How do I identify laser diode connections? Answered

if it is a three pin diode and has the middle pin on the right side

the top pin is + middle is - and bottom controls something that i dont know

Trail and error is the best way but it depends on the type of laser diode.

. Use a multimeter with a "diode check" function. Many multimeters will do the job on x1 ohms, but there is a slight risk of sending too much current through the diode.