It’s typically the time of the year for ‘technology watchers’ to look back and make rankings of the most promising technology innovations of the past year. ‘Laser Focus World’ magazine did this as well, resulting in a UT invention that is ending high in their optics/photonics top 20. It is the on-chip ‘optocoupler’, connecting two worlds on one and the same chip. In this way, for example, very sensitive electronics can be connected to high-power electronics. Or photonics can be combined with electronics. The invention, by Ray Hueting and Anne-Johan Annema, was in the news beginning of this year.
The invention that was presented in January, is called an ‘optocouper’, connecting two worlds on a chip without any electrical connection. Why would that be interesting? Imagine, a chip is connected to a sensor that is connected to your body. The same chip is also used to switch on a device that is connected to the mains. Those are two worlds: that of the highly sensitive sensor, with low currents and voltages, and that of high voltage and power. It speaks for itself that these worlds should be kept separate. This is possible by making the connection using light instead of electrical currents. This is called ‘galvanic isolation’.
Optocouplers have been there for a long time, as separate and quite bulky devices. What would be great, is including the optocoupler ‘on-chip’. This is not at all trivial, using the standard CMOS manufacturing technology for chips. Silicon, as a matter of fact, is not a very good light source. Still it isn’t impossible, PhD candidate Vishal Agarwal proved in January. He had worked out an original idea by Ray Hueting, of the Integrated Devices and Systems group, and Anne-Johan Annema of the Integrated Circuit Design group.
According to Laser Focus World, this is a ‘leading edge’ invention for combining the worlds of electronics and photonics. Laser Focus World is an American monthly magazine on developments in optics, photonics and laser technology, in science and industry. It started already in 1965.