Nanowerk, physicists at ETH-Zurich have developed the smallest electricallyumped laser in the world that could revolutionize chip technology ("Microcavity Laser Oscillating in a Circuit-Based Resonator").
The laser is 30 micrometers long, eight micrometers high and has a wavelength of 200 micrometers. This makes the laser considerably smaller than the wavelength of the light it emits – difficult, as lasers normally can’t be smaller than their wavelength! So instead of using a resonant cavity, the researchers used an electrical resonant circuit made up of an inductor and two capacitors where the light is effectively “captured” in it and induced into self-sustaining electromagnetic oscillations on the spot using an optical amplifier.
This means the size of the resonator is no longer limited by the wavelength of the light and can in principle be scaled down to any size. This makes the microlaser very interesting for chip manufacturers as an optic alternative to the transistors. “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”, says researcher Christoph Walther.