Abstract: A join process is disclosed for a wireless mesh topology network. In the network, nodes have multiple spatial coverage sub-sectors together covering a larger sector angle and a node can establish connection with other nodes located in directions covered by its sub-sectors. The join process adds a joining node to the network and includes having the joining node listen to sub-sectors at a specific receiving frequency for a defined time. Thereafter, the network node changes its sub sectors and its receiving frequencies according to a defined timing and sequence. Active network nodes transmit organized invitation data packets on defined sectors, frequencies and timing, based on relative location and relative angle orientation deduced from sub-sectors already in use for existing internal network communication. This reduces frequency interference in the network and reduces time required for the join process.

Abstract: An optical modulation system having cascade-coupled electro-optic modulator stages in either dual tandem or split tandem configurations. An electrical splitter derives multiple electrical drives for the multiple stages from a single modulating input signal. The multiple drive signals are linearly related in magnitude and preferably induce simultaneous antiphase (180.degree. out-of-phase) optical modulation in the tandem stages. While a double Mach-Zehnder cascade configuration could be used, at least one modulator stage might instead be a balanced-bridge interfometer-type modulator having at least one directional coupler. At least one directional coupler in such a configuration may be a .DELTA..beta. coupler. Application of bias voltages to the interferometer sections and to coupler sections by means of a parametric feedback loop is done in order to simultaneously enhance the linear modulation coefficient, minimize odd order distortions and null the even order distortions that are associated with biased .

Abstract: A laser generates a beam which is actively steered into an optical element having a waveguide which receives and transmits the beam. The waveguide is coupled to an optical fiber which is also actively steered. Both the beam steering and fiber steering mechanisms seek to align the beam from the laser to the fiber for maximum output. The beam steering mechanism features a pair of planar mirrors pivoted at right angles to each other. A precision force transducer will cause desired amounts of pivoting to adjust the beam. The fiber steering mechanism features a pair of flexures, arranged with bending moments of the flexures being at right angles. Electrical signals control the extent of bending in each flexure. The amount of light in the fiber is sensed downstream from both steering mechanisms and compared to an expected amount.

Abstract: The invention discloses a general technique of taking advantage of the stability of the modulator transfer characteristic in order to correct for second and third order distortion. These objectives are achieved in a way compatible with the nature of the video distribution frequency formats. The method of this invention for linearizing the amplitude transfer characteristic of integrated optic devices for analog transmission is accomplished by injecting pilot signals, monitoring the harmonic and intermodulation distortion content of the optical output, and feeding back bias signals to parametrically tune the operating points of the integrated optic modulator and of a predistortion network. General principles for realizing suitable parametrically tunable predistortion networks are also presented.

Abstract: Apparatus and method for determining dynamically the polarization vector direction, or polarization vector components and associated temporal phase angle, of a light beam. The apparatus includes a compact polarization beam splitter that receives a beam of light, separates the beam into two perpendicular polarization components and directs these components to a pair of optical detectors and associated circuits that form the sum and difference signals of the electrical signals produced by the optical detectors. This produces a projection of the polarization vector on a given direction. If the light is generally elliptically polarized, use of two such polarization beam splitters and four optical detectors allows reconstruction of the polarization ellipse for the light beam. Alternatively, use of one such polarization beam splitter, two optical detectors and a rotating wave plate in a multiplexed configuration allows reconstruction of the polarization ellipse.