Phase and Amplitude Responses of Narrowband Optical Filter Measured by Microwave Network Analyzer

The phase and amplitude responses of a narrowband optical filter are measured simultaneously using a microwave network analyzer. The measurement is based on an interferometric arrangement to an split optical carrier into two paths and then combine them. In one of the two paths, a Mach-Zehnder modulator generates two tones without carrier, and the narrowband optical filter just passes through one of the tones with the inclusion of its amplitude and phase responses. The temperature and environmental variations are removed by separated phase and amplitude averaging. The amplitude and phase responses of the optical filter are measured to the resolution and accuracy of the network analyzer