The Keysight / Agilent / HP 83430A is a modulatable DFB laser source that converts digital input signals to a preset optical output level that is SDH/SONET compliant. It is designed to evaluate the performance of high-speed TDM (time division multiplexed) and WDM (wavelength division multiplexed) optical receivers and systems to SDH/SONET OC-1 (51.84 Mb/s) through STM-16/OC-48 (2.488 Gb/s) standards.