Abstract: A method is described for the exact calculation of the field distributions and the phase constants of single and coupled dielectric image lines of rectangular cross section. Field distributions and phase constants calculated by this method are presented as well as experimental results from lines fabricated of paraffin wax. The physical properties of the electromagnetic fields and the mode designation are discussed. The theory is compared to approximate calculation methods known from the literature.

Abstract: A beam of light is split and introduced into different ends of a light path whose rotation is to be sensed. At least one frequency shifter is placed in the light path to affect the frequency difference of the two beams so as to introduce or adjust a nonreciprocal phase shift. The beams are then mixed back together and the resultant beam is detected and analyzed by suitable circuitry to provide an output indicative of rotation of the light path.

Abstract: The velocity measuring correlation sonar disclosed employs a planar array of receiving transducers spaced in the directions along which velocity components parallel to the plane of the array are to be measured, and includes means for transmitting a series of two or more identical pulses which are separated by a time interval selected in accordance with transducer separation and the estimated velocity components so as to place the expected point of maximum correlation of the echo return from one pulse with that from a following pulse within the boundaries of a set of spatial sample points representing relative spacings between pairs of receiving transducers. Correlation measurements are made corresponding to these relative spacings of the receiving transducers, with each such measurement being treated as a sample of a space-time correlation function of predetermined shape. The location of the peak of this function in each of the directions of interest is estimated by curve fitting techniques, and yields the velocity vector in that direction scaled by the inter-pulse time interval. The velocity component normal to the plane of the array may be derived by estimating the location of the correlation peak as a function of time and/or phase, using similar curve fitting techniques.

Abstract: Two methods are presented for sensitive measurement of nonreciprocal phase shift (NRPS) in a multi -turn fiber Sagnac interferometer for application in inertial rotation sensing. Both techniques are capableof producing an NRPS modulation of amplitude ± r radians at a rate sufficiently high for shot -noise - limitedperformance. The first method produces an NRPS by generating a nonreciprocal refractive index using theelectro -optic effect, and requires orthogonal polarization in the cw and ccw beams. The second method produces an NRPS by generating a nonreciprocal propagation frequency using two acousto -optic shifters;there is no requirement on light polarization. When either method is used in conjunction with phase- sensi-tive detection, feedback compensation, and adequate laser intensity, shot -noise -limited measurement be- comes possible. Preliminary performance data is included. Introduction Currently there is considerable interest in using a multiturn fiber Sagnac interferometer for the mea-surement of inertial rotation.l Such a measurement is difficult to perform because the nonreciprocal phaseshift (NRPS) induced in the fiber by inertial rotation is very small. For a rotation rate SZ, the NRPS 04) is

Abstract: Some experimental results on the operation of a lithium niobate modulator in a threshold circuit to simulate a bit channel of an analog‐to‐digital (A/D) converter are presented. Voltages required for π‐radian phase retardation were 1.2 and 3.1 V, respectively, for TE and TM excitation. The periodic dependence of modulator intensity on applied voltage is maintained for phase shifts as large as 24π radians in the TE case, which corresponds to 5.6 bits of precision for an A/D converter.

Abstract: The invention relates to phase locked loops in which a variable-frequency voltage-controlled oscillator (VCO) feeds a phase comparator via an adjustable divider having a division factor N. The comparator compares the phases of the divided frequency (Fd) and a reference frequency (Fr), and adjusts the VCO to produce phase equality. To enable the VCO frequency (FO) to be adjusted in smaller steps than Fr and yet maintain a loop bandwidth greater than the step size with good spurious performance (thus providing a "fractional N synthesizer"), Fo is made slightly more than N.Fr. The phase detector thus produces a phase error signal. At periodic instants, determined by the period of the frequency difference between Fo and N.Fr, a control unit temporarily increases N by unity so as to bring Fd and Fr into phase. To eliminate the sawtooth waveform that would otherwise be produced on the phase error signal, the control unit also produces unit increases in N during each such period so as to produce a phase difference between Fd and Fr which is opposite in sign to, and substantially offsets, the integrated value of the phase differences up to that instant. The phase error signal therefore undergoes only residual variations, and these are backed off by an analogue output derived from the control unit.

Abstract: Time‐dependent fluorescence processes can be investigated using a phase fluorometer with variable frequency. The high cutoff frequency of 500 MHz leads to a time‐resolving power of about 1 ps.

Abstract: This report is one individual’s attempt to organize and integrate a rather unstructured set of remarks made on a controversial subject during this session. This session first dealt with questions regarding the location “in GI” at which various

Abstract: A control system for a multi-phase synchronous machine having a shaft driven at variable speed or for developing a variable torque angle includes shaft angular position detectors that derive first and second output pulses respectively representing a shaft angular displacement corresponding with each pole of the machine and a predetermined shaft angular displacement within each pole. In response to a plurality of the second output pulses, a frequency locked loop derives a variable frequency pulse output. Individual pulses are selectively inserted and deleted from the variable frequency output to derive a variable phase pulse output representing machine torque angle. A triangle up/down counter responds to the variable phase output to derive a pulse output signal having a frequency that is a submultiple of the variable frequency output and a phase determined by the phase of the variable phase output. The time position of pulses of the first output and the up/down counter are compared to control the insertion and deletion of the individual pulses. Each phase of the machine is driven in response to the output signal of the triangle up/down counter.

