DIY 200mw DVD Red Laser

I've always loved lasers and never really played around with them simply cause I've never owned one, but the thing that impresses me the most is to see a laser show that is sound activated.

All you need to know about Laser Diodes

Objective: build a 3 color sound activated laser.

The Build:

I was given a couple of cheap laser pointers and thought it would be cool to make a laser show starting with the 2 pointers but quickly found out they really don't last too long. In only 10 minutes the laser would die and I'd have to replace the 3 button cells, fortunately I had a lot of button cells on hand but at this rate I'd exhaust my supply in no time so I'd have to start by building a current regulated power supply.

Heres the schematic I used to regulate the current flow, this circuit was then connected to a supply voltage (wallwart set to 6volts).


I salvaged a laser diode out of a scrap 16X DVD burner, I also removed the lens housing found in small laser pointers and installed it into a large computer cpu heat sink.


After watching the laser beam for awhile I got board and decided to make it do something other then make a red spot on the wall, I took 2 small motors from a dvd and glued small mirrors to the top of the gears.


Here I glued small pieces of rubber bands to the mirror and the other end to the case of the motor, this stops the motor from making a 360 degree turn.


And heres a little laser show :)




The New Laser Driver:



I can't seem to salvage different colored diodes like green, yellow or blue so I ordered 2 50mw laser diodes, one green and one blue. I also made changes in the way I drive the 2 dynamometer, I orignally used 2 of the speaker outputs from my radio but should not be done in this fashion so the unit will now contain its own audio amplifer making it much simpler to connect using a line out from your audio signal.
Also the effect called blanking can be acchived by using a simple flasher or strobe circuit controling the lasers power input.

Laser CAD:
Image
Using a signal generator with my laptop connected to the left and right inputs of the laser I was able to create extremely complex animated patterns and shapes. Simply by recording 5 second periodes of the different wave forms created by the signal generator I was able to produce different effects that would automaticly change every 5 seconds. You could actually just save your wave forms into mp3 format and play them from an mp3 player.