I have been working with Light Logic for over a year now and the name Light Logic fits quite well for the entire logic gate family ie. Not, And, Nand, Or etc....

What I have recently been looking into was a name for the Led/LDR pair and a few names have popped up such as....

NPV - Nesselhaus Photonic Valve @Starhawk 

IPV - Isolated Photo Varistor @Starhawk 

LLPT - Light Logic Photonic Transistor @Morning.Star 

Thanks for the cool ideas my friends.

But @Yann Guidon / YGDES  did some digging and came up with the Vactrol.

This opto-isolated buffer uses a Led coupled to a LDR in a very small package and the Vactrol name has been in use for quite a few years and used mainly in audio applications.

https://en.wikipedia.org/wiki/Resistive_opto-isolator

https://www.ebay.co.uk/itm/Audio-Optocoupler-Opto-Isolator-LED-LDR-package-vactrols-Circuit-Bending-/301866130538

So in the end I will follow along and use the name Vactrol for my Led/LDR pair.