摘要 |
<p>A junction region for the laser diode may be improved to give an increased wavelength tuning range with improved thermal stability. The region has a homojunction structure that modifies the band structure to approximate that found in a type II superlattice. Up to half of the InGaAsP layer that nearest the p-InP region is n-type doped leaving the remainder with the original doping profile. This creates separate potential wells for electrons and holes in different parts of the InGaAsP layer. Also the barrier for electrons, but not for the holes, on the (p-InP)-(I-InGaAsP)-heterojunction may be increased by inserting a blocking layer of InAlAs, which is lattice matched to InP and InGaAsP, on the p-side between the above two materials.</p> |