Dispersion compensation using mismatched multicavity etalon all-pass filter

In this paper, we propose a novel mismatched multicavity etalon (MME) all-pass filter for fixed-value dispersion compensation and dispersion slope compensation. It is a multicavity Gires-Tournois (GT) etalon filter with unequal cavity lengths between adjacent cavities. A theoretical study is presented. Analytical expressions for the group delay and chromatic dispersion are derived to allow device designs to be made. The simulation results show that nearly linear group delay or quasi-flat chromatic dispersion response can be obtained by suitably choosing the reflectances of the reflectors and the cavity mismatch length. The chromatic dispersions and the bandwidth of the quasi-flat-dispersion band can be tailored by changing the reflectances of the reflectors and the mismatched cavity length. The dispersion slope compensation can be obtained by slightly modulating the reflectances of the reflectors. Increasing the number of cavities can enhance the performance and the design flexibility of the dispersion compensator.