Abstract: An electronic device may have a display with touch sensors. One or more shielding layers may be interposed between the display and the touch sensors. The shielding layers may include shielding structures such as a conductive mesh structure and/or a transparent conductive film. The shielding structures may be actively driven or passively biased. In the active driving scheme, one or more inverting circuits may receive a noise signal from a cathode layer in the display and/or from the shielding structures, invert the received noise signal, and drive the inverted noise signal back onto the shielding structures to prevent any noise from the display from negatively impacting the performance of the touch sensors. In the passive biasing scheme, the shielding structures may be biased to a power supply voltage.

Abstract: Systems and methods for programming an electronic display in a double-row manner are provided. A system may include processing circuitry that generates image data and an electronic display that programs multiple rows of display pixels with different pixel data of the image data at the same time. This may allow double-row interlaced driving to reduce or eliminate image artifacts due to intra-frame pauses.

Abstract: An electronic device may have a display with touch sensors. One or more shielding layers may be interposed between the display and the touch sensors. The shielding layers may include shielding structures such as a conductive mesh structure and/or a transparent conductive film. The shielding structures may be actively driven or passively biased. In the active driving scheme, one or more inverting circuits may receive a noise signal from a cathode layer in the display and/or from the shielding structures, invert the received noise signal, and drive the inverted noise signal back onto the shielding structures to prevent any noise from the display from negatively impacting the performance of the touch sensors. In the passive biasing scheme, the shielding structures may be biased to a power supply voltage.

Abstract: An optical source may include an optical gain chip that provides an optical signal and that is optically coupled to an SOI chip. The optical gain chip may include a reflective layer. Moreover, the SOI chip may include: a first optical waveguide, a first ring resonator that selectively optically coupled to a second optical waveguide and that performs phase modulation and filtering of the optical signal, the second optical waveguide, an amplitude modulator, and an output port. Note that the reflective layer in the optical gain chip and the amplitude modulator may define an optical cavity. Furthermore, a resonance of the first ring resonator may be aligned with a lasing wavelength, and the resonance of the first ring resonator and a resonance of the amplitude modulator may be offset from each other. Additionally, modulation of the first ring resonator and the amplitude modulator may be in-phase with each other.

Abstract: An optical source may include an optical gain chip that provides an optical signal and that is optically coupled to an SOI chip. The optical gain chip may include a reflective layer. Moreover, the SOI chip may include: a common optical waveguide, a splitter that splits the optical signal into optical signals, a first pair of resonators that are selectively optically coupled to the common optical waveguide and that are configured to perform modulation and filtering of the optical signals, and a first bus optical waveguide that is selectively optically coupled to the first pair of resonators. Furthermore, resonance wavelengths of the resonators may be offset from each other with a (e.g., fixed) separation approximately equal or corresponding to a modulation amplitude, and a reflectivity of the first pair of resonators may be approximately independent of the modulation.

Abstract: The disclosed embodiments relate to the design of a temperature sensor, which is integrated into a semiconductor chip. This temperature sensor comprises an electro-thermal filter (ETF) integrated onto the semiconductor chip, wherein the ETF comprises: a heater; a thermopile, and a heat-transmission medium that couples the heater to the thermopile, wherein the heat-transmission medium comprises a polysilicon layer sandwiched between silicon dioxide layers. It also comprises a measurement circuit that measures a transfer function through the ETF to determine a temperature reading for the temperature sensor.

Abstract: An optical signal modulator (modulator) includes, in part, a first multitude of diodes coupled in parallel and disposed along an outer periphery of the optical ring of the modulator, a second multitude of diodes coupled in parallel and disposed along the outer periphery of the optical ring, and a doped region adapted to supply heat to the optical ring. A pair of current sources supply substantially constant currents to the first and second multitude of diodes to generate a pair of electrical signals. The modulator further includes, in part, a control circuit adapted to control the temperature of the optical ring in accordance with the pair electrical signals. To achieve this, the control circuit varies the voltage applied to the doped region to vary the supplied heat. Alternatively, the control circuit applies a voltage to the optical ring to maintain a substantially constant resonant wavelength in the optical ring.

