NARROW-BAND, WAVELENGTH-DIVISION MULTIPLEXERS USING BIREFRINGENT OPTICAL FIBER

In-line wavelength-division demultiplexers (WDMs) based on a polarisation separation technique using birefringent optical fibre are presented. The theory of the devices is developed and the factors affecting their performance are discussed. Devices capable of demultiplexing wavelengths separated by approximately 30 GHz and approximately 200 GHz, respectively, are demonstrated. Practical limitations on maximum and minimum wavelength separations are discussed. The major factor affecting stability is identified as temperature, and techniques to minimise this effect are presented. The technique is shown to be capable of separating the pump and the frequency downshifted stimulated Brillouin scattered light generated using a fibre optic ring resonator.