This invention provides an optical
waveguide amplifier and a method for fabricating it. The optical
waveguide amplifier includes a substrate layer, an insulating layer, a passive
waveguide layer, and multiple doped
layers. The insulating
layers are stacked on the substrate layer. The passive waveguide layer and the multiple doped
layers are stacked on the insulating layer. An m-layer doped layer is disposed above the passive waveguide layer, and an n-layer doped layer is disposed below it, where m and n are integers, m+n≥2, and m≥0, n≥0. The multiple doped layers are doped with various rare-earth ions. Compared to
fiber amplifiers doped with rare-earth elements, the optical
waveguide amplifier in this embodiment is smaller, which simplifies the device structure, reduces device size, and lowers costs. Compared to existing on-
chip optical waveguide amplifiers, the optical
waveguide amplifier in this embodiment can be doped with various rare-earth ions, enabling the amplification of
broadband signals and broadening its applicability.