| 摘要 |
<p>A semiconductor laser (100) has an optical cavity (107) comprising and active layer (102) disposed between an n-side barrier layer (103) and a p-side barrier layer (104). The active layer (102) comprises alternating layers (113, 1 14) of a first and second material, and the n-side barrier layer (103) and p-side barrier layer (104) each comprise alternating layers (115, 116) of the first material and a third material. The materials are selected such that the layers (114, 116) of the second and third materials form quantum wells between the layers (113, 115) of the first material. A band gap Eg of the second material is arranged such that a proportion of electrons and holes that recombine across the band gap Eg recombine to emit photons at the lasing wavelength, the proportion decreasing with increasing temperature of the optical cavity (107). A band gap Ec of the third material is arranged such that a ratio of electrons and holes that recombine across the band gap Eg of the second material to electrons and holes that recombine across the band gap Ec of the third material increases with increasing temperature of the optical cavity (107). Over a range of temperatures at which the semiconductor laser (100) is intended to operate, the increasing ratio compensates for the decreasing proportion so as to reduce change with temperature of the optical cavity (107) in the rate at which electrons and holes recombine across the band gap Eg of the second material to emit photons at the lasing wavelength.</p> |
