New structure of tunable wavelength-selective filters with a liquid crystal for FDM systems

To decrease the bandwidth of liquid-crystal Fabry-Perot interferometers (LC-FPIs), LC-FPIs having a double-layer cavity were devised where the intracavity consists of the LC layer and a glass layer. This filter is shown to have a very narrow bandwidth (full width at half maximum <10 GHz), low loss (4 dB), and a large tunability (9 nm). It is also shown to have the potential to select over 50 channels for FDM (frequency division multiplexing) systems.<
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