Abstract: A sensory system (10, 100) for improving and/or restoring sensation to a foot or hand of a patient. The system (10, 100) includes at least one force sensor (12, 102) implanted subcutaneously within a finger or palm of a hand or on a plantar surface of a foot of a patient and a base unit (18, 104) that is worn externally by the patient or is implanted subcutaneously in the patient. The force sensor (12, 102) is configured to transmit wireless communication signals to the base unit (18, 104) in response to and concerning forces sensed by the force sensor, and base unit (18, 104) is configured to apply peripheral nerve stimulation based on the wireless communication signals received from the force sensor (12) or to transmit the sensory data to a separate neural implant (106). The force sensor (12, 102) transmits the wireless communication signals to the base unit (18, 104) by magnetic human body communication (mHBC).

Abstract: Provided are methods for optical communication, comprising: generating a phase difference signal with heterodyne or homodyne phase-locked-loop (PLL) from between an optical input signal and a local laser source; controlling the local laser source with the phase difference signal; demodulating the optical input signal using the local laser source as a carrier signal to generate a baseband output signal; and controlling the heterodyne or homodyne PLL and the demodulation with an electrical oscillator signal. Also provided are related methods.

Abstract: Provided are systems and methods for photonic-electronic neural network computation. In an embodiment, arrays of input data are processed in an optical domain and applied through a plurality of photonic-electronic neuron layers, such as in a neural network. The data may be passed through one or more convolution cells, training layers, and classification layers to generate output information. In embodiments, various types of input data, e.g., audio, video, speech, analog, digital, etc., may be directly processed in the optical domain and applied to any numbers of layers and neurons in various neural network configurations. Such systems and methods may also be integrated with one or more photonic-electronic systems, including but not limited to 3D imagers, optical phased arrays, photonic assisted microwave imagers, high data-rate photonic links, and photonic neural networks.

Abstract: Provided are systems and methods of using of optical delay lines in RF imagers, e.g., Ultra-wideband (UWB) imagers. In an embodiment, a modulator can be configured to convert radio-frequency signals to optical signal. First and second optical delay lines delay respective first and second optical signals converted by the modulator, and a photodetector can convert the delayed optical signals to at least one electrical signal corresponding to at least one pixel of a radio frequency image. The disclosed systems and methods can also further form a radio-frequency image based on output from the photodetector. In still further embodiments, the photodetector can receive modulated optical signals from an array of optical delays. Also provided are related methods of using the disclosed systems and devices.

Abstract: Provided are methods for optical communication, comprising: generating a phase difference signal with heterodyne or homodyne phase-locked-loop (PLL) from between an optical input signal and a local laser source; controlling the local laser source with the phase difference signal; demodulating the optical input signal using the local laser source as a carrier signal to generate a baseband output signal; and controlling the heterodyne or homodyne PLL and the demodulation with an electrical oscillator signal. Also provided are related methods.

Abstract: An optical phased array includes, in part, N optical signal emitting elements, and N lenses each associated with a different one of the N optical signal emitting elements and positioned to form an image of its associated signal emitting element, where N is an integer greater than 1. The optical signal emitting elements may be a grating coupler, an edge coupler, and the like. At least a number of the lenses may be formed from Silicon. The optical phased array may optionally include one or more concave or convex lens positioned between the signal emitting elements and the N lenses. The optical signal emitting elements may be formed in a silicon dioxide layer formed above a semiconductor substrate and the lenses may be formed from Silicon disposed above the silicon dioxide layer. The optical signal emitting elements may receive an optical signal generated by the same source.

Abstract: Provided are systems and methods of using of optical delay lines in RF imagers, e.g., Ultra-wideband (UWB) imagers. In an embodiment, a modulator can be configured to convert radio-frequency signals to optical signal. First and second optical delay lines delay respective first and second optical signals converted by the modulator, and a photodetector can convert the delayed optical signals to at least one electrical signal corresponding to at least one pixel of a radio frequency image. The disclosed systems and methods can also further form a radio-frequency image based on output from the photodetector. In still further embodiments, the photodetector can receive modulated optical signals from an array of optical delays. Also provided are related methods of using the disclosed systems and devices.

