I want to build a 2-way serial communications rig using low cost LED lasers. 9600 baud would be ok, but faster speeds would be more useful. (This is purely a hobby project. The further I can establish a communications link the cooler it will be, but there is no hard requirement.)
Initially I'll probably use red LED lasers because they're easy to aim, but will eventually switch to IR. My thinking is that I will put an iR phototransistor in a parabolic reflector (like an old car headlight assembly) and put a cheap visible light blocking/IR pass filter in front (An "IR notch filter" to use signal processing terms for an optical filter) and put the whole assembly in a cylindrical tube. That way ambient light will be greatly attenuated and with the parabolic reflector pointed roughly in the direction of the sending laser even a "near miss" should be enough to generate a decent signal in the receiver, and if the beam is bigger due to being scattered over distance, the parabolic reflector will serve to focus it on my receiving phototransistor.
The dirt-simplest way to do this would be to power an off-the-shelf laser pointer through a transistor, and apply a CMOS level control signal to the gate of the transistor.
However I suspect that the voltage/current regulator on the laser pointer would tend to flatten out the high frequency switching of the power and prevent clean switching of the signal. (Most voltage regulators I've seen include one or more capacitors to flatten out the signal) Am I right in my suspicions?
I could buy a laser diode, regulator, and collimating lens and attempt to switch the output of the regulator into the laser diode, but I'm a software developer who likes to tinker with electronics, not an EE.
Are there low-cost solutions to sending digital signals with LED lasers? I'm willing to spend money on it, but would like to keep the costs down.