Abstract: The present invention relates to a phase corrected raster scanned light modulator in which information modulated on a carrier is used to form a grating whose spatial frequency along the scanning line varies in accordance with the signal modulation frequency. Thickness variation in the medium on which the grating is formed causes an undesired phase modulation of the light which may be corrected by altering the carrier frequency. A novel oscillator is described which may be stepped discontinuously in frequency while the waveform and its slope remain continuous, which is of sufficient accuracy and agility to provide a real time region by region phase correction of the raster in the light modulator. The variable frequency oscillator is of high stability and can step from one value to another for intervals as short as one microsecond.

Abstract: 1. Asymmetrical displacement currents were studied in myelinated nerve fibres fromRana esculenta with a voltage clamp technique. 2. For brief pulses symmetrical with respect to a holding potential of −97 mV, the asymmetry current flowing during pulses (on-response) exhibited a rising phase to a peak followed by an approximately exponential decline. After the pulses the rising phase in the off-response could not be resolved; the time constant varied about 2-fold with either size or duration of the pulse. 3. For longer pulses a second slower component could be detected both in on- and off-responses. 4. The rapidly declining on- and off-responses associated with brief pulses carried about the same chargesQon andQoff. Increasing the duration of the pulse reducedQoff. For all pulses testedQoff approached about one fifth ofQmax. The reduction ofQoff was roughly characterised by time constants ranging between 1.5 and 0.5 ms for potentials between −25 and +23 mV. Analysis of individual membrane currents confirmed that the capacity current after depolarizing pulses decreased with pulse length. 5. The effects of membrane potential on asymmetry current were studied by varying the level from which pulses were applied during 46.9 ms prepulses in the range from −97 to −29 mV. The fast and slow components of asymmetry current were affected differently. For potentials more positive than −90 mV the fast on-response was reduced and reversed its sign at a potential 25 mV more negative than the potential estimated from the steady-state charge distribution measured from −97 mV.

Abstract: An electronically scanned phased array antenna system comprises a phase shift controller corresponding to each antenna array element for individually computing a phase shift value which governs the phase of the signal associated with the corresponding antenna element. The computed phase shift values of all the phase shift controllers effect a phased array on the signals of the antenna elements to point the antenna beam in a desired direction. Each of the phase shift controllers is programmed with a predetermined phase shift value increment for computing a sequence of phase shift values at specified intervals of a predetermined time pattern, each new phase shift value being preferably concurrently computed by the phase shift controllers at the specified time intervals. The phased arrays resulting from each of the newly-computed phase shift values of the sequence render the antenna beam to be scanned in a corresponding sequence of desired directions according to the specified intervals, which may be non-uniformly spaced, in the predetermined time patterns. Each predetermined phase shift value increment correspondly programmed into each phase shift controller may be based on a function of the geometric position of the correspondingly associated antenna element in the antenna array.

Abstract: The background in saturation spectroscopy is decreased by balancing the probe beam, in amplitude and phase, against a second probe, using a configuration like a Jamin interferometer. This improves the signal-to-noise ratio. If the phase is adjustable to provide best balance while the laser is tuned, the signal is proportional to the square of the absorption, and the line width is accordingly reduced.

Abstract: A laser which self-corrects for distortions introduced into the laser beam wavefronts by aberrations and time-varying phenomena internal to the laser. The improved laser includes a partially transmissive first reflecting element, an aperture stop, a lasing medium and a nonlinear phase conjugate reflecting device as the second reflecting element. During laser operation, aberrated wavefronts impinging upon the second reflecting element are reflected as the phase conjugate waveform thereof. The aperture stop restricts laser operation to the fundamental mode which allows only corrected, unaberrated waves to pass through the aperture stop and to subsequently exit the laser. Four embodiments are described utilizing stimulated Brillouin scattering (SBS), four-wave mixing, three-wave mixing and photon echo devices as the second reflecting element.

Abstract: A method and apparatus for radio geophysical surveying includes measuring the relative magnitude and phase of radio frequency signal components reflected from subterranean formations. The apparatus comprises a transmitter selectively connected to a vertical antenna and a loop antenna, and a pair of receivers, one receiver being connected to a vertical antenna and the other connected to a loop antenna. A surface propagated calibration signal is transmitted and is received by each of the receivers. The outputs of the receivers are connected to the input of a difference amplifier, a difference signal is generated, and the magnitude and phase of the difference signal are measured and recorded. A survey signal, including surface propagated components and earth propagated components, is then transmitted. The survey signal is received, a difference signal is generated, and the magnitude and phase thereof are measured. For each position along the survey path, the calibration magnitude and phase are vectorially subtracted from the corresponding survey magnitude and phase, and the resultant magnitude and phase are plotted. At each position, the data is taken for an electric field vector alignment of the transmitter and receiver loop antennas, and for a magnetic field vector alignment thereof. The transmitter and receivers include means for precisely maintaining consistency throughout the survey.

