Evanescent-coupled GaInNAsSb in-line fibre photodetectors

The authors report on in-line fibre photodetectors that can measure power transfer in an optical fibre without interruption of the optical beam, showing 80% external quantum efficiency at 1316 nm wavelength. A new type of structure is used that employs GaNAsSb barriers and GalnNAsSb quantum wells grown by molecular beam epitaxy on GaAs substrates at the centre of anti-resonant reflective optical waveguides to detect long wavelength optical signals without fibre interruption.