| 摘要 |
PURPOSE:To contrive to stabilize the longitudinal modes of laser beam and to accurately control the film thickness of a clad layer by a method wherein the longitudinal modes of an active layer are locked in the longitudinal modes of a photo waveguide layer formed on the active layer and the photo waveguide layer is set at Y'<0.45. CONSTITUTION:A clad layer 4 is formed on an active layer 3. The clad layer 4 consists of an n type AlZ'Gs1-Z'As layer 41, an n type AlZ''Ga1-Z''As layer 42 and an n type AlY'Ga1-Y'As photo waveguide layer (Y'<Z', Y'<Z'', Y<Y', Y'<0.45Z''>0.45) 43, and the layer 43 is formed between the layer 41 and the layer 42. The photo waveguide layer 43 is set at an interval that the layer 43 generates no laser oscillation by the operating current. By this constitution, the longitudinal modes of the active layer 3 can be locked in the longitudinal modes of the photo waveguide layer 43. Accordingly, stabilization of the longitudinal modes of laser beams can be contrived and the film thickness of the clad layer 4 can be accurately controlled. |
