All-Optical Nanowire Switch and Logic Gate Made
Much of the technology we use daily now is either electronic in nature, or uses electronics in some function, but in the future we may see other technologies take over these roles, including photonics. Instead of using electrons, photonics use photons to transmit data, and do so much faster and with less energy loss than modern electronics. Making photonics is tricky though, because light does not always play nicely at the nanoscale, but researchers at the University of Pennsylvania overcame this to make the first all-optical nanowire switch.
The researchers achieved this by taking a cadmium sulfide nanowire and cutting a gap into it. They then pumped enough energy into one nanowire segment to cause it to emit light, which crossed the gap and was absorbed by the other segment that then conveyed the light down its length, thus overcoming the difficulty of getting light into a nanoscale system. The researchers then found that by shinning another light onto the structure, they could turn it off, making an optical switch.
As interesting as such an optical switch is, the researchers pushed forward and made an even more impression device by combining the switches into a NAND gate. NAND gates are a fundamental kind of logic gate which can actually be combined in such a way as to perform any logical operation, so this discovery could really influence the future of photonics.