14 DAY TRIAL // A group of physics experts from Switzerland, at ETH-Zurich, have recently developed the smallest microlaser in the world that can be powered up using electricity. The achievement is bound to have significant implications in many research areas of physics, chemistry and medicine. Additionally, the team says, it could one day lead to the development of technologies that would revolutionize the way in which modern-day computer chips and microprocessors are built. The idea took about 18 months to be applied in practice, the team adds, quoted by PhysOrg.
The idea was first proposed by ETH-Zurich Quantum Optoelectronics Group PhD student Christoph Walther, who laid out its foundations over several weeks of work in ETH's FIRST laboratory. This is a modern, state-of-the-art clean room at the university, which provides ideal condition for precisely this type of work. Creating such small and intricate pieces of advanced technology in regular conditions would have been nearly impossible, given that foreign contaminants would have hindered the effort. In the end, Walther teamed up with four colleagues, and together developed the minute microlaser.
An impressive achievement of the new device is that it's smaller than the wavelength of the light it emits, which is another scientific record. The instrument is no longer than 30 micrometers (a micrometer is the millionth part of a meter), is about 8 micrometers high, and is capable of producing light at a wavelength of 200 micrometers. Generally speaking, lasers tend to be larger than the wavelength of the electromagnetic radiation they produce, simply because they use mirrors in their optical resonators, which forces light to bounce back and forth between the reflective surfaces.
The basic principle of lasers only works in devices that have mirrors larger than the wavelength of the light being amplified, which is a limitation that physicists have been struggling to overcome for decades. “By developing a completely new laser concept we were able to go quite a way below the limit,” Walther says. “Instead of the usual optic resonators, we use an electrical resonant circuit made up of an inductor and two capacitors,” he adds of the innovation that made the new microlaser possible.
“This means the size of the resonator is no longer limited by the wavelength of the light and can in principle – and that’s what makes it so special – be scaled down to whatever size you want. If we manage to approximate the transistors in terms of size using the microlasers, one day they could be used to build electro-optic chips with an extremely high concentration of electronic and optic components,” he concludes.