Abstract: A method and article for monitoring and controlling power drift in the output of a diode array is described. The diode array is used, for example, as a light pump for a fiber laser. In one embodiment, an improved fiber laser includes the light pump, which launches light into a laser cavity. The fiber laser further includes a sampler operable to receive at least a portion of the light before it is launched into the laser cavity. The sampled portion represents a known fraction of the total light signal generated by the light pump. In some embodiments, the sampled light is directed, via the sampler, to a photodetector. The photodetector converts the sampled light into a first electrical signal and delivers it to a processor. The processor is operable to compare the electrical signal with a set-point signal representative of a desired power output of the sampled portion of the launched light.

Abstract: A device is provided for cleaving semiconductor products or the like. The device may be formed of an inlet for receiving pressurized gas, an adjustable slot for directing the gas toward the products, and a movable flow control member. According to one aspect of the invention, the flow control member is located within a housing that also defines the inlet and the adjustable slot. A cover may be located on the front of the housing. The cover may have a lower edge that forms one side of the slot. The other side of the slot may be formed by the movable flow control member. The cleave device may have an uncomplicated, compact construction. The cleave device may be operated with a flexible product handling system. That is, the brittle products may be handled within opposed flexible sheets. The sheets may be used to locate the products over a ledge (a cleaving position) where they are bent to cause cleaving along crystal planes initiated at scribe or score lines.

Abstract: A Michelson interferometer optical mirror switch is formed to include an optical signal path adjustment arrangement to transform the switch between a first, “pass through” state and a second, “reflective” state. A pair of input optical signal paths are coupled into an optical beam splitter that thereafter directs 50% of each optical signal toward a mirror element. The reflected signals then pass back through the beam splitter. If the optical path lengths are equal, an optical signal entering a first signal port will be coupled into a second signal port (the “pass through” state). If the optical path lengths differ by an odd, half-wavelength amount, the reflected signals will be directed back into the optical signal port of origin (the “reflective” state).

Abstract: A hybrid integrated optical transmitter comprising a wavelength selectable laser (WSL) source coupled to an optical amplifier/modulator has been realized. Disposed between the optical combiner and the optical amplifier/modulator is an “optical isolator.” The optical isolator includes at least a Faraday rotator and, either solely or in combination with a single polarizer and/or half-wave plate is used to selectively rotate and pass polarized light egressing from the wavelength selectable laser source. Optical isolation is achieved by the egressing radiation from and back reflections incident on the laser source being at two mutually exclusive orthogonal polarization states or by the reflections being totally extinguished. Advantageously, the laser source is unresponsive to orthogonally polarized light, and hence any unwanted back reflections do not substantially affect the operating characteristics of the laser(s).

Abstract: A wavelength demultiplexer having at least two pairs of photodetectors is disclosed. The photodetectors are arranged in sequential layers along an optical path and the pairs of photodetectors are separated by a non-optically active insulator interposed between the pairs. The photodetectors differ in bandgap, and are arranged so that the optical signal passes through relatively larger bandgap photodetectors before being received by relatively smaller bandgap detectors. Each photodetector absorbs photons within a predetermined energy range and generates a voltage as a function of the absorbed energy. The photodetectors can be used to detect, and hence demultiplex, a wavelength-division-multiplexed signal.

Abstract: A wavelength stabilized laser system includes a laser that produces a laser light having an amplitude and a wavelength that varies as a function of a temperature of the laser. A temperature control device controls the temperature of the laser. A beam splitter deflects a portion of the laser light. A first detector receives the portion of the laser light from the beam splitter and provides a first signal representing the amplitude of the laser light. A filter has a gain that is a function of the wavelength of the laser light. The filter receives the laser light and outputs a filtered light having an amplitude that varies with the wavelength of the laser light. A second detector provides a second signal representing the amplitude of the filtered light. A sealed housing contains the laser, the first and second detectors and the filter. The housing has a window.

