Polarization-independent SBS-based narrowband filters for high resolution optical spectrum measurement

A polarization-independent optical filter based on SBS with a bandwidth of ∼10 MHz is proposed and experimentally demonstrated. By utilizing a depolarizer, which can reduce the DOP of pump to <5%, a PDG of <1 dB is obtained over 30 nm. Moreover, it can be used for high-resolution spectroscopy and realizes accurate measurement of signals in arbitrary SOP.