A broadband, electrically controlled polarization- independent intensity modulator (PIM) based on a Sagnac inter- ferometer is presented. Influences from asymmetric modulation and traveling wave effects are analyzed and methods to elim- inate these effects are proposed. Compared to Mach-Zehnder interferometer-based modulators, this modulator is independent of the input polarization state and less sensitive to ambient per- turbations due to its reciprocity property. A prototype modulator operating at 1 and 2.488 Gb/s modulation rates is demonstrated.

A high-speed, polarization independent, electrooptic tunable filter was built using a birefringence modulator within a Sagnac interferometer. Switching times less than 0.5 ns were achieved in our experiment for this filter. Application in high- speed wavelength routing was also demonstrated.