If you connect a variable power supply to a cheap red laser pointer, and gradually increase the voltage from 3 volts, the output power will increase to a peak, then fall as voltage is increased further. It is quite safe from the laser's point of view to run at this peak, but watch the power dissipation in the series resistor. So far, best results are 7mW from a <1mW laser pointer.
While on the subject, if you look at a spot of laser light, you will see a grainy pattern, which will be in focus. If you put a lens over your eye, so that you can't see anything else, the grainy pattern will still be in focus. Only coherent light will do this.