The Yokogawa AQ6375B is a high-performance Benchtop Optical Spectrum Analyzer (OSA) designed for the analysis of optical signals in the Telecom C-band and L-band. It covers a wavelength range from 1200 to 1650 nm, making it an essential tool for the development, manufacturing, and maintenance of components and systems for optical communication networks, such as DWDM (Dense Wavelength Division Multiplexing).