Two types of system I can think of:
A Laser.
an electromagnet
SPECTROSCOPE!! or a prism
Any electrical device that you connect it to.
Laser
a monitor
A printer is a device that produces soft copies of digital documents by transferring text and images from a computer onto paper.
The name of the device that produces coherent light is LASER.
The name of the device that produces coherent light is LASER.
A heater?
anything that has an arm
A dry cell.
Double Convex
A Laser.
A dynamo
it produces a hardcopy and softycopy of results
Geiger Counter