The application provides a low-loss multilayer
coupling ridge-shaped optical
waveguide laser chip and a preparation method, relates to the technical field of
laser chips, and comprises a layered gradient interface
ridge-shaped core, a distributed
coupling ring cavity, a lateral compensation
ridge-shaped shell and an integrated feedback ridge-shaped terminal. The bottom layer of the layered gradient interface ridge-shaped core is a
silicon-based ridge-shaped layer with a thickness of 180-220 nm, the top of the
silicon-based ridge-shaped layer is provided with a gradient
refractive index transition zone with a thickness of 40-60 nm, and the top of the gradient
refractive index transition zone is provided with a
gain material layer with a thickness of 280-320 nm. The application sets the gradient
refractive index transition zone in the layered gradient interface ridge-shaped core, realizes mode field smooth matching between the
silicon-based ridge-shaped layer and the
gain material layer, reduces the interface
reflection loss to below 0.08 dB, and thus effectively solves the problems of mode mismatch and high
reflection loss (usually above 0.5-1 dB) caused by refractive index mismatch during the integration of heterogeneous materials in the prior art.