Fully encapsulated narrow-band wavelength selective optical fibre coupler

Fully encapsulated single mode all fibre wavelength division multiplexers have been fabricated. Modulation of the wavelength response, cause by differing coupling strengths for orthogonally polarised modes, has been substantially reduced resulting in devices with narrow band separations ( approximately 10 nm) and large operating ranges (>200 nm). Channel extinction ratios of greater than 20 dB being maintained over the whole range.<
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