GaAs/AlGaAs single‐mode optical waveguides with low propagation loss and strong optical confinement

Singe‐mode optical waveguides have been fabricated with a saturated bromine water etchant using single‐heterostructure GaAs/AlGaAs epitaxial material, with propagation losses as low as 0.6 dB/cm for 1.66 μm deeply etched ribs (Δneff≂2.4) and losses below 0.2 dB/cm for 0.23 μm shallowly etched ribs (Δneff =0.0067), measured at λ=1.5 μm.