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) system includes a monolithic semiconductor chip having an input to receive a WDM combined channel signal comprising a plurality of optical channel signals of different wavelengths. A chip-integrated decombiner is coupled to the chip input to receive the WDM combined channel signal and separate the same into a plurality of different channel signals having different wavelengths. An array of integrated photodetectors, also integrated on the chip, each receive a separated channel signal and together provide a plurality of electrical signals representative of the optical channel signals. An electronic amplifier receives and amplifies the electrical signals. An electronic dispersion equalization (EDE) circuit is coupled to receive and adjust the amplified electrical signals for timing errors due to imperfect clock recovery of said electrical signals. An clock and data recover (CDR) circuit recovers a signal clock and data signals from the electrical signals.

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 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.

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.

Abstract: A laser source or a plurality of laser sources in a photonic integrated circuit (PIC) are provided with an electrical contact that is either segmented or is connected to a series of vernier resistor segments for supply of current to operate the laser source. In either case, at least one segment of the laser contact or at least one vernier resistor segment can be trimmed in order to vary the amount of current supplied to the laser source resulting in a change to its current density and, thus, a change in its operational wavelength while maintaining the current supplied to the laser source constant.

Abstract: A method of operating an array of laser sources integrated as an array in a single monolithic chip where the steps include designing the laser sources to have different target emission wavelengths so that together they form a spectral emission wavelength grid, coupling outputs from the laser sources to an array of gain/loss elements also integrated on the single monolithic chip, one each receiving the output from a respective laser source; and adjusting the outputs with the gain/loss elements so that the power levels of the laser source array across are substantially uniform.

Abstract: An optical probe and a method for testing an optical chip or device, such as an photonic integrated circuit (PIC), to provide for testing of such devices or circuits while they are still in their in-wafer form and is accomplished by using a an optical probe for interrogation of the circuit where an access is provided in the wafer to one or more of such in-wafer devices or circuits. As one example, the interrogation may be an interrogation beam provided at the access input to the in-wafer device or circuit. As another example, the interrogation may be an optical pickup from the access input to the in-wafer device or circuit.

Abstract: A method and apparatus operates an array of laser sources as an integrated array on a single substrate or as integrated in an optical transmitter photonic integrated circuit (TxPIC) maintaining the emission wavelengths of such integrated laser sources at their targeted emission wavelengths or at least to more approximate their desired respective emission wavelengths. Wavelength changing elements may accompany the laser sources to bring about the change in their operational or emission wavelength to be corrected to or toward the desired or target emission wavelength. The wavelength changing elements may be comprise of temperature changing elements, current and voltage changing elements or bandgap changing elements.

Abstract: A method of tuning optical components integrated on a monolithic chip, such as an optical transmitter photonic integrated circuit (TxPIC), is disclosed where a group of first optical components are each fabricated to have an operating wavelength approximating a wavelength on a standardized or predetermined wavelength grid and are each included with a local wavelength tuning component also integrated in the chip. Each of the first optical components is wavelength tuned through their local wavelength tuning component to achieve a closer wavelength response that approximates their wavelength on the wavelength grid.

Abstract: A method of operating an array of integrated laser sources formed as an integrated array on a single substrate in a photonic integrated circuit (PIC) where the laser sources are designed for operation at different targeted emission wavelengths which, in toto, at least approximate a grid of spatial emission wavelengths. A first wavelength tuning element is associated with each laser source and is adjusted over time so that each laser source maintains its targeted emission wavelength. As an alternative, the drive current to each laser source may be initially set so that each laser source operates at its targeted emission wavelength. Thereafter, adjustments to retune the laser sources to their targeted emission wavelengths are accomplished by the first wavelength tuning elements. The outputs of the laser sources may be combined via an optical combiner to produce a single combined output from the PIC.

Abstract: A weighted device that attaches to a baseball or softball bat for the purpose of increasing the bat's mass during batting practice thereby increasing a persons strength and improving their bat control, ultimately improving their batting average and batting power. The device can be used during the actual practice of hitting a ball. The device can be attached to the bat at various locations along the tapered portion of the bat.

Abstract: An optical amplification system directs a diffraction-limited signal beam through a series of approximately 90.degree. crossings with a number of non-diffraction-limited pump beams in a photorefractive medium. All of the beams are s-polarized, resulting in an energy transfer from the pumps to the signal beam while leaving the signal beam diffraction-limited. The photorefractive medium is preferably a series of BaTiO.sub.3 :Rh crystals that receive the pump and signal beams through orthogonal faces, with their C-axes at approximately 45.degree. to both beams. A binary tree optical distribution network is used to minimize waveguide splits in forming a large number of pump beams.

Abstract: A method of making semiconductor laser arrays having an impurity disordered pattern of waveguides at least some of which are directly joined at branching junctions. The region near the branching junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. Using one impurity dose and one disordering depth in a first portion of the pattern and another in a second portion of the pattern provides a combination of strong and weak waveguiding with strong waveguides that eliminate evanescent coupling from occurring at least in the branching junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output.

Abstract: A semiconductor laser array having a plurality of waveguides at least some of which are directly joined at Y-junctions. The region near the Y-junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. A combination of strong and weak waveguiding is provided, with strong waveguides that eliminate evanescent coupling from occuring at least in the Y-junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output. Alternatively, even without evanescent coupling, the modes can adjust their phases in the weak waveguides, where the propagation constant is less tightly specified by the geometry.

Abstract: A phased array laser having a laterally asymmetric variation in the gain or coupling of lasing elements of the array for emission in a single far field lobe. The lasing elements are confined by internal waveguide structuring, periodically spaced current confinement stripes, or by a hybrid of both waveguiding and current confinement. The widths, lengths, depths, or separations of the waveguides or stripes vary laterally across the array to affect the gain or coupling of the lasing elements. Alternate embodiments introduce lateral asymmetry in the active region or other layer thicknesses, doping, mirror facet reflectivities, A1 content of the layers, heat dissipation, or thicknesses of electrical contacts. The laterally asymmetric variations may be linear or nonlinear, monotonically increase from one edge to the other edge, or may be such that the relevant parameter is greatest or least in the center of the array.

Abstract: A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

Abstract: A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.