The Final Stage of the Optical Revolution: Photonic Computers
The photonic revolution began with optical fibre, but it will end with optical computers. The German company Q.ANT has designed and is manufacturing itself one of the first all-optical commercial line of computers. Photonic computers are really analogue calculators. The advantage over electron-based digital computers is not the speed of light versus electrons. Their velocities are similar. Instead, the real difference is that digital computers flip zeros and ones using transistors in combination with capacitors. Capacitors must charge and discharge. This takes a lot of time. It also consumes a lot of power all of which ends up as heat. 😃Even a simple addition of two numbers requires approximately 200 transistors. Taking the square root of a number involves 7000 transistors and the work horse Fourier transformation requires roughly 1 million transistors. Note that glasses also passively perform a Fourier transformation. In other words a single optical device in a computer can do a...