Abstract: A differential optical modulator includes, in part, a splitter splitting an incoming optical signal into first and second input signals, a first variable coupler generating a first differential output signal in response to the first input signal, and a second variable coupler generating a second differential output signal in response to the second input signal. The first variable coupler includes, in part, first and second couplers and a phase shifter disposed therebetween. The first coupler generates a pair of internal signals in response to the first input signal. The second coupler generates the first differential output signal. The second variable coupler includes, in part, third and fourth couplers and a phase shifter disposed therebetween. The third coupler generates a pair of internal signals in response to the second input signal. The fourth coupler generates the second differential output signal.

Abstract: An integrated circuit that includes an optical receiver is described. This integrated circuit may include an optical receiver. The optical receiver may include a photodiode that receives an optical signal and that outputs a corresponding current. Moreover, the optical receiver may include an inductor that is electrically coupled to the photodiode. Furthermore, the optical receiver may include a resistive analog front-end stage that is electrically coupled to the inductor. Note that the inductor may have a resistance per unit length that is greater than a first threshold value (such as 40 m?/?m), and the inductor may be approximately dispersion-less. For example, a Q factor for inductive peaking associated with the inductor is less than a second threshold value (such as 5).

Abstract: A DC-coupled burst-mode optical receiver is described. The optical receiver may include an input node that receives a current, e.g., from an optoelectronic converter (such as a photodiode). Moreover, the optical receiver may include a current amplifier, coupled to the input node, that provides an output current based at least in part on the current, where the current amplifier has a shunt feedback path that reduces a bias sensitivity of the current amplifier and a feed-forward path that reduces a DC bias current of the current amplifier. Furthermore, the optical receiver may include a TIA, electrically coupled to the current amplifier, that converts the output current to an output voltage. Additionally, the optical receiver may include a feedback loop coupling an output of the TIA to an input of the feed-forward path.

Abstract: An optical source may include an optical gain chip that provides an optical signal and that is optically coupled to an SOI chip. The optical gain chip may include a reflective layer. Moreover, the SOI chip may include: a first optical waveguide, a first ring resonator that selectively optically coupled to a second optical waveguide and that performs phase modulation and filtering of the optical signal, the second optical waveguide, an amplitude modulator, and an output port. Note that the reflective layer in the optical gain chip and the amplitude modulator may define an optical cavity. Furthermore, a resonance of the first ring resonator may be aligned with a lasing wavelength, and the resonance of the first ring resonator and a resonance of the amplitude modulator may be offset from each other. Additionally, modulation of the first ring resonator and the amplitude modulator may be in-phase with each other.

Abstract: An optical source may include an optical gain chip that provides an optical signal and that is optically coupled to an SOI chip. The optical gain chip may include a reflective layer. Moreover, the SOI chip may include: a common optical waveguide, a splitter that splits the optical signal into optical signals, a first pair of resonators that are selectively optically coupled to the common optical waveguide and that are configured to perform modulation and filtering of the optical signals, and a first bus optical waveguide that is selectively optically coupled to the first pair of resonators. Furthermore, resonance wavelengths of the resonators may be offset from each other with a (e.g., fixed) separation approximately equal or corresponding to a modulation amplitude, and a reflectivity of the first pair of resonators may be approximately independent of the modulation.

Abstract: An integrated circuit that includes an optical receiver is described. This integrated circuit may include an optical receiver. The optical receiver may include a photodiode that receives an optical signal and that outputs a corresponding current. Moreover, the optical receiver may include an inductor that is electrically coupled to the photodiode. Furthermore, the optical receiver may include a resistive analog front-end stage that is electrically coupled to the inductor. Note that the inductor may have a resistance per unit length that is greater than a first threshold value (such as 40 m?/?m), and the inductor may be approximately dispersion-less. For example, a Q factor for inductive peaking associated with the inductor is less than a second threshold value (such as 5).

