In the beginning, there was the photon. Originally "discovered" by Albert Einstein and called lichtquanta, (German for "particle of light"), it ushered in (and became the namesake for) the new field of quantum mechanics. Generating photons is easy: cavemen have been creating photons since the invention of fire. But these photons are unruly and uncontrolled. A candle, lightbulb, flashlight, all basically work on the same principle: inject some energy and photons of all colors (wavelengths) are released in all different directions. The big breakthrough in harnessing photons came with the invention of the maser, then the laser, starting in the 1950s. The unruly photon was tamed, channeled into a steady flow of single wavelength/color photons marching in the same direction, efficiently delivering their packets of energy with minimal loss and scattering. Lasers changed the world, especially for high-speed communications. By rapidly turning a laser off and on, a rapid stream of zeros and ones, known as bits, are efficiently routed through the glass of fiber optic cables or through space. While we rely on RF signals or ethernet cables for our internet usage, 95% of the world's data is delivered via laser across the seas. But our ability to manipulate photons hasn't stopped there. We now have the ability to manipulate and measure the quantum properties of individual photons, and even create pairs of photons that are entangled. Unlike classical communications that use lots of photons to create bits, in this case each photon becomes a source of quantum information: a qubit. Since a qubit is fundamentally random, it is not a good source for transferring classical communications. But it is very secure: if designed properly, only the transmitter and receiver can decode the hidden information contained in a qubit, thwarting a potential eavesdropper. But this is the tip of the iceberg. Just as the invention of the laser in 1960 led to new applications unforeseen at the time, today we are starting to realize new applications unleashed by the quantum properties of photons (see below).
Last Newsletter Theme: Zero Trust in the Quantum Era
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