Abstract: The principle of frequency response measurement has been established using the optical heterodyne method, and the optical heterodyne method is used for measuring the frequency response of broadband sampling oscilloscope filter. The polarization and wavelength stability of light source are analyzed for the influence of the test results. The experiment result shows that, the optical heterodyne method testing frequency response of broadband sampling oscilloscope filter is feasible. Testing 9.953Gbps filter, the frequency response repeatability of 3dB bandwidth is less than 0.1dB.

Key words: Measurement, Frequency response, Optical heterodyne interference method, Broadband sampling oscilloscope, Filter