Optical testing involves measuring the laser diode's output power, wavelength, spectrum, and beam profile. These parameters are critical for laser diode applications that require precise and stable optical performance, such as fiber-optic communication systems and optical sensors. 📦 For purchasing, use the RP Photonics Buyer's Guide for laser diode testing. What is Laser Diode Testing? Why is laser. The light-current-voltage (L-I-V) sweep test is a fundamental measurement that determines the operating characteristics of a laser diode (LD). The versatile LIV Test System combines source and measurement. This comprehensive guide dives deep into the methods and considerations involved in testing laser diodes using a multimeter, providing practical insights and actionable steps for ensuring accurate results and preventing costly errors.