Phase frequency characteristic measurement method for tunable fiber Fabry-Perot (FFP) filter and application

Abstract

The invention provides a phase frequency characteristic measurement method for a tunable fiber Fabry-Perot (FFP) filter and application. The method comprises the following steps of: when the input signal frequency is low, adjusting the direct-current bias voltage of the tunable FFP filter so that the central wavelength of the filter is aligned with the wavelength of a laser device; when the inputsignal frequency is increased, recording time components of the peak value of input signals and the local minimal value of output optical signals through a digital storage oscilloscope; and calculating the phase difference between the local minimal value of the output optical signals and the peak value of the input signals by using the relationship between the period and the phase in a trigonometric function to obtain the phase frequency characteristics of the tunable FFP filter under different frequencies. By using the measurement result, the measurement error of the central wavelength of the tunable FFP filter can be calculated, and important reference basis is provided for time constant design of a locked loop in a wavelength locking controller.

Description

technical field [0001] The present invention relates to a tunable fiber Fabry-Perot (Fiber Fabry-Perot, FFP) filter, in particular to a tunable fiber Fabry-Perot (Fiber Fabry-Perot, FFP) filter phase-frequency characteristic New methods and applications of measurement. Background technique [0002] In optical communication, sensing signal demodulation and high-precision spectral analysis, it is necessary to design a controller with tunable FFP filter to scan or track the wavelength of the light source. Since the electrical characteristics of the tuning device PZT (piezoelectric ceramic) in the tunable FFP filter are similar to those of the capacitor, the time constant of the different input signal frequencies will change, so that the output signal of the tunable FFP filter is different from the input signal. time delay. This time delay will cause a change in the phase of multi-beam interference in the FFP filter, resulting in a change in the central wavelength of the tunab...

AI Technical Summary

Problems solved by technology

Although this method does not discuss the phase-frequency characteristics of the filter and its measurement method, but because it has the advantages of high measurement speed, small measurement error and convenient measurement, its measurement principle and method are all important to the phase-frequency characteristic measurement method of the tunable filter. Has a certain reference value

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