| 摘要 |
PURPOSE:To match a grating constant, and to lengthen the life of the device by a method wherein double hetero structure is formed by an active layer by AlxGa1-x AsyP1-y and a clad layer on a GaAs substrate, and the ratios of mixed crystals x, y are selected according to predetermined manners. CONSTITUTION:Stress due to the mismatch of the grating constant increases in the active layer with short wavlengths in the GaAs-Ga1-xAlxAs group double hetero structure, and the life is shortened. Compressive stress increases extremely when the ratio of the mixed crystal x is 0.1 or higher. Accordingly, a range of x=0.07-0.45 and y=0.92-0.99 is used as the active layer and a range of x= 0.15-0.95 and y=0.90-0.98 as the clad layer, and x and y are selected from relationship with a band gap. According to this constitution, stress applied to the active layer of a double hetero epitaxial crystal is reduced remarkably in an extent which cannot be measured, a long life can be attained, the device oscillates in the low threshold and even 700nm wavelength can be obtained. |
