The ability to be both receiver and transmitter is a red herring.. every optical semiconductor can do that. The innovation here is the modulation speed. Higher speeds for your fiber cable.
Thanks for pointing this out. I was confused when I initially read the article.
Only have access to the abstract but it looks like they are basically converting optical diode to a BJT to modulate bias current. (Might be pulling this out of my 6'o'clock positioned chemical vapor deposition chamber though, haha)
The word "diode" is linguistically built on the concept that it's a two-terminal device: "di" means two, "-ode" is the same as in "electrode", "anode", "cathode", ...
A three-terminal device is a triode. However, unlike diode, that term is used exclusively for the vaccuum ones: i.e. arrangements of an anode, cathode and grid. With diodes we have semiconductor diodes as well as vacuum (or thermionic) diodes.
"Researchers at the University of Science and Technology of China (USTC)'s iGAN Laboratory led by Prof. Haiding Sun and other institutes in China recently developed a new three-terminal diode that can both emit and detect light."
Considering the topic of a new photo-diode, the professor's name is perhaps unfortunate.*
> What is the maximum presumed distance over which photon emissions from blue [sapphire,] LEDs can be entangled? What about with [time-synchronized] applied magnetic fields? Could newer waveguide approaches - for example, dual beams - improve the distance and efficiency of transceivers operating with such a quantum communication channel?
> [...]
>> Physicists at the University of Konstanz have generated one of the shortest signals ever produced by humans: Using paired laser pulses, they succeeded in compressing a series of electron pulses to a numerically analyzed duration of only 0.000000000000000005 seconds [...]
>> For Peter Baum, physics professor and head of the Light and Matter Group at the University of Konstanz, these results are still clearly basic research, but he emphasizes the great potential for future research: "If a material is hit by two of our short pulses at a variable time interval, the first pulse can trigger a change and the second pulse can be used for observation—similar to the flash of a camera"
So it's a detector and an LED smashed together instead of combining discrete components into a TXRX module. It sounds more like a triode or transistor variant, but with multiple features.