Large core, multimode, chalcogenide glass fibre coupler by side-polishing
A novel method for obtaining a multimode optical coupler in chalcogenide glass fibre is described. The fibres used had a large \(\text{ Ge }_{17}\text{ As }_{18}\text{ Se }_{65}\) core comprising about 74% of the total cross-sectional area with an optical cladding of \(\text{ Ge }_{17}\text{ As }_{18}\text{ Se }_{62}\text{ S }_{3}\). A single arc-shaped U-groove was formed in each of two silicate glass blocks. A length of fibre was embedded into each groove and glued in place. The centre of each fibre length was subsequently side-polished. Finally two such embedded fibres were glued together in close contact to form the coupler, whilst monitoring the coupling ratio at the output.
chalcogenide glass coupler optical fibre