Abstract: Apparatus, systems, and methods relate to use of a time-varying bias for application to an avalanche photodiode. Embodiments include systems and methods of determining an appropriate time-varying bias for application to an avalanche photodiode in linear mode. Avalanche photodiode having appropriate parameters may also be determined. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, systems, and methods relate to use of a time-varying bias for application to an avalanche photodiode. Embodiments include systems and methods of determining an appropriate time-varying bias for application to an avalanche photodiode in linear mode. Avalanche photodiode having appropriate parameters may also be determined. Additional apparatus, systems, and methods are disclosed.

Abstract: A semiconductor device is supported by a substrate with a smaller lattice constant. A metamorphic buffer provides a transition from the smaller lattice constant of the substrate to the larger lattice constant of the semiconductor device. In one application, the semiconductor device has a lattice constant of between approximately 6.1 and 6.35 angstroms, metamorphic buffer layers include Sb (e.g., AlInSb buffer layers), and the substrate has a smaller lattice constant (e.g., Si, InP or GaAs substrates).

Abstract: Symmetric quantum dots are embedded in quantum wells. The symmetry is achieved by using slightly off-axis substrates and/or overpressure during the quantum dot growth. The quantum dot structure can be used in a variety of applications, including semiconductor lasers.

Abstract: Quantum dot active region structures are disclosed. In a preferred embodiment, the distribution in dot size and the sequence of optical transition energy values associated with the quantum confined states of the dots are selected to facilitate forming a continuous optical gain spectrum over an extended wavelength range. In one embodiment, the quantum dots are self-assembled quantum dots with a length-to-width ratio of at least three along the growth plane. In one embodiment, the quantum dots are formed in quantum wells for improved carrier confinement. In other embodiments, the quantum dots are used as the active region in laser devices, including tunable lasers and monolithic multi-wavelength laser arrays.

Abstract: A quantum dot active region is disclosed in which quantum dot layers are formed using a self-assembled growth technique. In one embodiment, growth parameters are selected to control the dot density and dot size distribution to achieve desired optical gain spectrum characteristics. In one embodiment, the distribution in dot size and the sequence of optical transition energy values associated with the quantum confined states of the dots are selected to facilitate forming a continuous optical gain spectrum over an extended wavelength range. In another embodiment, the optical gain is selected to increase the saturated ground state gain for wavelengths of 1260 nanometers and greater. In other embodiments, the quantum dots are used as the active region in laser devices, including tunable lasers and monolithic multi-wavelength laser arrays.

Abstract: Quantum dot active region structures are disclosed. In a preferred embodiment, the distribution in dot size and the sequence of optical transition energy values associated with the quantum confined states of the dots are selected to facilitate forming a continuous optical gain spectrum over an extended wavelength range. In one embodiment, the quantum dots are self-assembled quantum dots with a length-to-width ratio of at least three along the growth plane. In one embodiment, the quantum dots are formed in quantum wells for improved carrier confinement. In other embodiments, the quantum dots are used as the active region in laser devices, including tunable lasers and monolithic multi-wavelength laser arrays.