This set of two circuits from the basis for a very simple light wave transmitter. A LASER beam is modulated and then aimed at a receiver that demodulates the signal and then presents the information voice, data, etc.. The whole thing is very easy to build and requires no specialized parts execpt for the LASER itself.
First, you will need a green laser anything 125 mW and above.You also need a diffractive glass that will distribute the green laser beams.You could probably use those cheap diffractive glasses from 3D glasses too.
There's something rather futuristic about talking 'over' a laser beam, which is what this inexpensive project allows. It will easily give a communication distance of several hundred metres, and with a parabolic light reflector, up to several kilometres. It transmits high quality audio and the link is virtually impossible for anyone else to tap into.
This train detector makes use of hand held laser pointer devices that are widely available to detect trains over long distances.
This circuit was originally designed to detect laser light pulses for an optical Ethernet communications system. It has good ambient light immunity.
circuit was originally designed to detect laser light pulses for an optical Ethernet communications system, good ambient light immunity
this circuit shows how to drive the laser device from a single high speed CMOS IC, circuit takes advantage of some new vertical cavity surface emitting lasers (VCSEL) that dont require light output control circuits
This circuit takes advantage of some new vertical cavity surface emitting lasers (VCSEL) that do not require light output control circuits. The circuit shows how to drive the device from a single high speed CMOS IC.