output pins were also 5v current, is that not the case?
The laser diode only has a power and ground wire.... I'm unsure of the current draw on the laser.
It's a green 5mW laser diode on an Uno board.
[5mW] Draws too much current for an output pin.
?P=VI and I=P/V5mW/5V = 1mA.....
The 5mw refers to the emitted power