Adiabatic Higher Order Mode Guidance in Optical Microfibres

Optical fibres with a logarithmic index profile can provide invariant mode field diameters along the fibre taper, which enables adiabatic mode transitions for higher-order mode microfibres. A 2μm-OD microfibre is fabricated with an insertion loss lower than 0.11dB for the LP
₁₁
mode.