Abstract: An apparatus is provided for cleaving a laser bar into semiconductor chips. The apparatus includes a supporting structure on which a member slides. The apparatus also includes a pair of film layers. The laser bar is positioned between the film layers. A chamber is sealed to the top film layer. The chamber has an inlet through which gas is input. The movement of the member and the downward force caused by the buildup of gas pressure in the chamber induce cleaving of the laser bar at predetermined locations. The laser bar may have score marks at the predetermined locations to produce weak points. Pressure pulses may be coordinated with the movement of the member to break the laser bar at the desired locations.

Abstract: Methods and apparatus for determining channel signal bit rate and measuring channel signal performance in a wavelength division multiplexed (WDM) optical network or other optical communication system. A selected channel signal modulated by a pseudorandom non-return-to-zero (NRZ) data stream is detected in a front-end receiver or photodetector and converted to an electrical signal. An autocorrelator receives the detected channel signal, and generates an autocorrelation function for the corresponding electrical signal, from which the channel signal bit rate can be determined. The autocorrelator separates the electrical signal into a first part and a second part, introduces a delay between the first and second parts, multiplies the first and second parts in a multiplier, and integrates the result of the multiplication over a designated time period to provide the autocorrelation function. The bit rate may be determined by measuring the width of a peak in the autocorrelation function.

Abstract: A method for pivoting an optical device about one or more axes thereof is disclosed. Springs couple the optical device to the micro-electro-mechanical structure. A portion of the springs are fastened on the micro-electro-mechanical structure. Fastening the portion of each spring on the electromechanical structure prevents the springs from moving the optical device in a translational direction when such optical device pivots about the one or more axes.

Abstract: A process for fabricating a waveguide with a desired tapered profile is disclosed. The waveguide has a first section with a first height and a second section with a second height. The first height is greater than the second height. The waveguide height tapers from the first height to the second height. The waveguide is a compound semiconductor material and is formed using selective area growth. In selective area growth, a dielectric mask is formed on a substrate. The dimensions of the dielectric mask are selected to provide a waveguide with the desired dimensions. The compound semiconductor material is deposited on the substrate using chemical vapor deposition. The dielectric mask affects the rate at which the compound material is deposited in areas of the substrate proximate to the mask. Therefore, the profile of the waveguide formed using the selected mask dimensions is modeled and compared with the desired profile.

Abstract: A direct detector uses optical amplification and resistors to eliminate the need for linear electrical amplifiers. The receives evenly splits an input light wave along a clock path and a data recovery path. Along the clock path a first photodetector detects the light wave. The input power induces a current across a first resistor in series with the photodetector giving rise to a voltage V which becomes the input voltage to the cock recovery device. The output from the clock recovery device is then split by an optical power splitter with one output to a decision circuit and another output optionally available for external use. Along the data path the light wave is split a second time and each of the two resultant paths are detected by a photodetector in series with a resistor. The decision circuit has input pins from each of the photodetectors to provide the data signal and its average DC voltage in lieu of the complement of the data signal as inputs to the decision circuit.

Abstract: An apparatus and method for performing tests on laser chips that are not labor intensive and will not result in wasted parts should the laser chip fail the test is disclosed. A “bare” laser chip is subjected to a test in accordance with one embodiment by placing the laser chip on an insulating material with an embedded conducting contact through which the current to power the laser chip is passed. A cover plate provides a channel around the laser chip through which a jet of high pressure inert gas is passed to dissipate the self-heating of the laser chip that occurs during the test process. The laser chip is kept in place by physical pressure. In accordance with another embodiment, the temperature of the laser chip is measured and a thermoelectric cooler is used to cool the laser chip. The test on the “bare” laser chip eliminates the need to solder bond the laser chip to a carrier and attach wire bonds to the laser chip, thus reducing associated labor and parts costs.

