Before the deposition in the Er:Al2O3 active materials, the coupling circuit, i.e., the strip waveguides, the mode transition tapers as well as the method converters had been coated by using a 800 nm thick layer of hydrogen silsesquioxane (HSQ, n ~1.forty five) to circumvent their coating with the active product, https://cicilg207zhn3.nizarblog.com/profile