Abstract: An apparatus includes a substrate and a plurality of DNA oligomers in contact with a top surface of the substrate. The substrate is a polar ferroelectric or a polar compound semiconductor.

Abstract: An apparatus comprising a structure comprising a group III-nitride and a junction between n-type and p-type group III-nitride therein, the structure having a pyramidal shape or a wedge shape.

Abstract: A method of manufacturing an apparatus, comprising forming a light-emitting crystalline structure. Forming the light-emitting crystalline structure includes forming a first barrier region on a substrate, the first barrier region having one or more inclined surfaces relative to a planar surface of the substrate. Forming the light-emitting crystalline structure also includes forming a second barrier region over the first barrier region, to form a junction at the inclined surfaces, wherein the first barrier region comprises one of an n-type or p-type semiconductor crystal, and the second barrier region comprises the other of the n-type or p-type semiconductor crystal.

Abstract: A device 100 comprising a substrate 115 having crystal-support-structures 110 thereon, and a III-V crystal 210. The III-V crystal is on a single contact region 140 of one of the crystal-support-structures. An area of the contact region is no more than about 50 percent of a surface area 320 of the III-V crystal.

Abstract: A device 100 comprising a substrate 115 having crystal-support-structures 110 thereon, and a III-V crystal 210. The III-V crystal is on a single contact region 140 of one of the crystal-support-structures. An area of the contact region is no more than about 50 percent of a surface area 320 of the III-V crystal.

Abstract: A device 100 comprising a substrate 115 having crystal-support-structures 110 thereon, and a III-V crystal 210. The III-V crystal is on a single contact region 140 of one of the crystal-support-structures. An area of the contact region is no more than about 50 percent of a surface area 320 of the III-V crystal.

Abstract: An apparatus comprising a structure comprising a group III-nitride and a junction between n-type and p-type group III-nitride therein, the structure having a pyramidal shape or a wedge shape.

Abstract: An apparatus includes an optical waveguide and an optical filter positioned to receive light from the optical waveguide. The optical waveguide includes a sequence of alternating first and second stripes. The sequence runs along a propagation direction in the optical waveguide. The first and second stripes are formed of different polarization states of a group III-nitride semiconductor. The optical filter removes light of a preselected frequency.

Abstract: An apparatus includes a crystalline substrate, a layer of a first group III-nitride located on a planar surface of the substrate, and a layer of a second group III-nitride located over the layer of the first group III-nitride. The first and second group III-nitrides have different alloy compositions. The layer of second group III-nitride may have a pattern of columnar holes or trenches therein. The apparatus may include a plurality of pyramidal field-emitters that include the second group III-nitride.

Abstract: A fabrication method produces a mechanically patterned layer of group III-nitride. The method includes providing a crystalline substrate and forming a first layer of a first group III-nitride on a planar surface of the substrate. The first layer has a single polarity and also has a pattern of holes or trenches that expose a portion of the substrate. The method includes then, epitaxially growing a second layer of a second group III-nitride over the first layer and the exposed portion of substrate. The first and second group III-nitrides have different alloy compositions. The method also includes subjecting the second layer to an aqueous solution of base to mechanically pattern the second layer.

Abstract: A quantum well structure is provided that includes two or more quantum well layers coupled by at least one barrier layer such that at least one of a piezo-electric field and a pyro-electric field is produced. The quantum well structure is sufficiently doped to cause a Fermi energy to be located between ground states and excited states of the coupled quantum well layers. The quantum well structure can be incorporated into a layered semiconductor to form optical devices such as a laser or optical amplifier.

Abstract: A fabrication method produces a mechanically patterned layer of group III-nitride. The method includes providing a crystalline substrate and forming a first layer of a first group III-nitride on a planar surface of the substrate. The first layer has a single polarity and also has a pattern of holes or trenches that expose a portion of the substrate. The method includes then, epitaxially growing a second layer of a second group III-nitride over the first layer and the exposed portion of substrate. The first and second group III-nitrides have different alloy compositions. The method also includes subjecting the second layer to an aqueous solution of base to mechanically pattern the second layer.

Abstract: An optical device includes a stack of at least two different intersubband (ISB) optical sub-devices in which the gain/loss profiles of the individual ISB sub-devices are mutually adapted, or engineered, so as to generate a predetermined overall function for the combination. We define this combination device as being heterogeneous since not all of the individual ISB sub-devices are identical to one another. Illustratively, the parameters of each individual ISB sub-device that might be subject to this engineering process include: the peak energy of the ISB optical transitions (emission or absorption) associated with each RT region, the position of each sub-device in the stack; the oscillator strengths of these ISB transitions; the energy bandwidth of each transition; and the total length of the RT and I/R regions of each ISB sub-device.

Abstract: An apparatus includes an optical waveguide and an optical filter positioned to receive light from the optical waveguide. The optical waveguide includes a sequence of alternating first and second stripes. The sequence runs along a propagation direction in the optical waveguide. The first and second stripes are formed of different polarization states of a group III-nitride semiconductor. The optical filter removes light of a preselected frequency.

Abstract: A quantum well structure is provided that includes two or more quantum well layers coupled by at least one barrier layer such that at least one of a piezo-electric field and a pyro-electric field is produced. The quantum well structure is sufficiently doped to cause a Fermi energy to be located between ground states and excited states of the coupled quantum well layers. The quantum well structure can be incorporated into a layered semiconductor to form optical devices such as a laser or optical amplifier.

Abstract: An optical device includes a stack of at least two different intersubband (ISB) optical sub-devices in which the gain/loss profiles of the individual ISB sub-devices are mutually adapted, or engineered, so as to generate a predetermined overall function for the combination. We define this combination device as being heterogeneous since not all of the individual ISB sub-devices are identical to one another. Illustratively, the parameters of each individual ISB sub-device that might be subject to this engineering process include: the peak energy of the ISB optical transitions (emission or absorption) associated with each RT region, the position of each sub-device in the stack; the oscillator strengths of these ISB transitions; the energy bandwidth of each transition; and the total length of the RT and I/R regions of each ISB sub-device.

Abstract: An intersubband (ISB) optical device comprises first quantum well (QW) interior regions having upper and lower energy states between which ISB transitions take place; and superlattice (SL) barrier regions interposed between the first QW interior regions. The SL barrier regions include second barriers and second QW interior regions, with the second QW interior regions being interposed between the second barrier regions. The first QW interior regions and the SL barrier regions are configured to produce an energy gap between the upper and lower states that is larger than the energy of a 1.7 &mgr;m wavelength photon. In accordance with another aspect of our invention, an intersubband optical device comprises a core region that includes a multiplicity of repeat units (RUs), each RU including a first barrier region and a QW active region disposed adjacent thereto, characterized in that (1) each of the QWs has upper and lower energy states separated by an energy greater than that of a 1.