Abstract: An optical fiber cable connector assembly comprising two connectors each of which is comprised of a rigid inorganic body which is coated with an organic layer into which grooves are formed which are adapted to restrain the ends of two fiber optic cables. One connector is adapted to fit over the other when inverted to form the assembly with one or more fiber optic cables restrained between them.

Abstract: A coating fixture adapted to extricate a jammed connector web is described. The coating fixture includes a pair of vertical supports. Each support has a first portion spaced apart from a second portion. Springs are placed between the first and second portions to allow movement of the first portions relative to the second portions. The second portions may be anchored to prevent their movement.

Abstract: An LED device that emits light in a pattern is disclosed. The LED device is a layer of active material that is sandwiched between a transparent substrate with an anode formed thereon and a cathode. The active material has a layer of light emitting material that emits light when electron/hole recombination is induced in the material. The patterned emission is defined by a patterned layer in the active material of the LED device. The patterned layer has at least a first thickness and a second thickness. When the device is on, the portion of the device associated with the first thickness of the patterned layer is visually distinct from the portion of the device that is associated with the second thickness of the patterned layer.

Abstract: An optical package includes a dual fiber termination having a first optical fiber end portion and a second optical fiber end portion. A collimating lens, spaced from the dual fiber termination, is configured for collimating and transmitting an optical signal emitted from the first optical fiber end portion and for converging a reflected optical signal onto the second optical fiber end portion. A mirror spaced from the collimating lens and having a reflective layer is configured and oriented for reflecting at least a portion of the emitted optical signal from the collimating lens back toward the collimating along a propagation path. A compensation lens is disposed between the collimating lens and the reflective layer of the mirror for correcting optical misalignment between the dual fiber termination and the collimating lens.

Abstract: An optical isolator which is suitable for array assembly and may be produced by lithographically-defined means comprises a sandwich of layers. These layers include a substrate having two waveguides for transmission of a signal having two parts, each part being comprised of two rays; a walk-off plate for spatially displacing or recombining the rays of both parts; a half-wave plate of birefringent material for reciprocal rotation of the polarization of the rays of only one part of the signal; a non-reciprocal rotator for rotating the polarization of the rays of both parts of the signal at a predetermined angle; a lens for collimating the rays transmitted through the walk-off plate, the half-wave plate, and the rotator, and for focusing the rays opposite the rotator at a common region along an end surface; and an end surface for interconnection of the rays of the two parts of the signal.

Abstract: A system is provided for partially or completely offsetting optical fiber amplifier gain spectrum variations due to temperature by setting the optical pump signal leading into the amplifier to a desired wavelength value. Optical fiber amplifiers have gain spectrum variations associated with temperature and gain spectrum variations associated with the optical pump signal wavelength. By controlling the optical pump signal wavelength supplying the amplifier, the optical fiber amplifier gain variations due to temperature can be partially or completely offset, which helps minimize total amplifier spectral gain variations. The invention is applicable to dense wavelength division multiplexing (DWDM) systems.

Abstract: A wavelength-stabilized laser system includes a laser that produces a laser light. The laser light has an amplitude and a wavelength that varies with the temperature of the laser and/or a bias signal provided to the laser. A temperature control device controls the temperature of the laser. A first detector outputs a first signal representing an amplitude of a laser light. A filter receives the laser light and outputs a filtered light having an amplitude that varies with the wavelength of the laser light. A second detector outputs a second signal representing the amplitude of the filtered light. An electromagnetic radiation source transmits electromagnetic radiation through the filter and through a diverging lens. A third detector receives the electromagnetic radiation that passes through the diverging lens. The second detector may be between the diverging lens and the third detector. The third detector outputs a third signal representing an amplitude of the electromagnetic radiation.

Abstract: A demultiplexer demultiplexes an incoming WDM signal that contains a given number of channels into a given number of bands, each band containing a subset of the number of channels. An add/drop filter capable of handling the subset of channels in each band is coupled to the demultiplexer when a channel within a band requires further processing. A multiplexer multiplexes the processed bands and the passed through bands and outputs a WDM signal into the optical network.