Abstract: In the system of the present invention, two DFB laser outputs are combined in a first stage to produce a beat signal. The two main channels interfere with each other to form beat signals. This combined signal is then used as the seed to create multi-channels through optical fiber non-linearity in a multiplier stage.

Abstract: There is disclosed a process for melting a luminescent oxygen sensitive compound into extruded polymer films. Specifically, there is disclosed a process for thermal melting of oxygen-sensitive indicators into common packaging polymers used for commercial packaging of products, such as foods. The oxygen-sensitive indicators can be used for real-time monitoring of oxygen in commercial packaging operations.

Abstract: In this invention an optical gain element is used where a fraction of the optical output signal is passed through a periodic filter and fed back to the gain medium. This configuration simply forms a multi-wavelength ring laser. The optical gain element provides the gain medium for the laser and the filter forces the laser to lase on the predetermined wavelengths. The periodic filter can simply be an asymmetric Mach-Zehnder Interferometer (MZI). It is known that asymmetric MZIs have an almost sinusoidal wavelength response where its period is a function of the length difference of the arms of the asymmetric MZI. Therefore, channel spacing may be controlled by changing the arms length difference in an Asymmetric MZI.

Abstract: The present invention introduces a novel and simple method to adjust the MZ filter channels to those of the ITU grid. This is done through inducing an optical path length difference by using a UV light source to create a change in the index of refraction of the fiber arms after the device is packaged. The UV light is launched into the MZI filter through one of its input ports in order to achieve the phase adjustment. Since the exposure length is the entire length of one of the arms of the MZI, the required refractive index change is much smaller than the localized UV tuning of the previous methods. This allows for a weaker UV source power and shorter treatment times, thus reducing the chances of localized fiber damage.

Abstract: A Mach-Zehnder interferometer having two optical couplers interconnected by two optical fibers at least one of which is temperature insensitive. In use, temperature induced changes in the geometrical length and refractive index of the temperature insensitive fibers offset each other so that the optical path length of the fiber is unaffected by the temperature change. Where two temperature insensitive fibers are included these may be of the same or of different lengths. The interferometer may be used in a Dense Wavelength Division Multiplex system.

Abstract: In a method for detecting impurities in a transparent material, the material (2) is scanned line by line and the light transmission through the material is measured and compared with a reference value. If the transmission value at one point of the material is in a predetermined relation to said reference value, indicating the occurrence of impurities, the light transmission is studied in an area around the measured point for this transmission value in order to determine the extent and shape of the impurity, the light transmission values in the central area of the impurity being compared with transmission values measured in surrounding parts of the impurity to determine whether the impurity is of gel type or an impurity of some other type.

Abstract: A method of making an asymmetric Mach-Zehnder Interferometer (MZI) adjusts the length of the arms of two Michelson Interferometers, (MI) to achieve desired wavelength response then combines the MIs to provide the MZI. An asymmetric MZI is, therefore, provided which comprises two asymmetric MIs optically connected back-to-back.

Abstract: WDM demultiplexers are provided utilizing, for example, cascaded asymmetric MZI filters, wherein the (asymmetric) differential delay is such that at the output of the first stage MZI demultiplexes the WDM channels in groups of two at its output. The result is a relaxed specification for the frequency response of the filters.

Abstract: An optical amplifier for two adjacent bands of optical data channels provides gain across the entire spectrum, including the so-called dead-band, by splitting the entire input signal equally into two paths. One path is optimized to amplify one band and the other path is optimized to amplify the other. An optical delay in one path, usually the one optimized for the lower wavelength band, ensures equal optical path lengths for the two paths. The amplified signals in that two paths are then combined to yield or flat gain profile across the two bands and the gap in-between.

Abstract: Equipment for detecting impurities in transparent material comprising a light source to illuminate the material, a camera to detect light transmitted through the material and signal-processing apparatus for processing and analysing signals from the camera representing the light transmission through the material. This type of equipment is calibrated by dark areas being displayed on a film of transparent material (22, 24, 26) and the actual sizes (30) of the areas being determined. The sizes of the dark areas are then determined using the detecting equipment (34) and in this way determined sizes are compared with actual sizes (36) for calibration of the detecting equipment (38).

Abstract: Equipment for determining the surface uniformity of film or sheet material, in which the material is arranged to pass over a rotating measuring shaft, a light source being arranged to illuminate the horizon formed by the outer surface of the material exactly where it is in contact with the periphery of the measuring shaft, and also a light detector for detecting light transmitted from the light source and emitting corresponding electric signals to subsequent signal-processing apparatus in order to determine the dimensions, number and locations of the irregularities from the shadows produced by the surface irregularities. In a method for calibrating equipment of this type, at least one calibration shaft (10, 12) is produced with a diameter corresponding to the diameter of the measuring shaft and the thickness of the material being calibrated, after which a number of elevations (No.1, No.2, No.3) are produced on the peripheral surface of the shaft and the actual dimensions of the elevations are determined.

