Electronically tunable liquid-crystal-etalon filter for high-density WDM systems

A 1.5- mu m high-density wavelength-division-multiplexed (HD-WDM) system experiment is demonstrated using a novel Fabry-Perot etalon filter with a liquid-crystal electrical tuning element. The filter has a narrow passband (0.4 nm) and is continuously tunable over a wavelength range of >60 nm with a drive voltage from 1 to 5 V. Bit-error-rate measurements with an 8-channel (1539-1556 nm), 622 Mb/s WDM system confirms that the crosstalk penalty is negligible for an optical channel spacing of 2 nm.<
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