Wavelength- and polarization-selective fused single-mode couplers

Analytical results are presented that describe the characteristics of fused single-mode tapered couplers. The influence of coupler geometry on polarization splitting and spectral selectivity is investigated. A selective fused coupler has been made that exhibits a channel separation of Deltalambda = 0.6 nm, an insertion loss of 1 dB, and an extinction ratio of 20 dB. Polarization selectivity of 20 dB has also been achieved.