Abstract: A high capacity optical transmitter implemented on a photonic integrated circuit chip comprises a single light source which supplies a continuous wave having a particular wavelength to a plurality of modulators to form modulated optical information signals. A phase shifter is coupled to at least one of the modulators and is used to shift the phase of the corresponding modulated optical information signal associated with a particular modulator. A polarization beam combiner receives each of the modulated optical information signals from the modulators and the modulated optical information signal from the phase shifter and combines each of these signals to form a polarization multiplexed differential quadrature phase-shift keying signal. The light source, the plurality of modulators, the phase shifter and the polarization beam combiner are all integrated on the chip.

Abstract: An optical transmitter comprises a monolithic transmitter photonic integrated circuit (TxPIC) chip that includes an array of modulated sources formed on the PIC chip and having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. A wavelength selective combiner is formed on the PIC chip having a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. The signal outputs of the modulated sources optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. A first wavelength tuning element coupled to each of the modulated sources and a second wavelength tuning element coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to the wavelength selective combiner to sample the combined signal output.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: Consistent with the present disclosure, optical devices are provided along different optical paths in a photonic integrated circuit (PIC). The optical components have different optical losses associated therewith so that optical signals propagating in the optical paths have desired power levels, which may be uniform, for example.

Abstract: An optical equalizer/dispersion compensator (E/CDC) comprises an input/output for receiving a multiplexed channel signal comprising a plurality of channel signals of different wavelengths. An optical amplifier may be coupled to receive, as an input/output, the multiplexed channel signals which amplifier may be a semiconductor optical amplifier (SOA) or a gain clamped-semiconductor optical amplifier (GC-SOA). A variable optical attenuator (VOA) is coupled to the optical amplifier and a chromatic dispersion compensator (CDC) is coupled to the variable optical attenuator. A mirror or Faraday rotator mirror (FRM) is coupled to the chromatic dispersion compensator to reflect the multiplexed channel signal back through these optical components The E/CDC components may be integrated in a photonic integrated circuit (PIC) 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. The method includes the steps of decombining 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 optical receiver can be monitored again to determine if an acceptable level for the BER has been achieved by the previous chirp adjustment.

Abstract: Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: A photonic integrated circuit that includes a plurality of active and passive components on a substrate where one of the components is an optical combiner/decombiner having at least one free space coupler region and a plurality of longitudinal ridge waveguides each extending in the circuit from a first region of the waveguide and coupled at a second region of the waveguide at the free space coupler region. A first dielectric layer formed over the ridge waveguides and the free space coupler region. The first dielectric layer monotonically increases in cross-sectional thickness from the waveguide first region to the second region to reduce signal insertion losses in transitioning from the ridge waveguides to the free space coupler region. The first dielectric layer may be covered with a second passivation layer. The first dielectric layer may be SiOx, SiNx or SixONy and the second passivation layer may be BCB, ZnS or ZnSe.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: Devices and techniques for fabricating InAlGaN light-emitting devices are described that result from the removal of light-emitting layers from the sapphire growth substrate. In several embodiments, techniques for fabricating a vertical InAlGaN light-emitting diode structure that result in improved performance and or cost-effectiveness are described. Furthermore, metal bonding, substrate liftoff, and a novel RIE device separation technique are employed to efficiently produce vertical GaN LEDs on a substrate chosen for its thermal conductivity and ease of fabrication.

Abstract: An optical transmitter comprises an array of modulated sources having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. Signal outputs of the modulated sources are optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. The wavelength selective combiner has a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. A first wavelength tuning element is coupled to each of the modulated sources and a second wavelength tuning element is coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to receive a sampled portion the combined signal output from the wavelength selective combiner. A wavelength control system is coupled to the first and second wavelength tuning elements and to the wavelength monitoring unit to receive the sampled portion of the combined signal output.

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: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An optical transmitter comprises a monolithic transmitter photonic integrated circuit (TxPIC) chip that includes an array of modulated sources formed on the PIC chip and having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. A wavelength selective combiner is formed on the PIC chip having a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. The signal outputs of the modulated sources optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. A first wavelength tuning element coupled to each of the modulated sources and a second wavelength tuning element coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to the wavelength selective combiner to sample the combined signal output.

Abstract: A single monolithic transceiver chip for handling optical to electrical to optical conversion of optical WDM signals in an optical transmission network which has an optical WDM signal input for reception of a WDM signal and an optical WDM signal output for transmission of a WDM signal and a plurality of electrical signal outputs and a plurality of electrical signal inputs. The chip further comprises an integrated decombiner coupled to the optical signal input that separates the WDM signal into a plurality of separate optical channel signals, an integrated array of photodetectors that each receives a respective optical channel signal and that converts the optical channel signal into an electrical signal and that provides the converted electrical signals to the electrical signal outputs of the transceiver chip.