Laser controlled ultrafast liquid switch for terahertz radiation

Researchers at Ruhr University in Bochum, Germany have developed an ultra-fast water-based switch. A short and powerful laser pulse can transform water into a conductive state in less than one trillionth of a second (10-12 seconds). During this time, its behavior is almost like metal, which makes it faster than the fastest semiconductor switching speed known so far.

Figure 1 Water is dispersed through a specially developed nozzle, and then the laser passes through it

Laser makes water behave like a high-speed switch
Now all operations of computers and smart phones are based on circuits. The components in the circuit switch between state 0 and state 1, and the speed of switching ultimately determines the running speed of the computer. However, the use of semiconductors in modern computers makes electrical switches possible, but their speed is inherently limited.

Author Dr Claudius Hoberg and his colleagues developed a possible water-based circuit method. The researchers fanned out the water dissolved in iodide ions in salt water through a special nozzle to form a flat jet with a thickness of only a few microns.

"You can think of it as squeezing the gardening hose to make the water flow wide and flat, but the scale is much smaller," Hoberg explained.

Then a short and powerful laser pulse is guided through the water jet. The laser releases electrons from the salt dissolved in water, which makes water suddenly become conductive at terahertz frequency, showing characteristics similar to metal. A short laser pulse duration of 10-14 seconds turns water into an ultra-fast switch.

Claudius Hoberg said, "At present, a conversion rate of 10-12 seconds has been observed in the terahertz range. The second laser is used to detect the state of water."

Source: phys.org