Abstract: A laser module includes one or more connectors and a laser source. The one or more connectors are configured to receive electrical power from, and to output a light beam to, a panel of a system. The laser source is configured to (i) be powered by the electrical power, and (ii) produce the light beam using the electrical power. The one or more connectors and the laser source are detachable from the panel, and when detached from the panel, the laser source is not powered by the electrical power.

Abstract: An Integrated Circuit (IC) includes a digital phase-locked loop (DPLL) circuit and DPLL Diagnostics circuitry (DPLL-DC). The DPLL circuit includes an oscillator, a digital phase detector and a digital feedback bus (DPLL-DFB). The oscillator is configured to generate an output signal. The digital phase detector is configured to generate a digital feedback signal indicative of a phase difference between the output signal and a reference input signal. The DPLL-DFB is configured to feed-back the digital feedback signal for controlling the oscillator. The DPLL-DC is coupled to the DPLL-DFB and is configured to monitor events depending at least on the digital feedback signal transferred on the DPLL-DFB.

Abstract: Embodiments are disclosed for full-rate phase detection for a pulse amplitude modulation N (PAM-N) signal. The example method includes sampling an incoming signal in one or more sampling times. The example method further includes determining that an amplitude associated with a current sampling time is within an upper threshold and a lower threshold for each sampling time of the one or more sampling times. The example method further includes upon determining that the amplitude of the current sampling time is within the upper threshold and the lower threshold, determining an amplitude range associated with an immediately preceding sampling time and an amplitude range associated with an immediately subsequent sampling time. The example method further includes determining a transition status representing one of an upward transition, a downward transition, or no transition with respect to the current sampling time.

Abstract: Embodiments are disclosed for generating a lookup table value for calibrating a lookup table circuit in an optical transmitter. The example method includes generating a calibration signal. The calibration signal encodes a plurality of bits in a number of amplitude levels. The example method further includes transmitting the calibration signal to a module under calibration and transmitting a symbol sequence of defined length to a reference module. The reference module compares the symbol sequence with a distorted signal received from the module under calibration to generate a set of condition count statistics. The example method further includes receiving the set of condition count statistics from the receiver in the reference module and calculating a lookup table value based on the set of condition count statistics. The example method further includes transmitting the lookup table value to a transmitter associated with the module under calibration.

Abstract: Embodiments are disclosed for equalizing input signals for communication systems. An example method includes receiving an input signal. The input signal encodes a plurality of bits in a number of amplitude levels. The example method further includes converting the input signal to an equalized output signal using a plurality of lookup table circuits. The equalized output signal encodes a plurality of symbols in a number of amplitude levels. The example method further includes feeding the equalized output signal to an output driver circuit.

Abstract: A circuit providing electrostatic discharge (ESD) protection and a method and an apparatus for testing ESD protection on an integrated circuit are described. The circuit includes a first ESD protection circuit and a test pad and a second ESD protection circuit and a second pad for the application, not probed during manufacturing of the integrated circuit. In some examples, the method includes providing a first, second, third, and fourth test current to the circuit providing ESD protection, measuring a first second, third, and fourth voltage drop across the circuit, and determining an operating condition for the first ESD protection circuit and the test pad and the second ESD protection circuit and the second bond pad based on expected values of the first voltage drop, the second voltage drop, the third voltage drop, and the fourth voltage drop.

Abstract: Embodiments are disclosed for equalizing a pulse amplitude modulation signal for a receiver in a communication system. An example method includes receiving an electronic signal. The electronic signal encodes a plurality of symbols in a number of amplitude levels in a plurality of pulses in the electronic signal. The example method further includes estimating multiple symbol values using all possible values of an immediately preceding symbol for each symbol in the electronic signal. Each estimated symbol value is determined using one of the possible values of the immediately preceding symbol. The example method further includes receiving an actual value of the immediately preceding symbol and selecting an actual estimated symbol value from the multiple symbol values based on the actual value of the immediately preceding symbol. The actual estimated symbol value may be used as the actual value for selecting an estimated symbol value of an immediately subsequent symbol.

Abstract: The invention comprises a multilevel optical signal system comprising two or more light source branches and an optical power-combiner, wherein each branch comprising a light source, an optical modulator and an electrical driver for the modulator, wherein each electrical driver is configured for being driven by electrical signals to drive the modulator to modulate the light generated by the light source into a corresponding 2-level data signal such that the respective 2-level data signals differs in power level.

