|What type of laser is in a laser printer? — DFC, Asheville, NC
A laser printer uses a single diode laser that's scanned across the surface of the photoconductor drum by a rapidly turning, multifaceted mirror. These diode lasers are very similar the ones used in laser pointers or supermarket barcode readers. The multifaceted mirrors are typically octagonal prisms that are aluminized to make them highly reflecting and spun by a motor. The laser beam bounces off the spinning mirror and its reflection sweeps across the photoconductor. Modulating the current supplying power to the diode laser causes its brightness to fluctuate so that it writes information on the surface of the photoconductor.