Optical signal receiver, an associated photonic integrated circuit (RxPIC), and method improving performance

An optical receiver photonic integrated circuit (RxPIC) comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal with wavelengths within an optical signal wavelength grid from an optical telecommunication source;
• a plurality of gain clamped semiconductor optical amplifiers (GC-SOAs) integrated at the input of the chip, outputs from said amplifiers optically coupled through a vernier to an input of the optical demultiplexer, one of the GC-SOAs selected to receive the multiplexed channel signal for amplification;
• an optical demultiplexer integrated in the chip and optically coupled to the GC-SOAs to receive the amplified, multiplexed channel signal from the selected GC-SOA and provide the individual channel signals on respective output waveguides from the optical demultiplexer;
• and
• a plurality of photodetectors integrated in the chip and each optically coupled to one of the output waveguides to receive a demultiplexed channel signal and convert it to an electrical signal.

An optical receiver photonic integrated circuit (RxPIC) comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal with wavelengths within an optical signal wavelength grid from an optical telecommunication source;
• an optical component integrated into the chip to remove any residual gain clamping signal from the output of an integrated gain clamped semiconductor optical amplifier (GC-SOA) to receive the multiplexed channel signal from the input;
• an optical demultiplexer integrated in the chip and optically coupled to the GC-SOA to receive the amplified, multiplexed channel signal and provide the individual channel signals on respective output waveguides from the optical demultiplexer;
• and
• a plurality of photodetectors integrated in the chip and each optically coupled to one of the output waveguides to receive a demultiplexed channel signal and convert it to an electrical signal.

An optical receiver photonic integrated circuit (RxPIC) comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal with wavelengths within an optical signal wavelength grid from an optical telecommunication source;
• a gain clamped semiconductor optical amplifier (GC-SOA) integrated in the chip at the input to amplify the multiplexed channel signal for equalized spectral amplification across the channel signal grid;
• an optical component integrated into the GC-SOA to render its amplified output polarization insensitive, the component comprising a periodic grating that is provided within the GC-SOA, the grating designed to be loss selective of one polarization mode over the other;
• an optical demultiplexer integrated in the chip and optically coupled to the GC-SOA to receive the amplified, multiplexed channel signal and provide the individual channel signals on respective output waveguides from the optical demultiplexer;
• and
• a plurality of photodetectors integrated in the chip and each optically coupled to one of the output waveguides to receive a demultiplexed channel signal and convert it to an electrical signal.

An optical receiver comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal from an optical telecommunication source with channel wavelengths within a channel signal grid;
• an optical amplifier integrated at the input of the chip to receive and amplify the multiplexed channel signal and coupled to an integrated on-chip optical waveguide;
• an arrayed waveguide grating (AWG) integrated in the chip and optically coupled via the optical waveguide to receive the amplified multiplexed channel signal and provide individual channel signals on respective output waveguides from the AWG;
• a plurality of photodetectors integrated in the chip and each optically coupled to one of the output waveguides to respectively receive a demultiplexed channel signal and convert the signal to an electrical signal;
• the improvement comprising a plurality of semiconductor optical amplifiers integrated at the input of the chip and optically coupled to a single input of the AWG, one of the amplifiers with the best performance selected to receive the multiplexed channel signal for amplification.

A monolithic semiconductor optical receiver chip comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal having wavelengths within a channel signal wavelength grid from an optical telecommunication source;
• a gain clamped optical amplifier (GC-OA) having an active region and coupled to receive the multiplexed channel signal at the input of the chip to receive the multiplexed channel signal, the amplifier optically coupled to an on-chip integrated optical waveguide;
• a periodic grating provided in lateral juxtaposition and longitudinal coextensive to the GC-SOA active region to generate a gain clamped signal;
• an arrayed waveguide grating (AWG) integrated in the chip and optically coupled via the optical waveguide to receive the amplified, multiplexed channel signal and provide individual channel signals on respective output waveguides from the AWG;
• a plurality of photodetectors integrated in the chip, one optically coupled to each of the AWG output waveguides to respectively receive a demultiplexed channel signal and convert the signal to an electrical signal.

A monolithic semiconductor optical receiver chip comprising:

• a single monolithic InP chip having an input to receive a multiplexed channel signal having wavelengths within a channel signal wavelength grid from an optical telecommunication source;
• an arrayed waveguide grating (AWG) integrated in the chip and optically coupled via the optical waveguide to receive the multiplexed channel signal and provide individual channel signals on respective output waveguides from the AWG;
• a plurality of photodetectors integrated in the chip, one optically coupled to each of the AWG output waveguides to respectively receive a demultiplexed channel signal and convert the signal to an electrical signal;
• the improvement comprising the placement geometry of the AWG output waveguides in fan-out shape on the chip where the waveguide coupled photodetectors are placed along at least two sides of the chip reducing the required layout area of the chip.

