New integrated optical all-pass filters are presented that can be used for
tunable dispersion compensation, dispersion slope compensation, and as buil
ding blocks in tunable bandpass filters. The dispersion slope compensation
capability is demonstrated using ring resonators in Delta = 2% Ge-doped sil
ica planar waveguides. In addition, a tunable four-stage filter with free-s
pectral range (FSR) = 25 GHz, a passband width of 14 GHz (0.56 x FSR), and
D = 1800 ps/nm is reported.