Abstract: A camera includes, in part, an optical signal source generating a frequency varying optical signal, a multitude of pixels arranged along rows and columns, an optical focusing element, and an opto-electronic circuit. A portion of the optical signal generated by the optical signal is caused to reflect from a target object and then directed toward the pixels. A multitude of samples of a second portion of the optical signal are combined with the signals received by the pixels to generate a multitude of combined optical signals. The optical signals so combined are converted to electrical signals. Each electrical signal has a frequency defined by a difference between a frequency of the second portion of the optical signal and a frequency of a signal received from a pixel. The frequency differences are used to form an image of the target object.

Abstract: An optical phase shifter includes, in part, a waveguide, a heating element adapted to heat the waveguide, and a cooling element adapted to cool the waveguide. The heating element may be integrated within a substrate in which the waveguide is formed. The cooling element is biased to maintain the temperature of the waveguide within a predefined range characterized by a substantially high gradient of the thermal constant of the waveguide. The optical phase shifter may optionally include a substrate on which the waveguide is positioned. The substrate may include, in part, through substrate vias for supplying electrical signals to the cooling element. A control circuit supplies electrical signals to the heating and cooling elements. The control circuit may maintain the cooling element and heating element on concurrently. Alternatively, the control circuit may turn off the cooling element before turning on the heating element.

Abstract: A laser frequency control apparatus comprising: (a) a laser; (b) an oscillator configured to receive an output of the laser and to output a modulated signal; (c) a frequency reference configured to receive the modulated signal and to provide an output signal; and (d) a mixer configured to mix at least a portion of the output signal with an output of the oscillator to generate a mixer output, wherein the mixer output is injected to a section of the laser.

Abstract: An optical phased array includes, in part, a multitude of optical signal emitters and a multitude of optical signal phase/delay elements each associated with and disposed between a different pair of the optical signal emitters. Each optical signal phase/delay element is adapted to cause a phase/delay shift between the optical signals emitted from its associated pair of optical signal emitters. Each optical signal phase/delay element is optically a ring resonator that includes a p-i-n junction. By varying the bias applied to the p-i-n junction, the phase/delay generated by the ring resonator is varied. Furthermore, each optical signal emitter is optionally an optical grating having a multitude of grooves. The groove lengths of the optical gratings are optionally selected so as to increase along the direction of travel of the input optical signal through the optical phase array.

Abstract: A laser frequency control apparatus comprising: (a) a laser; (b) an oscillator configured to receive an output of the laser and to output a modulated signal; (c) a frequency reference configured to receive the modulated signal and to provide an output signal; and (d) a mixer configured to mix at least a portion of the output signal with an output of the oscillator to generate a mixer output, wherein the mixer output is injected to a section of the laser.

Abstract: An optical phase array, includes, in part, N optical signal emitting elements, and N lenses each associated with a different one of the N optical signal emitting elements and positioned to form an image of its associated signal emitting element, where N is an integer greater than 1. The optical signal emitting elements may be a grating coupler, an edge coupler, and the like. At least a number of the lenses may be formed from Silicon. The optical phased array may optionally include one or more concave or convex lenss positioned between the signal emitting elements and the N lenses. The optical signal emitting elements may be formed in a silicon dioxide layer formed above a semiconductor substrate and the lenses may be formed from Silicon disposed above the silicon dioxide layer. The optical signal emitting elements may receive an optical signal generated by the same source.

Abstract: An optical phase shifter includes, in part, a waveguide, a heating element adapted to heat the waveguide, and a cooling element adapted to cool the waveguide. The heating element may be integrated within a substrate in which the waveguide is formed. The cooling element is biased to maintain the temperature of the waveguide within a predefined range characterized by a substantially high gradient of the thermal constant of the waveguide. The optical phase shifter may optionally include a substrate on which the waveguide is positioned. The substrate may include, in part, through substrate vias for supplying electrical signals to the cooling element. A control circuit supplies electrical signals to the heating and cooling elements. The control circuit may maintain the cooling element and heating element on concurrently. Alternatively, the control circuit may turn off the cooling element before turning on the heating element.

