Powering Up the Laser Diode

Double check your pin/terminal connections. For bare laser diodes (especially high power ones rode/groene/blauw/triplex krachtig laserpointer ), the heatsink is almost always the ANODE (positive) and the top terminal is the cathode (NEGATIVE). (I've only come across one exception and the diodes were some kind of specials labeled "R&D".) This is the reverse of what most engineers expect and I've blown more than one laser diode due to lapses in concentraion! For packaged laser diodes, there is no standard! Close is only valid in horseshoes and hand grenades - with laser diodes, it often means total destruction! :)

If you leave the laser diode connected when you turn the supply on and off, and aren't using one intended to drive a laser diode, transients will kill the diode in short order groene laserpointer 2000mw . I have been doing failure testing of a few of my diodes, and have put over 1,000 hours on them now. For this testing I'm using plain old lab supplies, and diode degradation is still right on the curve where the vendor said it should be.

Note that if you have a device from a CD player, CDROM, or other optical drive with 8 or 10 pins, it is a combined laser diode and photodiode array in a single package. You will first have to identify the three connections to the laser diode itself. You should be able to determine this by tracing the wiring - there may even be markings on the circuit board. In many cases, the laser diode is driven by discrete components whereas everything else goes to a preamp IC. Once the pinout of the laser diode is determined, it can be treated in exactly the same way as the more common 3 pin type.

For a current below the lasing threshold for your laser diode, there will be some emission due to simple LED action. As you slowly increase the current, at some point (if the laser diode is good) as you exceed the threshold current groene laserpointer 3000mw , the character of the emission will change dramatically and a very slight increase in laser diode current will result in a significant increase in intensity. Congratulations! The laser diode is lasing.