Abstract: A tunable semiconductor laser having, in one embodiment, a higher bias voltage end, a lower bias voltage end, and an optically active gain region comprising a band-gap configured to emit light at an emission wavelength that is tunable when an electric field is generated across the optically active gain region by applying a bias voltage thereto, an electron quantum well (QW) layer positioned closer to the higher bias voltage end than the lower voltage bias end, and a hole QW layer positioned closer to the lower bias voltage end than the higher bias voltage end and comprising a type-II band alignment with the electron QW layer such that the band-gap is determined by an energy difference between a ground electron state in the electron QW layer and a ground hole state in the hole QW layer, wherein the emission wavelength is redshifted upon an increase in a bias voltage applied to the optically active gain region.

Abstract: A semiconductor interband laser that includes a first cladding layer formed using a first high-doped semiconductor material having a first refractive index/permittivity and a second cladding layer formed using a second high-doped semiconductor material having a second refractive index/permittivity. The laser also includes a waveguide core having a waveguide core refractive index/permittivity, the waveguide core is positioned between the first and the second cladding layers. The waveguide core including an active region adapted to generate light based on interband transitions. The light being generated defines the lasing wavelength or the lasing frequency. The first refractive index and the second refractive index are lower than the waveguide core refractive index. The first cladding layer and/or the second cladding layers can also be formed using a metal.

Abstract: A semiconductor interband laser that includes a first cladding layer formed using a first high-doped semiconductor material having a first refractive index/permittivity and a second cladding layer formed using a second high-doped semiconductor material having a second refractive index/permittivity. The laser also includes a waveguide core having a waveguide core refractive index/permittivity, the waveguide core is positioned between the first and the second cladding layers. The waveguide core including an active region adapted to generate light based on interband transitions. The light being generated defines the lasing wavelength or the lasing frequency. The first refractive index and the second refractive index are lower than the waveguide core refractive index. The first cladding layer and/or the second cladding layers can also be formed using a metal.

Abstract: A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

Abstract: A tunable semiconductor laser having, in one embodiment, a higher bias voltage end, a lower bias voltage end, and an optically active gain region comprising a band-gap configured to emit light at an emission wavelength that is tunable when an electric field is generated across the optically active gain region by applying a bias voltage thereto, an electron quantum well (QW) layer positioned closer to the higher bias voltage end than the lower voltage bias end, and a hole QW layer positioned closer to the lower bias voltage end than the higher bias voltage end and comprising a type-II band alignment with the electron QW layer such that the band-gap is determined by an energy difference between a ground electron state in the electron QW layer and a ground hole state in the hole QW layer, wherein the emission wavelength is redshifted upon an increase in a bias voltage applied to the optically active gain region.

Abstract: A semiconductor interband laser that includes a first cladding layer formed using a first high-doped semiconductor material having a first refractive index/permittivity and a second cladding layer formed using a second high-doped semiconductor material having a second refractive index/permittivity. The laser also includes a waveguide core having a waveguide core refractive index/permittivity, the waveguide core is positioned between the first and the second cladding layers. The waveguide core including an active region adapted to generate light based on interband transitions. The light being generated defines the lasing wavelength or the lasing frequency. The first refractive index and the second refractive index are lower than the waveguide core refractive index. The first cladding layer and/or the second cladding layers can also be formed using a metal.

Abstract: A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

Abstract: A semiconductor interband laser that includes a first cladding layer formed using a first high-doped semiconductor material having a first refractive index/permittivity and a second cladding layer formed using a second high-doped semiconductor material having a second refractive index/permittivity. The laser also includes a waveguide core having a waveguide core refractive index/permittivity, the waveguide core is positioned between the first and the second cladding layers. The waveguide core including an active region adapted to generate light based on interband transitions. The light being generated defines the lasing wavelength or the lasing frequency. The first refractive index and the second refractive index are lower than the waveguide core refractive index. The first cladding layer and/or the second cladding layers can also be formed using a metal.

Abstract: A low-defect-density crystalline structure comprising a first crystalline material, a layer of second crystalline material epitaxially grown on the first crystalline material, and a layer of third crystalline material epitaxially grown on the second layer such that the second layer is positioned between the first crystalline material and the third crystalline material. The second and third crystalline materials cooperate to form a desirable relationship. The crystalline structures of the second crystalline material and third crystalline material have a higher crystalline compatibility than the first crystalline material and third crystalline material. The layer of second crystalline material is sufficiently thick to form the desirable relationship with the third crystalline material but sufficiently thin for the layer of second crystalline material to be strained. The layer of third crystalline material is grown to a thickness beyond a thickness had the third layer been grown on an unstrained second layer.

Abstract: A low-defect-density crystalline structure comprising a first crystalline material, a layer of second crystalline material epitaxially grown on the first crystalline material, and a layer of third crystalline material epitaxially grown on the second layer such that the second layer is positioned between the first crystalline material and the third crystalline material. The second and third crystalline materials cooperate to form a desirable relationship. The crystalline structures of the second crystalline material and third crystalline material have a higher crystalline compatibility than the first crystalline material and third crystalline material. The layer of second crystalline material is sufficiently thick to form the desirable relationship with the third crystalline material but sufficiently thin for the layer of second crystalline material to be strained. The layer of third crystalline material is grown to a thickness beyond a thickness had the third layer been grown on an unstrained second layer.