Abstract: A photonic integrated circuit (PIC) for a PON transceiver comprises a single monolithic chip having a modulated transmitter laser diode of a first wavelength, ?1, for generating a first communication signal outgoing from the chip via an input/output port and a receiving photodetector for receiving a second communication signal of a second wavelength, ?2, onto chip incoming from the input/output port and a monitoring photodetector for receiving a portion of the first communication signal to monitor the laser diode output power. In one embodiment, the chip is provided with multimode (MM) coupler set to direct a substantial portion of the incoming communication signal to the receiving photodetector and to direct a substantial portion of the outgoing communication signal to the input/output port. A filter may be inserted before the receiving photodetector and/or the laser diode to extract any remaining and undesired signal to either such electro-optic elements.

Abstract: An optical transport network comprises a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip and a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip.

Abstract: An InP-based photonic integrated circuit (PIC) includes an optical passive element in the circuit with no bias current applied to such an element. A passivation cladding layer overlies a surface of the optical passive element where the passivation layer comprises benzocyclobutene polymer or BCB.

Abstract: A method of in-wafer testing is provided for a monolithic photonic integrated circuit (PIC) formed in a semiconductor wafer where each such in-wafer circuit comprises two or more integrated electro-optic components, one of each in tandem forming a signal channel in the circuit. The method includes the provision of a first integrated photodetector at a rear end of each signal channel and a second integrated photodetector at forward end of each signal channel. Then, the testing is accomplished, first, by sequentially operating a first of a selected channel electro-optic component in a selected circuit to monitor light output from a channel via its first corresponding channel photodetector and adjusting its operating characteristics by detecting that channel electro-optic component output via its second corresponding channel photodetector to provide first calibration data.

Abstract: A coolerless photonic integrated circuit (PIC), such as a semiconductor electro-absorption modulator/laser (EML) or a coolerless optical transmitter photonic integrated circuit (TxPIC), may be operated over a wide temperature range at temperatures higher then room temperature without the need for ambient cooling or hermetic packaging. Since there is large scale integration of N optical transmission signal WDM channels on a TxPIC chip, a new DWDM system approach with novel sensing schemes and adaptive algorithms provides intelligent control of the PIC to optimize its performance and to allow optical transmitter and receiver modules in DWDM systems to operate uncooled. Moreover, the wavelength grid of the on-chip channel laser sources may thermally float within a WDM wavelength band where the individual emission wavelengths of the laser sources are not fixed to wavelength peaks along a standardized wavelength grid but rather may move about with changes in ambient temperature.

Abstract: A method is disclosed for optimizing optical channel signal demultiplexing in a monolithic receiver photonic integrated circuit (RXPIC) chip by providing an integrated channel signal demultiplexing with multiple waveguide input verniers provided to an WDM signal demultiplexer. The RxPIC chip may optionally include an integrated amplifier in at least some of the waveguide input verniers. The RxPIC chip may be comprised of, in monolithic form, a plurality of optional semiconductor optical amplifiers (SOAs) at the input of the chip to receive a WDM signal from an optical link which is provided along a plurality of waveguide input verniers to an integrated optical demultiplexer, such as, but not limited to, an arrayed waveguide grating (AWG), as a WDM signal demultiplexer. Thus, optical outputs from the respective semiconductor laser amplifiers are provided as vernier inputs to the optical demultiplexer forming a plurality of input verniers at the input to the optical demultiplexer.

Abstract: An optical-to-electrical-to-optical converter comprises a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip comprising an optical waveguide formed in the chip from a chip input to receive a first multiplexed channel signal from an optical link and provide them to an arrayed waveguide grating (AWG) which demultiplexes the multiplexed channel signals and provides a plurality of electrical channel signals to an electronic regenerator. The regenerator regenerates the electrical channel signals to an original signal waveform and provides the reformed electrical signals to a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip having an array of modulated sources formed in the chip that are coupled as inputs to an arrayed waveguide grating (AWG). The TxPIC modulates the reformed electrical signals to form a plurality of optical channel sign which are combined to form a second first multiplexed channel signal for transmission on an optical link.

Abstract: An optical transport network comprises a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip and a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip.

Abstract: A method is disclosed for monitoring and controlling the bit error rate (BER) in an optical communication network where an optical receiver in the optical transmission network is a monolithic photonic integrated circuit (RxPIC) chip. The method includes the steps of decombining on-chip a combined channel signal received from the network and then monitoring a real time bit error rate (BER) of a decombined channel signal. The determined BER is then communicated, such as through an optical service channel (OSC) to an optical transmitter source that is the source of origin of the channel signal. Based upon the determined BER, the chirp of a channel signal modulator at the optical transmitter source that generated the monitored channel signal is adjusted by, for example, adjusting its bias. The same channel signal received at the RxPIC chip can be monitored again to determine if an acceptable level for the BER has been achieved by the previous chirp adjustment.

