Multiple, isolated strained quantum well semiconductor laser

摘要

An electron beam pumped semiconductor laser which includes a substrate, an optical gain structure provided on the substrate, the optical gain structure being comprised of a plurality of alternating quantum well layers and isolation layers, the quantum well layers being spaced apart from one another by respective, intervening ones of the isolation layers by a sufficient distance to substantially isolate the quantum well layers from one another, and a first reflective layer provided on a first surface of the optical gain structure. With this construction, the quantum well layers are quantum mechanically uncoupled. Further, the optical gain structure has a total thickness which is sufficient to enable the optical gain structure to be coupled to excitation of an electron beam produced by an electron beam pumping device and directed through the first reflective layer and incident upon the optical gain structure. All of the quantum well layers of the optical gain structure are preferably well-matched in terms of their thickness and compositional uniformity, so that each of the quantum well layers effectively functions as an independent optical gain region having a spectral gain region which is substantially coincident with that of all of the other quantum well layers. Preferably, each of the quantum well layers is strained, with each of the strained quantum well layers preferably having a thickness less than their pseudomorphic strain limit thickness. The semiconductor laser preferably further includes a second reflective layer provided on a second surface of the optical gain structure, whereby a laser cavity is provided in the region bounded by the first and second reflective layers, with the first reflective layer serving as the rear mirror and the second reflective layer serving as the front or output mirror of the laser. The first reflective layer is preferably mostly transmissive with respect to the electron beam and mostly reflective with respect to the laser light generated within the laser cavity. The second reflective layer is preferably partially transmissive and partially reflective with respect to the laser light generated within the laser cavity.