A filter for infrared radiation is provided as a photonic cooler coating. The filter for infrared radiation includes a first metal oxide; a second metal oxide; and a metal layer, wherein the first metal oxide layer is provided between the second metal oxide layer and the metal layer.

A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

A device emitting mid-infrared light that comprises a semiconductor substrate of GaSb or closely related material. The device can also comprise epitaxial heterostructures of InAs, GaAs, AlSb, and related alloys forming light emitting structures cascaded by tunnel junctions. Further, the device can comprise light emission from the front, epitaxial side of the substrate.

A device emitting mid-infrared light that comprises a semiconductor substrate of GaSb or closely related material. The device can also comprise epitaxial heterostructures of InAs, GaAs, AlSb, and related alloys forming light emitting structures cascaded by tunnel junctions. Further, the device can comprise light emission from the front, epitaxial side of the substrate.

A chip package structure includes a substrate having a first surface and a second surface being opposite surfaces of the substrate; a housing disposed on the first surface of the substrate and enclosing a chip region; and a chip set disposed in the chip region and electrically connected to the substrate. The chip set includes a first chip and a second chip, and an active surface of the second chip faces the active surface of the first chip.

A chip package structure includes a substrate having a first surface and a second surface being opposite surfaces of the substrate; a housing disposed on the first surface of the substrate and enclosing a chip region; and a chip set disposed in the chip region and electrically connected to the substrate. The chip set includes a first chip and a second chip, and an active surface of the second chip faces the active surface of the first chip.

A cap is mounted to a support substrate, the cap including a cap body and an optical shutter. The cap and support substrate define a housing. An electronic chip is disposed in the housing above the support substrate. A face of the electronic chip supports an optical device that is optically coupled with the optical shutter. The cap body is thermally conductive. Within the housing, a thermally conductive linking structure is coupled in a thermally conductive manner between the cap body and the electronic chip. The thermally conductive linking structure surrounds the electronic chip. A thermal interface material fills a portion of the housing between the thermally conductive linking structure and the cap body.

A cap is mounted to a support substrate, the cap including a cap body and an optical shutter. The cap and support substrate define a housing. An electronic chip is disposed in the housing above the support substrate. A face of the electronic chip supports an optical device that is optically coupled with the optical shutter. The cap body is thermally conductive. Within the housing, a thermally conductive linking structure is coupled in a thermally conductive manner between the cap body and the electronic chip. The thermally conductive linking structure surrounds the electronic chip. A thermal interface material fills a portion of the housing between the thermally conductive linking structure and the cap body.

An electrostatically controlled sensor includes a GaN/AlGaN heterostructure having a 2DEG channel in the GaN layer. Source and drain contacts are electrically coupled to the 2DEG channel through the AlGaN layer. A gate dielectric is formed over the AlGaN layer, and gate electrodes are formed over the gate dielectric, wherein each gate electrode extends substantially entirely between the source and drain contacts, wherein the gate electrodes are separated by one or more gaps (which also extend substantially entirely between the source and drain contacts). Each of the one or more gaps defines a corresponding sensing area between the gate electrodes for receiving an external influence. A bias voltage is applied to the gate electrodes, such that regions of the 2DEG channel below the gate electrodes are completely depleted, and regions of the 2DEG channel below the one or more gaps in the direction from source to drain are partially depleted.