Abstract: An optical receiver photonic integrated circuit (RxPIC) comprises a semiconductor monolithic chip having an input to receive from an optical transmission link a combined channel signal originating from an optical transmitter source and comprising a plurality of channel signals having different wavelengths forming a wavelength grid. An optical decombiner is integrated in the chip and optically coupled to the input to receive the multiplexed channel signal and provide a decombined individual channel signal on an output waveguide of a plurality of such output waveguides provided from the optical decombiner. A plurality of photodetectors are also integrated in the chip and each photodetector is optically coupled to one of the output waveguides to receive a decombined channel signal and convert the channel signal to an electrical signal.

Abstract: An optical transmitter photonic integrated circuit (TxPIC) comprises a semiconductor monolithic chip with a plurality of optical signal channels where each channel comprises a modulated signal source. The output from the modulated signal sources are coupled to an input of an integrated optical combiner to form a WDM output signal for transmission off the TxPIC chip to an optical transmission link. An optical service channel (OSC) is also integrated on the TxPIC chip to receive a service signal from the optical receiver source which is also coupled the optical transmission link.

Abstract: A photonic integrated circuit (PIC) comprises a plurality of integrated optically coupled components formed in a surface of the PIC and a passivating layer overlies at least a portion of the PIC surface. The overlying passivating layer comprises a material selected from the group consisting of BCB, ZnS and ZnSe. Also, when the circuits are PIC chips are die in the semiconductor wafer, a plurality of linear cleave streets are formed in a wafer passivation layer where a pattern of the cleave streets define separate PIC chips in the wafer for their subsequent singulation from the wafer.

Abstract: A method for reducing insertion loss in a transition region between a plurality of input or output waveguides to a free space coupler region in a photonic integrated circuit (PIC) includes the steps of forming a passivation layer over the waveguides and region and forming the passivation overlayer such that it monotonically increases in thickness through the transition region to the free space coupler region.

Abstract: Disclosed is a method of in-wafer testing of integrated optical components and in-wafer chips with photonic integrated circuits (PICs).

Abstract: A method for forming and apparatus comprising a free space coupler region having a plurality of optical waveguides coupled to the space coupler region at an interface region, the waveguides converging with one another to the interface region, and a trench formed between adjacent waveguides, the depth of the trench or trenches extending from an outer point to the interface region and monotonically decreasing in depth from the outer point to the interface region.

Abstract: An arrayed waveguide grating (AWG) comprises at least two free space regions, a plurality of grating arms extending between the two space regions, a passivation layer formed over the arrayed waveguide grating and a plurality of inputs at least to one of the free space regions to receive a plurality of channel signals separated by a predetermined channel spacing. A depth of the passivation layer chosen by providing a TE to TM wavelength shift between TE and TM modes propagating through the arrayed waveguide grating being approximately less than or equal to 20% of a magnitude of the channel spacing.

Abstract: A method of in-wafer testing is provided for a monolithic photonic integrated circuit (PIC) formed in a semiconductor wafer where each such in-wafer circuit comprises two or more integrated electro-optic components, one of each in tandem forming a signal channel in the circuit. The method includes the provision of a first integrated photodetector at a rear end of each signal channel and a second integrated photodetector at forward end of each signal channel. Then, the testing is accomplished, first, by sequentially operating a first of a selected channel electro-optic component in a selected circuit to monitor light output from a channel via its first corresponding channel photodetector and adjusting its operating characteristics by detecting that channel electro-optic component output via its second corresponding channel photodetector to provide first calibration data.

Abstract: Method and apparatus for utilizing a probe card for testing in-wafer photonic integrated circuits (PICs) comprising a plurality of in-wafer photonic integrated circuit (PIC) die formed in the surface of a semiconductor wafer where each PIC comprises one or more electro-optic components with formed wafer-surface electrical contacts. The probe card has a probe card body with at least one row of downwardly dependent, electrically conductive contact probes. The probe body is transversely translated over the surface of the wafer to a selected in-wafer photonic integrated circuit (PIC) die. Then, the contact probes of the probe card are brought into engagement with surface electrical contacts of the selected photonic integrated circuit (PIC) die for testing the operation of electro-optic components in the selected in-wafer photonic integrated circuit (PIC) die.

Abstract: A method of calibrating a monolithic transmitter photonic integrated circuit (TxPIC) chip is disclosed where the chip contains integrated arrays of laser sources and electro-optic modulators forming a plurality of different wavelength signal channels where each laser source on the chip is sequentially selected and tested for the output power and operational wavelength. Calibration data is initially determined by checking an amount of output power of each laser output and any offset of each laser operational wavelength from a desired predetermined value. Then, adjustment of the operational wavelength of each laser source is accomplished to substantially match the desired predetermined value. The laser source output power and operational wavelength may then be rechecked to determine if there is any remaining offset of each laser operational wavelength from the desired predetermined value.

Abstract: A photonic integrated circuit (PIC) chip with a plurality of electro-optic components formed on a major surface of the chip and a submount that includes a substrate that extends over the major surface of the chip forming an air gap between the substrate and the major surface, the substrate to support electrical leads for electrical connection to some of the electro-optic components on the chip major surface.