A monolithic receiver photonic integrated circuit (RxPIC) InP-based chip comprising:

• a gain-clamped semiconductor laser amplifier (GC-SOA) having an active region and integrated at the input of the chip to receive a multiplexed channel signal and provide substantially equalized gain across a standardized wavelength grid of the signal;
• a periodic grating provided in lateral juxtaposition and longitudinally coextensive to the GC-SOA active region to generate a gain clamped signal;
• an arrayed waveguide grating (AWG) optically coupled to receive the amplified, multiplexed channel signal;
• the AWG having a wavelength grid with a passband substantially matching the standardized wavelength grid and demultiplexing the channel signals;
• the AWG having a plurality of optical waveguides at its output to respectively receive a demultiplexed channel signal;
• each of the AWG output waveguides having an integrated photodetector for detecting the optical signal and providing a corresponding electrical signal.

A monolithic receiver photonic integrated circuit (RxPIC) InP-based chip comprising:

• a semiconductor laser amplifier integrated at the input of the chip to receive a multiplexed channel signal and provide substantially equalized gain across a standardized wavelength grid of the signal;
• an arrayed waveguide grating (AWG) optically coupled to receive the amplified, multiplexed channel signal;
• the AWG having a wavelength grid with a passband substantially matching the standardized wavelength grid and demultiplexing the multiplexed channel signal;
• the AWG having a plurality of optical waveguides at its output to respectively receive a demultiplexed channel signal;
• each of the AWG output waveguides having an integrated photodetector for detecting the optical signal and providing a corresponding electrical signal;
• said chip further comprising a plurality of semiconductor laser amplifiers formed at the input of the chip to receive multiplexed channel signals and coupled to the first order Brillouin zone of the input of the AWG as a vernier wherein one of said semiconductor laser amplifiers is selected having the optimum performance response for the AWG.

A monolithic receiver photonic integrated circuit (RxPIC) InP-based chip comprising:

• an AWG optically coupled to receive a multiplexed channel signal from an optical link via an input of the chip and having a wavelength grid with a passband substantially matching a standardized wavelength grid and comprising a demultiplexer of channel signals,
• a plurality of optical waveguides at its output to each respectively receive a demultiplexed channel signal;
• a first photodetector integrated in each of the AWG output waveguides for detection of a demultiplexed optical channel signal and providing a corresponding electrical channel signal;
• at least one second photodetector integrated on the RxPIC chip and not integrated in any AWG output waveguide for detection of optical noise in the RxPIC chip and providing a corresponding electrical noise signal;
• and
• a transimpedance circuit for amplifying each of the electrical channel signals, each of the transimpedance amplifiers having a differential input where one input receives a respective electrical channel signal and the other input receives the electrical noise signal so that the on-chip optical noise is cancelled from the electrical channel signal.

A method of improving the performance of a monolithic receiver photonic integrated circuit (RxPIC) chip, comprising the steps of:

• providing a RxPIC chip that has a plurality of waveguide inputs to an on-chip demultiplexer, the demultiplexer having a plurality of integrated waveguides outputs each including an integrated photodetector;
• providing an integrated semiconductor optical amplifier (SOA) in at least some of the inputs;
• inserting a multiplexed channel signal in each of the SOA inputs and determining the response of the demultiplexed signals at the photodetectors;
• and
• selecting the SOA input having the best response as the input of choice for multiplexed channel signals provided to the RxPIC.

An optical receiver photonic integrated circuit (RxPIC) comprising:

• a single monolithic chip having a plurality of inputs to receive a multiplexed channel signal with wavelengths within an optical signal wavelength grid from an optical telecommunication source;
• a semiconductor optical amplifier (SOA) integrated in at least some of the inputs of the chip;
• the chip inputs optically coupled through a waveguide to an input of an optical demultiplexer, one of the input SOAs with the best performance selected to receive the multiplexed channel signal for amplification;
• the optical demultiplexer integrated in the chip and optically coupled to the inputs to receive the amplified, multiplexed channel signal from the selected SOA and provide the individual channel signals on respective output waveguides from the optical demultiplexer;
• and
• a plurality of photodetectors integrated in the chip and each optically coupled to one of the output waveguides to receive a demultiplexed channel signal and convert it to an electrical signal.