Abstract: Embodiments of a method of quantum well intermixing (QWI) comprise providing a wafer comprising upper and lower epitaxial layers, which each include barrier layers, and a quantum well layer disposed between the upper and lower epitaxial layers, applying at least one sacrificial layer over the upper epitaxial layer, and forming a QWI enhanced region and a QWI suppressed region by applying a QWI enhancing layer over a portion of the sacrificial layer, wherein the portion under the QWI enhancing layer is the QWI enhanced region, and the other portion is the QWI suppressed region. The method further comprises the steps of applying a QWI suppressing layer over the QWI enhanced region and the QWI suppressed region, and annealing at a temperature sufficient to cause interdiffusion of atoms between the quantum well layer and the barrier layers of the upper epitaxial layer and the lower epitaxial layer.

Abstract: Methods for forming grating profiles in semiconductor laser structures comprise the steps of providing a semiconductor wafer comprising a wafer substrate, an etch stop layer disposed over the wafer substrate, a grating layer disposed over the etch stop layer, an etch mask layer disposed over the grating layer, and a photoresist layer disposed over the etch mask layer, forming a photoresist grating pattern, transferring the photoresist grating pattern into the grating layers via dry etching, and removing the photoresist layer, selectively wet etching the grating layer to form the grating profile in the grating layer. The placement of the grating layer between the etch mask and etch stop layers controls the selective wet etching step. The method also comprises removing the etch mask layer via selective wet etching without altering the grating profile, and regrowing an upper cladding layer to produce the semiconductor laser structure.

Abstract: A method is provided for receiving data at a receiver via a communication channel from a transmitter having at least two transmitter antennas, the method including: receiving (S204) a codebook including an assignment of at least two respective codewords to the at least two transmitter antennas, the assignment being based at least in part on a characteristic of the communication channel; detecting a state of the communication channel by which the receiver can communicate with the transmitter; selecting (S206) at least one desired transmitter antenna from the at least two antennas based at least in part on the detected state of the communication channel; transmitting (S208) to the transmitter a codeword corresponding to the at least one desired transmitter antenna; and receiving (S210) data at the receiver transmitted by the transmitter.

Abstract: Embodiments of a method of quantum well intermixing (QWI) comprise providing a wafer comprising upper and lower epitaxial layers, which each include barrier layers, and a quantum well layer disposed between the upper and lower epitaxial layers, applying at least one sacrificial layer over the upper epitaxial layer, and forming a QWI enhanced region and a QWI suppressed region by applying a QWI enhancing layer over a portion of the sacrificial layer, wherein the portion under the QWI enhancing layer is the QWI enhanced region, and the other portion is the QWI suppressed region. The method further comprises the steps of applying a QWI suppressing layer over the QWI enhanced region and the QWI suppressed region, and annealing at a temperature sufficient to cause interdiffusion of atoms between the quantum well layer and the barrier layers of the upper epitaxial layer and the lower epitaxial layer.