A light detection device includes a photo detector and a circuit board connected to the photo detector by conductive connection parts. In this light detection device, the photo detector includes a substrate, a semiconductor layer provided on one surface of the substrate, a first groove dividing the semiconductor layer into sections for respective pixels, and first electrodes provided on the semiconductor layer and serving as the pixels. Each of the conductive connection part contains indium. Each of the first electrode includes a Ti layer and a Pt layer stacked in this order on the semiconductor layer, and the conductive connection parts are provided on the Pt layers of the first electrodes.

An optical device for detecting a first chemical species and a second chemical species contained in a specimen, which includes: a first optical sensor, which may be optically coupled to an optical source through the specimen and is sensitive to radiation having a wavelength comprised in a first range of wavelengths; and a second optical sensor, which may be optically coupled to the optical source through the specimen and is sensitive to radiation having a wavelength comprised in a second range of wavelengths, different from the first range of wavelengths.

A light-receiving device includes at least one pixel. The at least one pixel includes a first electrode; a second electrode; and a photoelectric conversion layer between the first electrode and the second electrode. The photoelectric conversion layer is configured to convert incident infrared light into electric charge. The photoelectric conversion layer has a first section and a second section. The first section is closer to the first electrode than the second section, and the second section is closer to the second electrode than the first section. At least one of the first section and the second section have a plurality of surfaces.

A semiconductor light receiving element of back-illuminated type comprises a light absorbing portion formed in the vicinity of the main surface of the semiconductor substrate transparent to the incident light, and a first convex lens portion larger than the light absorbing portion and having a radius of curvature R1 formed on a back surface of the semiconductor substrate, a second convex lens portion smaller than the light absorbing portion and having a radius of curvature R2 smaller than the radius of curvature R1; the second convex lens portion formed on the first convex lens portion and having a focal point between the second convex lens portion and the light absorbing portion; light incident on the second convex lens portion is diffused from the focal point toward the light absorbing portion.

Various embodiments of the present disclosure are directed towards an image sensor having a photodetector disposed in a semiconductor substrate. The photodetector comprises a first doped region having a first doping type. A deep well region is disposed within the semiconductor substrate, where the deep well region extends from a back-side surface of the semiconductor substrate to a top surface of the first doped region. A second doped region is disposed within the semiconductor substrate and abuts the first doped region. The second doped region and the deep well region comprise a first dopant having a second doping type opposite the first doping type, where the first dopant comprises gallium.

Diffusion-based and ion implantation-based methods are provided for fabricating planar photodetectors. The methods may be used to fabricate planar photodetectors comprising type II superlattice absorber layers but without mesa structures. The fabricated planar photodetectors exhibit high quantum efficiencies, low dark current densities, and high specific detectivities as compared to photodetectors having mesa structures.

A photodiode has an absorption layer and a cap layer operatively connected to the absorption layer. A pixel is formed in the cap layer and extends into the absorption layer to receive charge generated from photons therefrom. The pixel defines an annular diffused area to reduce dark current and capacitance. A photodetector includes the photodiode. The photodiode includes an array of pixels formed in the cap layer. At least one of the pixels extends into the absorption layer to receive charge generated from photons therefrom. At least one of the pixels defines an annular diffused area to reduce dark current and capacitance.

Systems and methods for thermal radiation detection utilizing a thermal radiation detection system are provided. The thermal radiation detection system includes one or more Indium Antimonide (InSb)-based photodiode infrared detectors and a temperature sensing circuit. The temperature sensing circuit is configured to generate signals correlated to the temperatures of one or more of the plurality of infrared sensor elements. The thermal radiation detection system also includes a signal processing circuit.

A connector that provides alignment of an optical fiber to a photonic device. The connector has a threaded sleeve, a ferrule cavity, an aperture in optical communication with the ferrule cavity and having a center that is substantially aligned with a center of the ferrule cavity and a device cavity that is configured to receive the photonic device and further in optical communication with the ferrule cavity via the aperture.

Provided are a semiconductor photodiode which achieves a higher response rate in a state in which light receiving sensitivity is maintained. The semiconductor photodiode includes a p-type semiconductor contact layer, an n-type semiconductor contact layer, and a light absorption layer. The light absorption layer includes a first semiconductor absorption layer having a thickness Wd and a p-type second semiconductor absorption layer having a thickness Wp. The first semiconductor absorption layer and the second absorption layer are made of the same composition. The first semiconductor absorption layer is depleted, and the second semiconductor absorption layer maintains an electric charge neutral condition except for a region near an interface with the first semiconductor absorption layer. A relationship between the thickness Wd and the thickness Wp satisfies 0.47Wp/(Wp+Wd)0.9.