Patent ID: 8107508

Claim:
An external cavity laser light source comprising: a substrate; an optical waveguide comprising a passive waveguide layer, a lower clad layer, an active layer, and an upper clad layer that are sequentially stacked on the substrate, the optical waveguide being divided into regions comprising a linear active waveguide region, a bent active waveguide region, a tapered waveguide region, and a window region; and a current blocking layer formed an outside of the active layer to reduce a leakage current, wherein the linear active waveguide region and the bent active waveguide region have a buried heterostructure (BH), and the tapered waveguide region and the window region have a buried ridge stripe (BRS) structure, and wherein the passive waveguide layer has the substantially same width as that of the linear active waveguide region and is provided in the linear active waveguide region, the bent active waveguide region, the tapered waveguide region, and the window region.