Low-loss, single-mode GaAs/AlGaAs waveguides with large core thickness

Abstract

Low-loss, single-mode waveguides with a large core thickness have been designed and fabricated in gallium arsenide/aluminium gallium arsenide waveguides. Detailed beam propagation method simulations were carried out to investigate the modal properties of the waveguides and were compared with measured results. For lengths of 2cm, insertion losses of ≤3.5dB were achieved when coupled to conical lensed fibre. This demonstrates a simple method of achieving minimal coupling losses without the need for complex structures such as waveguide tapers. In addition, the propagation loss was measured to have a low value of 0.2±0.09dB/cm.