Abstract: An optical receiver receives a photocurrent from a photosensor and uses a transimpedance element to convert the photocurrent into an input voltage signal. An amplifier then amplifies the input voltage signal to produce a receiver output. During this process, a reference-voltage-generation circuit generates a reference voltage for the amplifier. This reference-voltage-generation circuit includes a data-detection circuit that detects data on the input voltage signal, and an adjustable low-pass filter, which filters the input voltage signal to produce the reference voltage. During a faster operating mode, which occurs when the data-detection circuit does not detect data on the input voltage signal, the filter has a cutoff frequency f1. During a slower operating mode, which starts a bias-delay time tBD after the data-detection circuit detects data on the input voltage signal, and lasts until the data-detection circuit no longer detects data, the filter has a lower cutoff frequency f2.

Abstract: An optical receiver receives a photocurrent from a photosensor and uses a transimpedance element to convert the photocurrent into an input signal. Next, an amplifier amplifies the input signal to produce an amplified input signal. At the same time, a clock-recovery circuit generates a clock signal, which is used to clock the amplified input signal to produce a receiver output. During an initial-calibration operation, the clock-recovery circuit phase-aligns a locally generated reference signal with transitions in the amplified input voltage signal to produce the clock signal by: feeding the reference signal through a delay-locked loop to produce a set of equally spaced phases; using the set of equally spaced phases to sample a preamble in the amplified input voltage signal to detect a crossing point; choosing a corresponding phase from the set of equally spaced phases based on the crossing point; and using the chosen phase to produce the clock signal.

Abstract: The disclosed embodiments relate to the design of a temperature sensor, which is integrated into a semiconductor chip. This temperature sensor comprises an electro-thermal filter (ETF) integrated onto the semiconductor chip, wherein the ETF comprises: a heater; a thermopile, and a heat-transmission medium that couples the heater to the thermopile, wherein the heat-transmission medium comprises a polysilicon layer sandwiched between silicon dioxide layers. It also comprises a measurement circuit that measures a transfer function through the ETF to determine a temperature reading for the temperature sensor.

Abstract: An integrated optical modulator includes, in part, a pair of waveguides and an inductor. The first waveguide is adapted to receive an incoming optical signal. The second waveguide includes a portion placed in proximity of the first waveguide so as to enable the incoming optical signal travelling in the first waveguide to couple to the second waveguide. The second waveguide comprises a p-n junction. The inductor has a first terminal coupled to the p-n junction and a second terminal coupled to a contact pad. The second waveguide has a circular shape. The inductor optionally has a spiral shape.

Abstract: An optical signal modulator (modulator) includes, in part, a first multitude of diodes coupled in parallel and disposed along an outer periphery of the optical ring of the modulator, a second multitude of diodes coupled in parallel and disposed along the outer periphery of the optical ring, and a doped region adapted to supply heat to the optical ring. A pair of current sources supply substantially constant currents to the first and second multitude of diodes to generate a pair of electrical signals. The modulator further includes, in part, a control circuit adapted to control the temperature of the optical ring in accordance with the pair electrical signals. To achieve this, the control circuit varies the voltage applied to the doped region to vary the supplied heat. Alternatively, the control circuit applies a voltage to the optical ring to maintain a substantially constant resonant wavelength in the optical ring.

Abstract: An integrated optical modulator includes, in part, a pair of waveguides and an inductor. The first waveguide is adapted to receive an incoming optical signal. The second waveguide includes a portion placed in proximity of the first waveguide so as to enable the incoming optical signal travelling in the first waveguide to couple to the second waveguide. The second waveguide comprises a p-n junction. The inductor has a first terminal coupled to the p-n junction and a second terminal coupled to a contact pad. The second waveguide has a circular shape. The inductor optionally has a spiral shape.

Abstract: A differential optical modulator includes, in part, a splitter splitting an incoming optical signal into first and second input signals, a first variable coupler generating a first differential output signal in response to the first input signal, and a second variable coupler generating a second differential output signal in response to the second input signal. The first variable coupler includes, in part, first and second couplers and a phase shifter disposed therebetween. The first coupler generates a pair of internal signals in response to the first input signal. The second coupler generates the first differential output signal. The second variable coupler includes, in part, third and fourth couplers and a phase shifter disposed therebetween. The third coupler generates a pair of internal signals in response to the second input signal. The fourth coupler generates the second differential output signal.