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: A semiconductor laser having an angled facet is provided. The semiconductor laser includes a first distributed Bragg reflector (DBR). The laser further includes an active region coupled to the first DBR, wherein the active region comprises a highly reflective facet and a partially reflective facet, and a second DBR coupled to the active region. The highly reflective facet, the partially reflective facet, the first DBR, and the second DBR form a laser cavity having a shape that is not rectangular. An angled facet emitter enables, for example, single vertical transverse mode operation of optically thick epitaxial gain regions.

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: 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: A quantum dot vertical cavity surface-emitting laser has a low threshold gain. Top and bottom mirrors have a low mirror loss, with at least one of the mirrors being laterally oxidized to form semiconductor/oxide mirror pairs. In one embodiment, mode control layers reduce the optical field intensity in contact layers, reducing optical absorption. In one embodiment, delamination features are included to inhibit the tendency of laterally oxidized mirrors from delaminating.

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 vertical cavity surface-emitting laser has a low threshold gain. Top and bottom mirrors have a low mirror loss, with at least one of the mirrors being laterally oxidized to form semiconductor/oxide mirror pairs. In one embodiment, mode control layers reduce the optical field intensity in contact layers, reducing optical absorption. In one embodiment, delamination features are included to inhibit the tendency of laterally oxidized mirrors from delaminating.

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.