Abstract: A plasma source comprises a thermionic emitter (2) heated by an induction coil (7), which also provides radiofrequency energy within an electrically insulated cylindrical former (1). A cylindrical anode (10) is concentric with emitter (2) and axially displaced therefrom, generating a potential difference between anode (10) and emitter (2). The potential difference between anode (2) and ground and axial magnetic fields causes the plasma to be extracted from the source. Emitter (2) is held at negative potential via a conductive support (5). Process gas is introduced near emitter (2) and a secondary gas injected in the anode space. Radiofrequency excitation of emitter (2) generates electrons via thermionic and field effects, resulting in efficient plasma generation. Both electron generation effects contribute to a broad energy spectrum of electrons, providing effective neutralisation of the plasma.

Abstract: A method and apparatus (50, 70, 90) for making a back glass substrate (24) for a plasma display panel (20) by forming hot sheet glass G heated above its annealing point and embodied either as a continuous ribbon (60) or discrete sheets (74). The hot forming provides the hot sheet glass G with gas discharge troughs (38) spaced by barrier ribs (40). The hot forming of the sheet glass G heated above its annealing point can be performed by a rotatable forming member (62) having curved projections (66) or by a press member (78) having elongated projections (84). The constructed plasma display panel (20) has a front glass substrate (22) and a back glass substrate (24) with the gas discharge trough and barrier rib construction made by hot forming above the annealing point.

Abstract: A drive system is shown for AC plasma (ACP) gas discharge flat bistable matrix panels on which real-time video and computer graphics, both with pixel by pixel gray scale are displayed. The drive scheme increases scan speed, reduces complexity, and minimizes the circuitry required to operate the video and computer graphics on the ACP display by a unique application of standard high density memory IC architecture and panel drive waveform technique applying all of the drive voltages to the ACP panel from the row (Y) axis and only selective cancellation voltage from the column (x) axis.

Abstract: An AC color plasma display system comprises an AC plasma display panel having transversely oriented first and second insulated electrode arrays defining a matrix of display pixels. Linear ribs are in substantially parallel alignment with one of the linear electrode arrays to form gas channels, respectively, aligned electrodes in one of the arrays. A plurality of phosphor layers are on the ribs, and a UV rich gas discharge medium is sealed in the channels. An interface circuit for receiving video signals from one of a selected plurality of video sources produces, in digital form, pixel data, pixel clock, and horizontal and vertical synchronizing signals from a gray scale drive system is connected between said interface circuit and AC plasma display panel. The gray scale drive system include blue, green and red color channels and pixel-by-pixel gray scale control of each color channel.

Abstract: A system and method for driving a flat panel display are provided. The system includes a register connected to a latch having outputs connected to logic circuits which correspond to the electrodes. Each logic circuit is also connected to the register, and generates control signals based on the next state and the current state of the corresponding electrode. Each logic circuit is configured such that upon an activation signal, the logic circuit control signals connect the change up driver to electrodes having a low current state and a high next state, and connect the change down driver to electrodes having a high current state and a low next state.

Abstract: A system and method for driving a plasma display panel are provided. The method includes scanning a current display line to selectively store charge quantities on selected pixels defined along a first row electrode at cross-points of corresponding column electrodes. A priming voltage pulse is applied between the first row electrode and a second row electrode to cause a priming discharge between the first and second row electrodes. The priming discharge is capable of priming a different display line proximate to the current display line. The system includes driver circuitry for scanning a current display line, and for applying the priming voltage pulse to cause the priming discharge to prime a different display line proximate to the current display line.

Abstract: A high brightness presentation display system includes:a transparent display panel having a viewing side and a non-viewing side, furcated row electrode array, furcated column electrode array defining matrix crosspoints and an electro-responsive display producing medium at said matrix crosspoints. Row electrode drive circuitry is connected to selectively drive electrodes in the row electrode array and column electrode drive circuitry is connected to selectively drive electrodes in the column electrode array such that conjoint voltages on selected row and column electrodes operate the display. The furcated electrode spacing and interelectrode spacings are such as to enhance discrimination, and the multiple sub-pixels due to the furcations of electrodes enhance brightness.

Abstract: A flat panel having at least one non-conductive substrate having a first conductor array on the surface thereof and a dielectric layer on said first conductor array having an exposed flat surface. A first predetermined pattern of vias external through the dielectric layer to pads on each conductor in the array. A second predetermined pattern of vias extend through the dielectric layer to further conductive pads, and an input and through-feed second conductor array is on the substrate with the dielectric layer covering the second predetermined pattern. A conductor material, preferably a gold frit, is in contact with the conductor at the bottom of each via, respectively, and partially filling same to a predetermined level below said exposed flat surface.

Abstract: A method and apparatus (50, 70, 90) for making a back glass substrate (24) for a plasma display panel (20) by forming hot sheet glass G heated above its annealing point and embodied either as a continuous ribbon (60) or discrete sheets (74). The hot forming provides the hot sheet glass G with gas discharge troughs (38) spaced by barrier ribs (40). The hot forming of the sheet glass G heated above its annealing point can be performed by a rotatable forming member (62) having curved projections (66) or by a press member (78) having elongated projections (84). The constructed plasma display panel (20) has a front glass substrate (22) and a back glass substrate (24) with the gas discharge trough and barrier rib construction made by hot forming above the annealing point.