Single-mode fiber-optic demultiplexer

A study was made of the properties of fused single-mode biconical couplers fabricated in a high-frequency electric discharge. A multiplexer–demultiplexer was constructed for the first time with an interval of 1.5 nm between the channels, channel isolation of 20 dB, and excess losses of 0.2 dB. Continuous adjustment of the characteristics of this fused demultiplexer was possible.