Abstract: Systems and methods for an asynchronous successive approximation register analog-to-digital converter (SAR ADC) with word completion algorithm may include a SAR ADC comprising a plurality of switched capacitors, a comparator, a metastability detector including a timer having a tunable time interval, and a successive approximation register. The SAR ADC may sample input signals at inputs of the switched capacitors; compare signals at outputs of the switched capacitors, each for a respective bit; sense whether a metastability condition exists for the comparator using the timer and setting a metastability flag upon each metastability detection for each bit; increase a value of the tunable time interval if more than one metastability flag is set during conversion of a sampled input signal; decrease a value of the tunable time interval if no metastability flags are set; and use the flags for a word completion in the cases when not all the bits have been evaluated.

Abstract: Systems and methods for a track and hold amplifier with extended dynamic range may include a track amplifier comprising a first PMOS transistor coupled to a first NMOS transistor, a second PMOS transistor coupled to a second NMOS transistor, a capacitor at gates of each NMOS and PMOS transistor, and a plurality of switches. The track and hold amplifier is operable to, during a tracking mode of the track and hold amplifier, couple a differential input signal to each NMOS and PMOS transistor via a first switch coupled to a first capacitor coupled to the gate of the first PMOS transistor and a second capacitor coupled to the gate of the first NMOS transistor, and via a second switch coupled to a third capacitor coupled to the gate of the second PMOS and a fourth capacitor coupled to the gate of the second NMOS transistor.

Abstract: Methods and systems for optical alignment to a silicon photonically-enabled integrated circuit may include aligning an optical assembly to a photonics die comprising a transceiver by, at least, communicating optical signals from the optical assembly into a plurality of grating couplers in the photonics die, communicating the one or more optical signals from the plurality of grating couplers to optical taps, with each tap having a first output coupled to the transceiver and a second output coupled to a corresponding output grating coupler, and monitoring an output optical signal communicated out of said photonic chip via said output grating couplers. The monitored output optical signal may be maximized by adjusting a position of the optical assembly. The optical assembly may include an optical source assembly comprising one or more lasers or the optical assembly may comprise a fiber array. Such a fiber array may include single mode optical fibers.

Abstract: Methods and systems for optoelectronics transceivers of a CMOS chip are disclosed and may include receiving optical signals from optical fibers via grating couplers, which may include a guard ring. A CW optical signal may be received from a laser source via optical couplers, and may be modulated using optical modulators, which may be Mach-Zehnder and/or ring modulators. Circuitry in the CMOS chip may drive the optical modulators. The modulated optical signal may be communicated out of the CMOS chip into optical fibers via grating couplers. The received optical signals may be communicated between devices via waveguides. The photodetectors may include germanium waveguide photodiodes, avalanche photodiodes, and/or heterojunction diodes. The CW optical signal may be generated using an edge-emitting and/or a vertical-cavity surface emitting semiconductor laser.

Abstract: Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers may include an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path. The system may generate a pseudo-random bit sequence (PRBS) signal, generate an optical signal in the Tx path by applying the PRBS signal to a modulator, communicate the optical signal to the BIST loopback path and convert the optical signal to an electrical signal utilizing a photodetector, where the photodetector is a replica of a photodetector in the main Rx path, and assess the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be on a single complementary-metal oxide semiconductor (CMOS) die, or on two CMOS die where a first comprises electronic devices and a second comprises optical devices.

Abstract: Methods and systems for two-dimensional mode-matching grating couplers may include in a photonic chip comprising a grating coupler at a surface of the photonic chip, where the grating coupler has increased scattering strength in a direction of a light wave traveling through the grating coupler: receiving an optical signal from a first direction within the photonic chip; and scattering the optical signal out of the surface of the photonic chip. A second optical signal may be received in the grating coupler from a second direction within the photonic chip. The second optical signal may be scattered out of the surface of the photonic chip. The increasing scattering strength may be caused by increased width scatterers along a direction perpendicular to the direction of light travel. The increased scattering strength may be caused by a transition of shapes of scatterers in the grating coupler.