A transmission circuit includes a photocoupler, a conductive/non-conductive state of which is controlled in accordance with data to be transmitted to a communication device. A reception circuit includes a photocoupler, a conductive/non-conductive state of which is controlled in accordance with the conductive/non-conductive state of the transmission path. A transmission circuit includes a photocoupler, a conductive/non-conductive state of which is controlled in accordance with data to be transmitted to a communication device. A reception circuit includes a photocoupler, a conductive/non-conductive state of which is controlled in accordance with the conductive/non-conductive state of the transmission path. The photocoupler is included in the transmission path. The photocoupler and the photocoupler are in opposite conductive/non-conductive states.

An optoelectronic device and method of making the same. The device comprising: a substrate; an epitaxial crystalline cladding layer, on top of the substrate; and an optically active region, above the epitaxial crystalline cladding layer; wherein the epitaxial crystalline cladding layer has a refractive index which is less than a refractive index of the optically active region, such that the optical power of the optoelectronic device is confined to the optically active region.

Disclosed is an active photonic device having a Darlington configuration with a substrate and a collector layer that is over the substrate. The collector layer includes an inner collector region. An outer collector region substantially surrounds the inner collector region and is spaced apart from the inner collector region. A base layer is over the collector layer. A first outer base region and a second outer base region substantially surround the inner base region and are spaced apart from the inner base region and each other. An emitter layer is over the base layer. The emitter layer includes an inner emitter region that is ring-shaped and resides over and extends substantially around an outer periphery of the inner base region. A first outer emitter region and a second outer emitter region substantially surround the inner emitter region and are spaced apart from the inner emitter region and each other.

A method and system for optoelectronic receivers utilizing waveguide heterojunction phototransistors (HPTs) integrated in a wafer are disclosed and may include receiving optical signals via optical fibers operably coupled to a top surface of the chip. Electrical signals may be generated utilizing HPTs that detect the optical signals. The electrical signals may be amplified via voltage amplifiers, or transimpedance amplifiers, the outputs of which may be utilized to bias the HPTs by a feedback network. The optical signals may be coupled into opposite ends of the HPTs. A collector of the HPTs may comprise a silicon layer and a germanium layer, a base may comprise a silicon germanium alloy with germanium composition ranging from 70% to 100%, and an emitter including crystalline or poly Si or SiGe. The optical signals may be demodulated by communicating a mixer signal to a base terminal of the HPTs.

In described examples, an integrated circuit includes a leadframe structure, which includes electrical conductors. A first coil structure is electrically connected to a first pair of the electrical conductors of the leadframe structure. The first coil structure is partially formed on a semiconductor die structure. A second coil structure is electrically connected to a second pair of the electrical conductors of the leadframe structure. The second coil structure is partially formed on the semiconductor die structure. A molded package structure encloses portions of the leadframe structure. The molded package structure exposes portions of the first and second pairs of the electrical conductors to allow external connection to the first and second coil structures. The molded package structure includes a cavity to magnetically couple portions of the first and second coil structures.

An on-chip mode converter-based silicon-germanium photoelectric detection apparatus comprises an insulating substrate, an optical coupler, an on-chip mode converter and a multi-mode silicon-germanium photoelectric detector. The optical coupler, the converter and the photoelectric detector are sequentially connected and all fixed on silicon wafers of the insulating substrate. An incident fundamental mode optical signal is transmitted to the optical coupler through a single-mode fiber, enters the converter via the optical coupled. The converter converts the fundamental mode optical signal into a multi-mode optical field and enters the photoelectric detector, which converts the multi-mode optical field into an electrical signal. Heavily germanium-doped region are located in areas with relatively weak distributed light intensity of the multi-mode optical field. The absorption loss of the heavily germanium-doped region and third through-holes on the optical field is dramatically reduced and the responsiveness of the apparatus can be improved effectively.

The present invention relates to a semiconductor laser for use in an optical module for measuring distances and/or movements, using the self-mixing effect. The semiconductor laser comprises a layer structure including an active region (3) embedded between two layer sequences (1, 2) and further comprises a photodetector arranged to measure an intensity of an optical field resonating in said laser. The photodetector is a phototransistor composed of an emitter layer (e), a collector layer (c) and a base layer (b), each of which being a bulk layer and forming part of one of said layer sequences (1, 2). With the proposed semiconductor laser an optical module based on this laser can be manufactured more easily, at lower costs and in a smaller size than known modules.

Disclosed is an active photonic device having a Darlington configuration with a substrate and a collector layer that is over the substrate. The collector layer includes an inner collector region. An outer collector region substantially surrounds the inner collector region and is spaced apart from the inner collector region. A base layer is over the collector layer. A first outer base region and a second outer base region substantially surround the inner base region and are spaced apart from the inner base region and each other. An emitter layer is over the base layer. The emitter layer includes an inner emitter region that is ring-shaped and resides over and extends substantially around an outer periphery of the inner base region. A first outer emitter region and a second outer emitter region substantially surround the inner emitter region and are spaced apart from the inner emitter region and each other.

An improvement is achieved in the performance of a semiconductor device. A semiconductor device includes an n.sup.-type semiconductor region formed in a p-type well, an n-type semiconductor region formed closer to a main surface of a semiconductor substrate than the n.sup.-type semiconductor region, and a p.sup.-type semiconductor region formed between the n.sup.-type semiconductor region and the n-type semiconductor region. A net impurity concentration in the n.sup.-type semiconductor region is lower than a net impurity concentration in the n-type semiconductor region. A net impurity concentration in the p.sup.-type semiconductor region is lower than a net impurity concentration in the p-type well.

Disclosed herein is a phototransistor (PT) comprising an emitter, a collector and a floating base; wherein the floating base, a p-n junction between the emitter and base (E-B junction) and a p-n junction between the base and the collector (B-C junction) are collectively in direct physical contact only with and completely encapsulated only by the emitter, the collector, and a section of a dielectric. Under an operating condition of the PT, a DC current density averaged over the E-B junction or a DC current density averaged over the B-C junction may be at least 100 times of a DC current density averaged over an opto-electronically active region of the PT. A sum of a capacitance of the E-B junction and a capacitance of the B-C junction may be less than 1 fF.