The 828B High-Speed Optical Wavelength Meter from Bristol Instruments is designed to provide accurate wavelength information at an unprecedented rate of 1 kHz. It revolutionizes WDM wavelength testing applications by reducing test times from hours to minutes. The 828B also features time resolution of 1 millisecond, providing the most detailed wavelength characterization of tunable WDM lasers. This application note presents a demonstration of the 828B’s capabilities when used to measure the absolute wavelength of an external cavity diode laser as it was tuned.