Abstract: Phase-locked loops have been used in various parts of telecommunication systems because of their wide applicability to bit synchronization and FM- and PM-demodulation, etc. Several types of digital phase-locked loops (DPLL's) have also been studied due to the increased reliability and decreased cost of integrated digital circuitry. DPLL's of the type employing binary quantized phase detection and discrete phase adjustments have been utilized for detection of a binary signal or suppression of phase jitter in data-transmission techniques. Unfortunately the width of the locking-range and the ability to suppress phase jitter are contrary to each other, and furthermore, the capacity for jitter suppression rapidly lowers as the frequency of input signal deviates from a free-running frequency of the loop. To improve these vicious properties, a DPLL employing a new type of sequential loop filter is proposed in this paper. The sequential filter controls the properties of itself asymmetrically, depending on the input and output phase distributions to keep the output phase at the center of input phase distribution. The loop performance is analyzed theoretically, experimentally, and by computer simulation in the presence of random Gaussian phase jitter. It is shown that the loop has satisfactory performance as a DPLL used for phase jitter suppression.

Abstract: A dynamoelectric machine utilizing stiff, multiple component phase leads for connecting potentially misaligned stator coils and parallel phase rings. The phase leads, when attached to stator coil and phase ring coolant headers, provide electrical communication therebetween. The first and second phase lead components have a hole and cylindrical portion respectively wherein the cylindrical portion is insertable in the hole. Such phase lead hole has a longitudinal axis perpendicular to both slot elongation directions. Intimate electrical contact between the phase lead components and their connected coolant headers is insured by disposidng solder between their mateable, plane surfaces. Intimate electrical contact between the phase lead components is insured by brazing the components together at the interface between the assembled cylindrical portion and hole. Translational misalignment between the connectable phase ring and coil is accommodated in the three perpendicular directions by providing the slotted openings and permitting insertion of the cylindrical phase lead portion into the phase lead hole for selected distances. Such selective insertion is obtained by supplying extra stock to the cylindrical phase lead portion and trimming that portion to the appropriate length at assembly time.

Abstract: All harmonics of an order less than (6·N-1) are cancelled from the fundamental signal presented in each output phase of a three-phase converter as the sum of corresponding phase angle fundamental signals from an N number of converter bridges, where N is a non-power of two

Abstract: A radio frequency distance measuring system and method where two continuous wave carrier signals, derived from a stable frequency source, are radiated from a known reference point. The frequency of the first continuous wave carrier signal is displaced from the frequency of the second continuous wave carrier signal by a selected difference frequency. When received at the unknown point, the two continuous wave carrier signals are mixed to provide a difference or beat frequency marker signal, delayed in arrival at the unknown point from the known point by the speed of light. A locally generated marker signal is derived from a stable frequency source at the unknown point, and has the same frequency as the difference frequency signal. The leading or trailing edge of the difference frequency signal can be compared with the locally generated marker signal, and the time difference or phase difference between them can be displayed using a phase meter or time interval indicator and corresponds to determine directly the distance between the known transmitter reference point and the unknown receiver point. Multiple known reference point transmitters, each transmitting two continuous wave carrier signals displaced in frequency by a selected difference frequency, can be used to obtain two or more distance measurements at the unknown point to determine the position of the unknown receive point with respect to the known transmitter points. A chart shows the relationship of the selected difference frequency to the distance that can be measured without ambiguity.

Abstract: The one-dimensional single component Ginzburg-Landau (GL) model where the order parameter couples either linearly to an internal degree of freedom of localized defects or quadratically to rigid defects is studied. It is a model for the influence of defects on the properties of nearly ferromagnetic systems (“giant moment” formation, as proposed by Suhl) and of solids near a displacive phase transition. For isolated defects the nonlinear GL equation can be solved analytically. The exact strength and shape of the localized condensate and the conditions for its existence are calculated and used as a test for previous approximations applicable in three dimensions. Near the local “transition temperature” a localized order parameter mode becomes soft. The temperature dependence of its spectrum and shape and the phase shifts for the scattering of order parameter waves in the regions with and without localized condensate are calculated exactly. The stationary states for a system with two defects are presented. Apart from the stable states, the saddle points across which the system has to pass in going from one stable configuration to another are also discussed. The interactions between the defects induced by the order parameter field, between the localized moments corresponding to the condensate and between the defects and Bloch walls are given.

Abstract: On the basis of the theory of coupled waves the amplitudes of the first-order diffracted waves and the diffraction efficiency is calculated for sequentially superposed phase gratings stored in dielectric reflection holograms. The investigations are restricted to the case of a fixed reference wave during recording and Bragg-angle incidence. By analogy to the transmission volume grating the coupling effects which appear between incident beams and diffracted waves give the possibility of building up beam-couplers and -splitters with certain coupling parameters determined by the recording process. Moreover, reflection gratings allow a favourable combination between coupling and reflecting properties and avoid the diffraction efficiency oscillations that are characteristic of transmission gratings. The performance of the reconstruction process with several waves simultaneously allows the tuning of the intensities of diffracted waves with dependence on amplitude or phase differences between incident beams.