Efficient, narrowband LP ₀₁ ↔LP ₀₂ mode convertors fabricated in photosensitive fibre: spectral response

Abstract

LP01 ↔ LP02 mode convertors have been fabricated by photoinducing index gratings within the fibre core by means of internally or externally applied light fields. The mode convertors have conversion efficiencies of over 75% and simple spectral response curves with one or two peaks. The mode conversion linewidths range from 0.2 to 10 nm.