Abstract: A TIA includes first and second input terminals for differentially receiving an input current signal, and first and second amplification circuits. The first amplification circuit includes a first Alternating-Current (AC) path and a first Direct-Current (DC) path that are configured to amplify in parallel respective first AC and DC components of the input current signal flowing via the first input terminal, and a first combiner configured to sum the amplified first AC and DC components. The second amplification circuit includes a second AC path and a second DC path that are configured to amplify in parallel respective second AC and DC components of the input current signal flowing via the second input terminal, and a second combiner configured to sum the amplified second AC and DC components. First and second output terminals are configured for outputting an output voltage signal formed between outputs of the first and second combiners.

Abstract: A modulator driver circuit for providing a drive voltage to an electro-absorption modulator, such a Franz-Keldysh modulator, or to a micro-ring modulator, and an optical transmitter including such driver circuit, where said driver circuit includes a differential amplifier and at least one differential branch of the differential amplifier being provided with a voltage offset. This provides for a bias voltage being adjustable within the driver circuit itself. Preferably, the differential amplifier is arranged for supplying drive voltage to two complementary driver outputs providing a reverse bias relative to the modulator. In one embodiment, the differential amplifier includes a cascode in the differential branch not being provided with the voltage offset.

Abstract: The invention comprises a multilevel optical signal system comprising two or more light source branches and an optical power-combiner, wherein each branch comprising a light source, an optical modulator and an electrical driver for the modulator, wherein each electrical driver is configured for being driven by electrical signals to drive the modulator to modulate the light generated by the light source into a corresponding 2-level data signalsuch that the respective 2-level data signals differs in power level.

Abstract: A modulator driver circuit for providing a drive voltage to an electro-absorption modulator, such a Franz-Keldysh modulator, or to a micro-ring modulator, and an optical transmitter comprising such driver circuit, where said driver circuit comprises a differential amplifier and at least one differential branch of the differential amplifier being provided with a voltage offset. This provide for a bias voltage being adjustable within the driver circuit itself. Preferably, said differential amplifier is arranged for supplying drive voltage to two complementary driver outputs providing a reverse bias relative to the modulator. In one embodiment, said differential amplifier comprises a cascode in the differential branch not being provided with the voltage offset.

Abstract: A method for optical transmission of high speed data and an optical receiver for receiving such high speed data is provided. The method includes transmitting an optical signal having a first logic-high and first logic-low defining a first modulation amplitude that is sub-band modulated with a toggling signal having a first toggling amplitude with a first modulation index, receiving the optical signal with an optical receiver circuit and converting the optical signal to an intermediate electrical signal, IES, having: a second logic-high and a second logic-low defining a second modulation amplitude, and a second toggling amplitude having a second modulation index, providing a decision threshold relative to the IES as a function of the second modulation amplitude, and adjusting the threshold by determining the second toggling amplitude and adjusting the threshold relative to the IES based on proportionality between the second toggling amplitude and the second modulation amplitude.z.

Abstract: The present invention relates to a flexible method of provide chips for optical interconnect with different number of channels.

Abstract: A method of calculating a transmitter and dispersion penalty for predicting optical link signal quality, includes provide an optical link; capture an averaged eye, using an optical test signal sequence to drive the transmitter with the oscilloscope receiver having an oscilloscope bandwidth as available; and from the averaged eye, capturing histograms A1; capture a non-averaged eye using an optical test signal sequence to drive the transmitter, and from the non-averaged eye, capturing histograms B1; de-convolve histograms A1 from histograms B1; filter waveform from 1) convolve the filtered waveform from 4) with the estimate of the noise from 3); calculate “soft” TDP based on said probability distribution function.

Abstract: A method for an optical transmitter, receiver or transceiver allowing determination of a signal property of a first binary signal such as the modulation amplitude. The method applies a reference stage which is modulated by the signal content of the first binary signal to allow the determination.

Abstract: A method and an optical receiver implementing this method suitable for robustly receiving unencoded optical data. The method sets the threshold for the receiver using values relating to the high and low values of a binary signal. However, for some data patterns these values may not be accurately determined, such as for extended periods of constant high or low values being transmitted. In this case the method, in one embodiment, assumes that the extinction ratio of the signal is substantially constant and is thereby able to track the threshold for the signal.