A photo-detecting apparatus is provided. The photo-detecting apparatus includes a carrier conducting layer having a first surface; an absorption region is doped with a first dopant having a first conductivity type and a first peak doping concentration, wherein the carrier conducting layer is doped with a second dopant having a second conductivity type and a second peak doping concentration, wherein the carrier conducting layer comprises a material different from a material of the absorption region, wherein the carrier conducting layer is in contact with the absorption region to form at least one heterointerface, wherein a ratio between the first peak doping concentration of the absorption region and the second peak doping concentration of the carrier conducting layer is equal to or greater than 10; and a first electrode and a second electrode both formed over the first surface of the carrier conducting layer.

A light-receiving device of an embodiment of the present disclosure includes a photoelectric conversion layer that includes a first compound semiconductor with a first conductivity type and absorbs a wavelength of an infrared region, a first semiconductor layer formed on the photoelectric conversion layer, and an insulation layer formed to surround the photoelectric conversion layer and the first semiconductor layer, the first semiconductor layer having a second conductivity-type region at a middle region excluding a periphery facing the photoelectric conversion layer.

A light-receiving device of an embodiment of the present disclosure includes a photoelectric conversion layer that includes a first compound semiconductor with a first conductivity type and absorbs a wavelength of an infrared region, a first semiconductor layer formed on the photoelectric conversion layer, and an insulation layer formed to surround the photoelectric conversion layer and the first semiconductor layer, the first semiconductor layer having a second conductivity-type region at a middle region excluding a periphery facing the photoelectric conversion layer.

The system can generally have a substrate, a layered structure supported by the substrate, the layered structure including a first layer being of a first material electrically conductive and transparent to said electromagnetic radiation, a second layer being of a second material electrically conductive and having a first photocurrent generation spectrum covering a first band of energy levels, a middle layer of a third material having a second photocurrent generation spectrum covering a second band of the energy levels of the electromagnetic radiation, the second band complementing the first band; the layered structure connected via the first layer and second layer as an electrical component of an electrical circuit of an acquisition module.

Semiconductor Quantum Cascade Lasers (QCLs), in particular mid-IR lasers emitting at wavelengths of about 3-50 μm, are often designed as deep etched buried heterostructure QCLs. The buried heterostructure configuration is favored since the high thermal conductivity of the burying layers, usually of InP, and the low losses guarantee devices high power and high performance. However, if such QCLs are designed for and operated at short wavelengths, a severe disadvantage shows up: the high electric field necessary for such operation drives the operating current partly inside the insulating burying layer. This reduces the current injected into the active region and produces thermal losses, thus degrading performance of the QCL. The invention solves this problem by providing, within the burying layers, effectively designed current blocking or quantum barriers of, e.g. AIAs, InAIAs, InGaAs, InGaAsP, or InGaSb, sandwiched between the usual InP or other burying layers, intrinsic or Fe-doped. These quantum barriers reduce the described negative effect greatly and controllably, resulting in a QCL operating effectively also at short wavelengths and/or in high electric fields.

A planar photodiode including a main layer including an n-doped first region, a p-doped second region, and an intermediate region, and also a p-doped peripheral lateral portion. It also includes a peripheral intermediate portion, made of an alternation of monocrystalline thin layers of silicon-germanium and germanium, located on the first face, and extending between and at a non-zero distance from the doped first region and from the peripheral lateral portion so as to surround the doped first region in a main plane.

A planar photodiode including a main layer including an n-doped first region, a p-doped second region, and an intermediate region, and also a p-doped peripheral lateral portion. It also includes a peripheral intermediate portion, made of an alternation of monocrystalline thin layers of silicon-germanium and germanium, located on the first face, and extending between and at a non-zero distance from the doped first region and from the peripheral lateral portion so as to surround the doped first region in a main plane.

An imaging device that facilitates pooling processing. A pixel region includes a plurality of pooling modules and an output circuit, the pooling module includes a pooling circuit and a comparison module, the pooling circuit includes a plurality of pixels and an arithmetic circuit, and the comparison module includes a plurality of comparison circuits and a determination circuit. The pixel can obtain a first signal through photoelectric conversion, and can multiply the first signal by a given scaling factor to generate a second signal. The pooling circuit adds a plurality of second signals in the arithmetic circuit to generate a third signal, the comparison module compares a plurality of third signals and outputs the largest third signal to the determination circuit, and the determination circuit determines the largest third signal and binarizes it to generate a fourth signal. In the imaging device, the pooling module performs pooling processing in accordance with the number of pixels and outputs data obtained by the pooling processing.

A dual band photodetector includes a first band absorber layer is configured to absorb incident light in a first wavelength spectral band and a second band absorber layer configured to absorb incident light in a second wavelength spectral band. The dual band photodetector further includes an electron-photon blocking (EPB) layer located between the respective layers and includes at least one high band gap layer and at least one intervening layer. The difference in refractive index between the at least one high band gap layer and the at least one intervening layer form a distributed brag reflector (DBR) designed to reflect wavelengths corresponding with radiative recombination photons emitted from at least the first absorber layer to reduce optical crosstalk between the first band absorber layer and the second band absorber layer.

A dual band photodetector includes a first band absorber layer is configured to absorb incident light in a first wavelength spectral band and a second band absorber layer configured to absorb incident light in a second wavelength spectral band. The dual band photodetector further includes an electron-photon blocking (EPB) layer located between the respective layers and includes at least one high band gap layer and at least one intervening layer. The difference in refractive index between the at least one high band gap layer and the at least one intervening layer form a distributed brag reflector (DBR) designed to reflect wavelengths corresponding with radiative recombination photons emitted from at least the first absorber layer to reduce optical crosstalk between the first band absorber layer and the second band absorber layer.