How can you make logic gates with this?
It looks like this is just "shine a laser at a material to change it, and then use another laser to detect the difference."
"apply a voltage at a device to change it, and then use another voltage to detect the difference (i.e. to detect if a current passes)".
This is an optical switch, like a transistor is an electrical switch. An optical switch that is not very efficient, because the transmission is varied only between 100% and 80%, but one that is very fast.
It can be used in THz range mixers and oscillators.
"Put a voltage over a resistor and use an ammeter to detect the difference"
and make a resistor look like a transistor which it clearly isn't.
"""Because the laser pulse is so fast, the water can switch states in a matter of picoseconds, which are trillionths of a second."""
Although after reading, I must agree that the time-scale feels quite ridiculous!!
(EDIT: RE: "Capacitors can't be logic gates" below - Maybe. But if 1+0=1, and 1+1=2, then surely differentiating 0/1 vs 2 on the output creates an AND gate?)
(I am "posting too fast" with 3 posts in the last hour. Sorry :)
Ok, replace resistor by capacitor :)
I.e., run a current through a capacitor, then (some time later) measure the voltage over it.
I don't recall anyone actually creating logic gates using capacitors only.
In the definition of any controlled switch, e.g. transistor, optical switch or any other kind, it is essential that there are two distinct quantities, e.g. voltages or light beams, one that controls the output state and one that provides power to the output circuit.
A resistor corresponds to a tinted window, not to an optical switch.
Instead of trying to generalize the principle, why don't you explain how you can make logic gates using the technology of the article? And how can you tie these logic gates together without the signal becoming weaker between input and output?
> To replace electronic components with optical ones, an equivalent optical transistor is required. This is achieved using materials with a non-linear refractive index.
Nevertheless, it is unlikely to use such optical switches for logic gates. The most likely application for them is in mixers and oscillators.
There is no impediment for making a complex logic gate by an arbitrary series-parallel connection of the output light beams.
The output of such a logic gate cannot be connected to the input of an identical logic gate, because the input and the output light beams have different frequencies.
This is a problem common for many kinds of optical switches. It is likely that any conversion circuit that could be inserted between two such logic gates would be much slower than them, negating any speed advantage.
This does not really matter, because such optical switches are not intended for making logic circuits.