Baseband frequency response measurement system for optical components

Knowledge of the baseband frequency responses of optical components is prerequisite to the design of optical fiber transmission systems. The sweep-frequency method is effective for obtaining frequency responses because of its large SNR. However, the use of GaAs lasers as optical signal sources involves several problems such as resonances below 1 GHz and spectrum broadening. In order to overcome these problems, a single transverse mode GaAs laser called a buried heterostructure GaAs laser was employed as an optical signal source in the sweep-frequency measurement system. This measurement system has a wideband flat sweep-frequency range of 0.5-1300 MHz as well as a wide dynamic range of more than 60 dB at optical levels.