Method of fabricating semiconductor laser

A semiconductor laser device fabricating method including the steps of:

• firstly forming a first clad layer of a first conductivity type, an active layer of a quantum well structure, and a first second-clad layer of a second conductivity type successively on a semiconductor substrate of the first conductivity type;
• secondly forming on a surface of the first second-clad layer a mask pattern for impurity implantation having an opening in a region where a resonator facet of a semiconductor laser device is expected to be formed;
• thirdly disordering the active layer near the resonator facet by introducing impurities with the mask pattern for introducing impurity used as a mask;
• fourthly applying pumped light to the disordered region to generate photo luminescence therefrom, and measuring a wavelength of the photo luminescence as a basis for predicting a level of COD degradation;
• fifthly forming a second second-clad layer of the second conductivity type on the surface of said first second-clad layer after removing the mask pattern;
• sixthly forming on a surface of the second second-clad layer a stripe-shaped mask pattern in a manner opposed to the disordered active layer across the first and the second second-clad layer, the stripe-shaped mask pattern extending in a resonator lengthwise direction;
• and
• seventhly forming an optical waveguide including the second second-clad layer with the stripe-shaped mask pattern used as a mask.