| 摘要 |
<p>A vertical cavity surface emitting laser (VCSEL) includes a bottom mirror stack disposed above a semiconductor substrate, an optical cavity including an active region disposed above the bottom mirror stack, and a top mirror stack disposed above the optical cavity. A tunnel junction interface between an n-doped layer of GaAs and a p-doped layer of GaAs for converting electrons to holes is incorporated in the optical cavity or in the period of either of the mirror stacks adjacent the optical cavity. The tunnel junction interface effectively converts n carriers to p carriers, which eliminates the need for a p-type contact. As a result, the VCSEL is able to include a second n-type contact, rather than the p-type contact suggested by conventional techniques, and a thin p-doped GaAs layer. The advantages of having a second n-type contact rather than a p-type contact include a lower electrical resistance and lower optical loss for the VCSEL. When the invention is embodied in a VCSEL with an intracavity contact, one of the mirrors can be undoped. This futher reduces optical loss for the VCSEL. The VCSEL can be electrically pumped using first and second contacts to n-material portions of the VCSEL to emit coherent electromagnetic radiation having a wavelength in a range from 1250 nm to 1650 nm.</p> |