Abstract: An opto-electrical oscillator includes, in part, first and second optical phase modulators, a coupler, an optical-to-electrical signal conversion circuit, and a control circuit. The first optical phase modulator modulates the phase of a first optical signal in response to a first feedback signal to generate a first phase modulated signal. The second optical phase modulator modulates the phase of a second optical signal in response to a second feedback signal to generate a second phase modulated signal. The first and second optical signals travel through first and second optical paths respectively and are generated from the same optical source. The optical-to-electrical signal conversion circuit receives an optical signal from the coupler and in response generates an electrical signal applied to the control circuit. The output signals of the control circuit cause the first and second feedback signals to be out of phase.

Abstract: An opto-electrical oscillator includes, in part, first and second optical phase modulators, a coupler, an optical-to-electrical signal conversion circuit, and a control circuit. The first optical phase modulator modulates the phase of a first optical signal in response to a first feedback signal to generate a first phase modulated signal. The second optical phase modulator modulates the phase of a second optical signal in response to a second feedback signal to generate a second phase modulated signal. The first and second optical signals travel through first and second optical paths respectively and are generated from the same optical source. The optical-to-electrical signal conversion circuit receives an optical signal from the coupler and in response generates an electrical signal applied to the control circuit. The output signals of the control circuit cause the first and second feedback signals to be out of phase.

Abstract: An electro-optical circuit, includes in part, a modulator, a signal splitter, N signal paths each having one or more signal processing components, N photo-diodes and a signal combiner. The modulator modulates an optical signal using an electrical input signal. The splitter splits the modulated optical signal into N optical signals each delivered to a different one of the N paths for processing by the associated signal processing component(s). Each photo-diode converts an optical signal it receives from its associated optical signal processing component(s) to a current signal. The signal combiner combines the N current signals it receives from the N photo-diodes to generate an output current signal. The signal processing component(s) may be a variable optical delay component, a variable optical gain/attenuation component, or both thus enabling the output current signal to represent a filtered version of the electrical input signal.

Abstract: A self-equalizing photo-detector (SEPD) includes, in part, a multitude of optical splitters and photo detectors, and at least one optical delay element. The first optical splitter splits an optical signal into second and third optical signals. The optical delay element delays the second optical signal to generate a fourth optical signal. The second optical splitter splits a signal representative of the fourth optical signal to generate fifth and sixth optical signals. The first photo detector receives the third optical signal via a first optical path, has an anode terminal coupled to an output terminal of the detector and a cathode terminal coupled to a first supply voltage. The second photo detector receives the sixth optical signal via a second optical path, has an anode terminal coupled to a second supply voltage and a cathode terminal coupled to the output terminal of the detector.

Abstract: An opto-electrical oscillator includes, in part, first and second optical phase modulators, a coupler, an optical-to-electrical signal conversion circuit, and a control circuit. The first optical phase modulator modulates the phase of a first optical signal in response to a first feedback signal to generate a first phase modulated signal. The second optical phase modulator modulates the phase of a second optical signal in response to a second feedback signal to generate a second phase modulated signal. The first and second optical signals travel through first and second optical paths respectively and are generated from the same optical source. The optical-to-electrical signal conversion circuit receives an optical signal from the coupler and in response generates an electrical signal applied to the control circuit. The output signals of the control circuit cause the first and second feedback signals to be out of phase.

Abstract: An electro-optical oscillator includes, in part, a modulator, a signal splitter, N photodiodes with N being an integer greater than one, a signal combiner, and a filter. The modulator modulates an optical signal in accordance with a feedback signal. The splitter splits the modulated optical signal into N optical signals each delivered to a different one of N photo-diodes. Each of the N photo-diodes converts the optical signal it receives to a current signal. The signal combiner combines the N current signals received from the N photo-diodes to generate a combined current signal. The filter filters the combined current signal and generates the feedback signal. The electro-optical oscillator optionally includes, in part, N variable optical gain/attenuation components each amplifying/attenuating a different one of the N optical signals generated by the splitter.