The Keithley Model 2520INT Integrating Sphere is designed to optimize the Model 2520 Pulsed Laser Diode Test System's optical power measurement capabilities. It allows the testing of devices with pulse widths as short as 500ns. The short pulses of the Model 2520 combined with the speed of the Model 2520INT make them ideal for measuring the optical power of laser diodes at the bar or chip level, before these devices are integrated into temperature-controlled modules. When connected to the Model 2520 via a low noise triax cable, the Model 2520INT allows the Model 2520 to make direct, high accuracy measurements of a laser diode's optical power. The results are expressed in milliwatts.