Abstract: A radio-frequency amplifier for a cable network includes a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of the cable network and a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of the cable network. An out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to the cable receiver of the cable network and a notch filter configured to reject the amplified digitally protected video signal having the frequency in the range between 70 MHz and 130 MHz from being amplified by the return amplifier.

Abstract: An apparatus for implementing soft duplex operation of a communications network that transmits downstream signals from a service provider to a subscriber and upstream signals from the subscriber to the service provider. The apparatus may include a pair of opposed triplexers defining a first signal path through a first amplifier and a second signal path through a second amplifier. The apparatus may also include at least one switch that selectively alternates a mid0band signal between an upstream signal and a downstream signal.

Abstract: A transmitting and/or receiving system for cable networks.

Abstract: An amplification system for amplifying a service of a cable television network that includes a first amplifier receiving the service and providing a first output signal having a first frequency band with a first maximum downstream frequency to a first customer and a second amplifier. The amplification system includes the second amplifier receiving the first output signal and providing a second output signal having a second frequency band with a second maximum downstream frequency to a second customer, wherein the second maximum downstream frequency is less than the first maximum downstream frequency.

Abstract: A radio-frequency amplifier for a cable network includes a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of the cable network and a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of the cable network. An out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to the cable receiver of the cable network and a notch filter configured to reject the amplified digitally protected video signal having the frequency in the range between 70 MHz and 130 MHz from being amplified by the return amplifier.

Abstract: A transmitting and/or receiving system for cable networks.

Abstract: VCSELs have a substrate, first and second electrical contacts (ECs), and an optical resonator (OR), having first and second distributed Bragg reflectors (DBRs) and an active layer between the DBRs. The first DBR is between the substrate and the active layer. One of the DBRs has: first and second parts, having different conductivity types, and each with a pair of layers with different refractive indices. A tunnel junction (TJ) is between the parts. The ECs are for electrically pumping the OR such that the TJ is reversely biased during operation of the VCSEL. Either the first DBR includes the parts, having a relative thickness of the second part to a total thickness of the first and second parts between 0.1-0.8, or the second DBR has the parts, the second part being on the TJ facing away from the active layer, and the relative thickness being between 0.15-0.6.

Abstract: The invention describes a light emitting semiconductor device (100) comprising a substrate (120), a light emitting layer structure (155) and an AlGaAs getter layer (190) for reducing an impurity in the light emitting layer structure (155), the light emitting layer structure (155) comprising an active layer (140) and layers of varying Aluminum content, wherein the growth conditions of the layers of the light emitting layer structure (155) comprising Aluminum are different in comparison to the growth conditions of the AlGaAs getter layer (190). The AlGaAs getter layer (190) enables a reduction of the concentration of impurities like Sulfur etc. in the gas phase of a deposition equipment or growth reactor. The reduction of such impurities reduces the probability of incorporation of the impurities in the light emitting layer structure (155) which may affect the lifetime of the light emitting semiconductor device (100).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention describes a light emitting semiconductor device (100) comprising a substrate (120), a light emitting layer structure (155) and an AlGaAs getter layer (190) for reducing an impurity in the light emitting layer structure (155), the light emitting layer structure (155) comprising an active layer (140) and layers of varying Aluminum content, wherein the growth conditions of the layers of the light emitting layer structure (155) comprising Aluminum are different in comparison to the growth conditions of the AlGaAs getter layer (190). The AlGaAs getter layer (190) enables a reduction of the concentration of impurities like Sulfur etc. in the gas phase of a deposition equipment or growth reactor. The reduction of such impurities reduces the probability of incorporation of the impurities in the light emitting layer structure (155) which may affect the lifetime of the light emitting semiconductor device (100).

Abstract: 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.

Abstract: A sensor module (1) for measuring the distance to a target and/or the velocity of the target (50), the sensor module (1) comprising at least one laser source (100), at least one detector (200) being adapted to detect modulated laser light and at least one control element the control element (400) being adapted to vary the focus point of the laser light and/or the intensity of the laser light and/or the direction of the laser light. The control of the laser light emitted by the laser source (100) either by active optical devices as variable focus lenses or controllable attenuators or passive optical elements in combination with arrays of laser sources (100) and detectors (200) enable flexible and robust sensor modules.

Abstract: The present invention relates to a vertical cavity surface emitting laser device comprising a VCSEL with a monolithically integrated photodiode. The photodiode (2) is formed of a layer sequence of a first n-doped region (6), a p-doped region (7), an intrinsic region (8) and a second n-doped region (9) of a semiconductor material. The photodiode (2) and the laser share a common electrode, which is realized as an Ohmic n-contact (10) at said first n-doped region (6). The proposed device allows less complex manufacturing, resulting in lower manufacturing costs.

Abstract: A controller for controlling the power of a laser that is used in determining the motion of an object includes a power source that is arranged to supply power pulses to the laser in response to a controller signal. The controller controls the generation of pulses during periods in which a reliable result can be obtained, by detecting the laser radiation that has interacted with pulses reflected from the object, in order to conserve power consumption. Further the power pulses include a heating pulse portion, which serves to stabilize the temperature of the laser and calibrate the laser so that a known lasing wavelength is generated.

Abstract: A laser self-mixing measuring device is provided, comprising a laser with a laser cavity and a surface arranged along the optical path of the laser beam which redirects incident laser light back into the laser cavity. The surface comprises a periodic structure which diffracts the laser light into partial beams.

Abstract: The invention relates to an optical sensor module (1) for a measuring device. Said module comprises at least one optical sensor (2) including a diode laser (3) having a laser cavity for generating a measuring beam, the diode laser being attached to a substrate (12), converging means (5) (such as a lens). During measuring, such converging means (5) converges the measuring beam in an action plane and converges in the laser cavity the measuring beam radiation that has been back-scattered by an object to generate a self-mixing effect and means for measuring the self-mixing effect. Later means comprise a photo diode (4) and an associated signal processing circuitry. According to an essential aspect of the invention, that the diode laser (3) is configured to emit laser radiation of a wavelength for which the substrate (12) being attached to the diode laser (3) is transparent. This configuration leads to an essentially simple (and therefore cheap) sensor module.

Abstract: A system includes a laser generator, and a signal distortion generator circuit inline with the laser generator modulation signal and configured to generate distortion vectors in any of four distortion vector quadrants.

Abstract: A laser self-mixing measuring device is provided, comprising a laser with a laser cavity and a surface arranged along the optical path of the laser beam which redirects incident laser light back into the laser cavity. The surface comprises a periodic structure which diffracts the laser light into partial beams.