Abstract: An optical communication system, device, and method are disclosed. An illustrative optical communication system is disclosed to include a carrier Integrated Circuit (IC) chip having an amplifier circuit, a bias plane, and a ground plane. The amplifier circuit, bias plane, and the ground plane may each operate at or above a nominal voltage of zero volts. A laser diode may be integrated with an electro-absorption modulator into a single IC chip, where the laser diode is mounted on the carrier IC chip and is electrically connected with the amplifier circuit of the carrier IC chip through a bond wire.

Abstract: A TIA circuit is provided that utilizes current steering to adjust the gain of a TIA of the TIA circuit. As the optical input power of the optoelectronic (OE) detector that is coupled to the input of the TIA increases, the gain of the TIA is decreased via current steering, and as the optical input power of the OE detector decreases, the gain of the TIA is increased via current steering. Utilizing current steering to adjust the gain of the TIA allows the TIA circuit to have a configuration that has reduced power consumption compared to TIA circuits that use shunt feedback TIAs. In addition the TIA circuit configuration provides reduced peaking, improved linearization and high bandwidth.

Abstract: A TIA circuit is provided that utilizes current steering to adjust the gain of a TIA of the TIA circuit. As the optical input power of the optoelectronic (OE) detector that is coupled to the input of the TIA increases, the gain of the TIA is decreased via current steering, and as the optical input power of the OE detector decreases, the gain of the TIA is increased via current steering. Utilizing current steering to adjust the gain of the TIA allows the TIA circuit to have a configuration that has reduced power consumption compared to TIA circuits that use shunt feedback TIAs. In addition the TIA circuit configuration provides reduced peaking, improved linearization and high bandwidth.

Abstract: A burst-mode TIA circuit for use in PON receivers is provided that supports multiple data rates, has high receiver sensitivity, wide dynamic range, and that performs burst-mode synchronization very quickly. The multi-rate burst-mode TIA circuit has a high-speed data path that has low input-referred noise. Based on the chosen data rate at which the multi-rate burst-mode TIA circuit will operate, the rate select switch selects an appropriate feedback resistor of the resistive feedback network.

Abstract: A burst-mode TIA circuit for use in PON receivers is provided that supports multiple data rates, has high receiver sensitivity, wide dynamic range, and that performs burst-mode synchronization very quickly. The multi-rate burst-mode TIA circuit has a high-speed data path that has low input-referred noise. Based on the chosen data rate at which the multi-rate burst-mode TIA circuit will operate, the rate select switch selects an appropriate feedback resistor of the resistive feedback network.

Abstract: An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a single-to-differential variable gain amplifier having a variable resistor switch that substantially always operates in a triode region at all time. Said another way, the resistor switch is configured to operate in a triode region regardless of whether or not a first portion of an input signal to the variable gain amplifier is larger than a second portion of the input signal. The disclosed scheme helps to keep the variable resistor switch in the triode region in all cases of operation, thereby maintaining the linearity condition and reducing distortion in the variable gain amplifier.

Abstract: An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a first transistor receiving a first portion of an input signal received at the amplifier, a second transistor receiving a second portion of the input signal, an automatic gain control signal that is dynamically adjustable in response to variations in an output of the amplifier, and a varactor that has its capacitance adjusted by changes in the automatic gain control signal and, as a result, adjusts a position of a pole in a transfer function of the amplifier.

Abstract: A digitally-controlled transimpedance amplifier (TIA) circuit is provided in which a plurality of feedback loops are digitally controlled, including, but not limited to, the DC offset cancellation loop, the variable gain control loop, and the TIA feedback impedance adjustment loop. The digitally-controlled TIA circuit includes digital loop-control circuitry that consumes less area on the TIA IC chip than the analog circuitry traditionally used to perform the feedback loop control in the analog domain. In addition, because digital logic continues to shrink as IC processes continue to evolve, the size of the IC chip packages will further decrease over time, leading to a smaller footprint in systems in which they are employed. The digital loop control circuitry is also capable of independently varying the gains of multiple gain stages of the variable gain control circuit to provide better control over the gain stages and better overall performance of the TIA circuit.

Abstract: A digitally-controlled transimpedance amplifier (TIA) circuit is provided in which a plurality of feedback loops are digitally controlled, including, but not limited to, the DC offset cancellation loop, the variable gain control loop, and the TIA feedback impedance adjustment loop. The digitally-controlled TIA circuit includes digital loop-control circuitry that consumes less area on the TIA IC chip than the analog circuitry traditionally used to perform the feedback loop control in the analog domain. In addition, because digital logic continues to shrink as IC processes continue to evolve, the size of the IC chip packages will further decrease over time, leading to a smaller footprint in systems in which they are employed. The digital loop control circuitry is also capable of independently varying the gains of multiple gain stages of the variable gain control circuit to provide better control over the gain stages and better overall performance of the TIA circuit.

