Examples described herein relate to an analog front-end (AFE). The AFE includes a trans-impedance amplifier to receive an input current and generate a pair of the differential voltage signals based on the input current and a reference current. Further, the AFE includes a dynamic voltage slicer to receive the differential voltage signals at input terminals and supply digital voltages at output terminals. The dynamic voltage slicer includes a preamplifier to generate a pair of intermediate voltages based on the differential voltage signals sampled at a predetermined frequency. The dynamic voltage slicer also includes a voltage latch circuit coupled to the preamplifier, wherein the voltage latch circuit is to regenerate a pair of digital voltages based on the pair of the intermediate voltages. Moreover, the AFE includes a logic latch coupled to the dynamic voltage slicer to provide digital output states based on the pair of the digital voltages.

Apparatus and associated methods relate to an open-loop control circuit (OLCC) configured to determine a photodiode element (PDE) drive voltage as a function of a commanded photodiode gain level and a measured temperature signal. In an illustrative example the OLCC may receive a current temperature of an APD element. The OLCC may, for example, receive a commanded gain for the APD relative to a predetermined reference gain. The OLCC may, for example, retrieve a predetermined efficiency characteristic (PEC) of the APD based on the current temperature. If the temperature corresponds to a substantially non-linear portion of the PEC, the OLCC may, for example, determine the drive voltage as a function of the temperature and the commanded gain based on the PEC. Various embodiments may advantageously provide direct control of output gain of photodiodes over a wide dynamic range of temperature associated with the photodiode.

Disclosed herein is a system comprising: an avalanche photodiode (APD); a bias source configured to supply a reverse bias to the APD; a current meter configured to measure electric current through the APD; a controller configured to reduce the reverse bias to a value below a breakdown voltage of the APD from a value above the breakdown voltage when an intensity of light incident on the APD is above a threshold, and configured to determine the intensity of the light above the threshold based on the electric current through the APD when the reverse bias is below the breakdown voltage.

An example optical receiving device includes a photodiode to receive an optical signal, where the photodiode is configured to conduct a current that is based on an optical power of the optical signal, and a radio frequency (RF) gain circuitry to generate one or more analog electrical signals based on the current and based on gain provided by the RF gain circuitry. A power detector is configured to receive an analog electrical signal of the one or more analog electrical signals, to detect alternating current (AC) power of the optical signal based on the analog electrical signal, and to output a signal representing the AC power based on the detecting.

A silicon chip carrier includes at least two of a photosensitive P-I-N diode, a non-photosensitive P-I-N diode, a photosensitive P-(metal)-N diode, a non-photosensitive P-(metal)-N diode, and a Schottky diode all integrally formed in the same layers of the chip carrier. In some embodiments, diodes formed in the chip carrier provide photovoltaic power and power regulation to a circuit mounted on the chip carrier.

A silicon chip carrier includes at least two of a photosensitive P-I-N diode, a non-photosensitive P-I-N diode, a photosensitive P-(metal)-N diode, a non-photosensitive P-(metal)-N diode, and a Schottky diode all integrally formed in the same layers of the chip carrier. In some embodiments, diodes formed in the chip carrier provide photovoltaic power and power regulation to a circuit mounted on the chip carrier.

High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Systems and methods for optical data communication in high temperatures and harsh environments are provided herein. The embodiments utilize a combination of a short wavelength light source combined with a wide bandgap detector in order to transmit optical signals. An optical data communication system may include a light source connected to a light detector via an optical fiber. The light source and the light detector may also be physically adjacent to any dielectric gap that can be spanned without having an optical fiber intermediary.

An optical receiver capable of substantially measuring the phase and amplitude of a received intensity- or amplitude-modulated optical signal by performing digital-signal processing. In an example embodiment, a DSP of the receiver operates to reduce the detrimental effects of relative phase noise between the optical reference oscillator and optical carrier based on an optical pilot present in the received optical signal. The DSP may employ a sequence of digital filters configured to select a signal component that represents a non-vestigial modulation sideband and then perform signal equalization thereon. The signal equalization may include but is not limited to dispersion compensation. In some embodiments, the optical receiver can be a direct-detection optical receiver. In an example embodiment, the optical reference oscillator and optical carrier are generated using two respective independently running lasers that may or may not be co-located.

An example optical receiving device includes a photodiode to receive an optical signal, where the photodiode is configured to conduct a current that is based on an optical power of the optical signal, and a radio frequency (RF) gain circuitry to generate one or more analog electrical signals based on the current and based on gain provided by the RF gain circuitry. A power detector is configured to receive an analog electrical signal of the one or more analog electrical signals, to detect alternating current (AC) power of the optical signal based on the analog electrical signal, and to output a signal representing the AC power based on the detecting.