This new element would be called LED.
Description: Light Emitting Diode. PSCN powers, NSCN turnes off. Emits a stream of photons.
What it does: Emits stream of photons when powered with PSCN. Turnes off when powered with NSCN. Changing its color with CTYPE (i think) changes color of photons emitted.
Uses: It is easier to make photon lasers. Lasers can be made smaller. Just there for convience.
Category: Electronics
Light Spread:
In a straight line. Like this:
LED:=========
what you described is basically this:
The color of the laser was set by the filt, and the color of the filt is determined by its ctype. The laser is already pretty small, no need to add another element just for this.
It does work. Spark the PSCN to turn it on and NSCN to turn it off.