Just before the deposition with the Er:Al2O3 Lively material, the coupling circuit, i.e., the strip waveguides, the mode changeover tapers and the mode converters have been protected with a 800 nm thick layer of hydrogen silsesquioxane (HSQ, n ~1.45) to avoid their coating with the active content, as revealed in https://johnp652qai2.howeweb.com/profile