Laser pwm low power

brettw wrote:

Checked and it is +1. Maybe my laser is bad. Have tried another computer with a parallel port card added and same result.

Is the voltage 5V without the laser connected and less with it connected?

If so that points to a low impedance input to the laser.

An Op-amp in voltage follower mode is a fairly simple solution in that case. You can dead-bug the circuit and wrap in tape / heat-shrink.
Here is one (and the data sheet) with a 1A output... (if you need more than that the laser definitely is broken)
uk.rs-online.com/web/p/op-amps/1844764/
For voltage follower no other components are needed:
www.learningaboutelectronics.com/Articles/Voltage-follower
www.instructables.com/id/Dead-Bug-Protot...reeform-Electronics/