ABSTRACT
In this chapter, the authors measure the transverse profile of the laser beam from a laser pointer by carefully moving an obstacle across the beam and observing the change of the signal from a photoresistor. They use a laser module from a sensor kit that is mounted on a breadboard and exposes two wires, one for ground and one for the positive supply voltage. The laser on its small breakout board is located at the top right with the stepper motor beneath and hidden from view, but the spindle is clearly visible, running right to left near the top of the frame. There it engages the white plastic part that is attached to the wagon and moves it, when the motor turns. On the wagon there is a black piece of plastic visible that intercepts the laser beam and prevents the laser from hitting the light-dependent resistor on the lower right on the frame.
