In fabricating a semiconductor laser producing light with a wavelength of 770 to 810 nm, impurities are introduced into an MQW active layer near a light emitting facet of the laser to form a disordered region constituting a window layer. Pump light is applied to the window layer to generate photoluminescence whose wavelength .lamda. dpl (nm) is measured. A blue shift amount .lamda. bl (nm) is defined as the difference between the wavelength .lamda. apl (nm) 0f photoluminescence generated by application of pump light to the active layer on the one hand, and the wavelength .lamda. dpl (nm) of photoluminescence from the window layer under pump light irradiation on the other hand. The blue shift amount .lamda. bl is referenced during the fabrication process in order to predict catastrophic optical damage levels of semiconductor lasers.

 
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> Optical head and optical disc apparatus for focusing a collimated laser beam

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