Abstract: An optical communication system, circuit, and Integrated Circuit (IC) chip are disclosed. The disclosed optical communication system includes a photodiode configured to receive light energy and convert the light energy into an electrical signal, an amplifier configured to receive the electrical signal from the photodiode and output an amplified electrical signal, and a control circuit comprising a biasing network that generates a modular logic level that scales with a bias voltage of the photodiode.

Abstract: An optical communication system, a linear optical receiver, and an Integrated Circuit (IC) chip are disclosed, among other things. One example of the disclosed IC chip includes a transimpedance amplifier that receives an input electrical signal from a photodiode and provides an amplified version of the input electrical signal as an output, at least one variable gain amplifier that receives the amplified electrical signal output by the transimpedance amplifier and a bandwidth control mechanism that extends a bandwidth of the second amplified output at a maximum gain of the second amplification phase and also reduces a peaking of the second amplified output at a minimum gain of the second amplification phase.

Abstract: An optical communication system, a linear optical receiver, and an Integrated Circuit (IC) chip are disclosed, among other things. One example of the disclosed IC chip includes a transimpedance amplifier that receives an input electrical signal from a photodiode and provides an amplified version of the input electrical signal as an output, at least one variable gain amplifier that receives the amplified electrical signal output by the transimpedance amplifier and a bandwidth control mechanism that extends a bandwidth of the second amplified output at a maximum gain of the second amplification phase and also reduces a peaking of the second amplified output at a minimum gain of the second amplification phase.

Abstract: An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a first transistor receiving a first portion of an input signal received at the amplifier, a second transistor receiving a second portion of the input signal, an automatic gain control signal that is dynamically adjustable in response to variations in an output of the amplifier, and a varactor that has its capacitance adjusted by changes in the automatic gain control signal and, as a result, adjusts a position of a pole in a transfer function of the amplifier.

Abstract: An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a single-to-differential variable gain amplifier having a variable resistor switch that substantially always operates in a triode region at all time. Said another way, the resistor switch is configured to operate in a triode region regardless of whether or not a first portion of an input signal to the variable gain amplifier is larger than a second portion of the input signal. The disclosed scheme helps to keep the variable resistor switch in the triode region in all cases of operation, thereby maintaining the linearity condition and reducing distortion in the variable gain amplifier.

Abstract: An optical communication system, circuit, and Integrated Circuit (IC) chip are disclosed. The disclosed optical communication system includes a photodiode configured to receive light energy and convert the light energy into an electrical signal, an amplifier configured to receive the electrical signal from the photodiode and output an amplified electrical signal, and a control circuit comprising a biasing network that generates a modular logic level that scales with a bias voltage of the photodiode.

Abstract: A low-power, direct-drive EML driver circuit is provided that reduces power consumption by reducing the amount of current needed to create the necessary voltage swing in the drive signal. In addition, the EML driver circuit has an impedance matching network that has reduced complexity and that can be made at reduced costs compared to the impedance matching network of a typical EML driver circuit.

Abstract: An optical communication system, a circuit, and a method of operating an optical communication system are provided. The optical communication system is disclosed to include a photodiode configured to receive optical signals and convert the received optical signals into electrical signals, a Trans-Impedance Amplifier (TIA) electrically connected with the photodiode such that the TIA receives the electrical signals from the photodiode and is configured to convert the electrical signals received from the photodiode into amplified electrical signals, and a feedback loop connected between an input of the TIA and an output of the TIA that includes a switchable capacitor bank connected thereto which introduces at least one zero into a feedback factor transfer function of the TIA thereby tuning out poles or equalizing delay introduced by a TIA input network connected between the photodiode and the input of the TIA.

Abstract: A transmitter is disclosed as being configured to encode optical signals in accordance with a multi-level coding scheme. The transmitter includes an Integrated Circuit architecture and partition that relaxes the bandwidth and linearity constraints of a gearbox-to-laser driver interface. In the proposed architecture, the gearbox Integrated Circuit aligns two or more digital data streams and transmits the aligned two or more data streams to the laser driver via separate signals.

Abstract: A gearbox IC is incorporated into an optical communications system to enable an optical link that incorporates the system to achieve data rates that are at least double that which are currently achievable in optical links. The gearbox IC is compatible with ASIC designs currently used in optical fiber links. The gearbox IC enables the data rate of the optical fiber link to be dramatically increased without requiring a redesign of the ASIC that is currently used in the optical fiber link. The gearbox IC performs data rate conversion and phase alignment for bit streams being transferred via the gearbox IC between the ASIC and an optical transceiver module of the optical communications system.

Abstract: A Tx IC and an Rx IC that use different supply voltages are mounted on a circuit board and interfaced via traces of the board. The configuration of the Tx IC is such that DC decoupling is provided between the ICs while also preventing inadvertent turn-on of the ESD diodes of the Rx IC. These features make it possible to provide DC decoupling between high-performance Tx ICs that use relatively high supply voltages and Rx ICs that use relatively low supply voltages without the need for AC coupling capacitors and while also preventing ESD protection of the Rx IC from being degraded.