A laser structure may be used to fabricate a plastic laser and achieve electrically-driven lasing action. The structure comprises an LED, a waveguide laser, and a substrate disposed between them. The substrate has a first and a second side. Light emitted from the LED is received by the substrate at the first side and concentrated as it is guided with the body of the substrate to the second side, where it is received by the laser. Concentration of the light across the substrate improves the efficiency of the device and leads to lower threshold powers.