involved the irradiation of light from a fiber to a type of resin. Using this method, they created self-written waveguide optical pins, which surpassed the performance of traditionally used optical pins.

Based on this approach, many more developments could be produced. Prof Mikami said: “Using our technology, several new optical interconnect devices and connection technologies have been proposed and investigated.” For example, because their approach was challenging for multi-channel optical waveguides, in another study, they developed a new chip device solution featuring a polymer outlet rod surrounded by cladding. In another example, the research team designed several new optical devices based on this approach, which effectively improved the process of optical interconnection.

The team’s optical technologies have been applied to printed circuit boards - the basic building block of any electronic device - by combining optical and electronic wiring. Metals such as copper have usually made up electronic wires and have tended to host a ‘bottleneck’ of signals, which can cause data transmission errors and delays. Optical wirings avoid these problems, but having transitioned from single to multiple layers, it has proven difficult to connect all wires at once. Within the collaboration, two scientists even proposed an ‘optical socket’ that aligns all connections—this is now considered one of the best solutions for connecting optical wires.

This collaborative research in Japan demonstrates how optics can help to override issues experienced by traditional electronics using electronic wiring. In the future, this research could help innovators to create improved optoelectronic devices to keep up with modern technology demands.