Abstract: A polarization scrambler, and associated method for polarization scrambling, is provided wherein light is passed through a time-variant retarder. At least after upstream connection or downstream connection of a time-invariant retarder, this time-variant retarder may be represented as a retarder with eigen modes which are uniformly distributed on the Poincaré sphere and with a delay of 5&pgr;/6. An exemplary embodiment contains only two electro-optical wave plates, which are actuated by alternating signals containing harmonics. The polarization scrambler which is produced is independent of the input polarization of the light and can be used in devices for detection of polarization mode dispersion.

Abstract: Resonator which can be produced by micromachining and has a mass part (DF1, DF2, V1, V2) which is fixed by means of a resilient suspension (FA) to an anchoring point (AN) in such a way that it can perform rotary oscillations in its plane, in which, in the rest position of the mass part, the resilient suspension is aligned only along an axis (SAX) of symmetry with regard to which the mass part is of mirror-symmetrical design.

Abstract: An optical signal alternately traverses a total of n couplers and n−1 DGD units, arranged therebetween, with a differential group delay between two signal modes. The power division between the two signal modes is measured in each DGD unit in a power division controller, and a signal that is proportional to the difference between the powers in the two signal modes is obtained. The signal is led to an integrating controller whose control signal is led to a differential phase shifter that is accommodated in the DGD unit present upstream in the beam path. The difference between the powers of the two signal modes is thereby brought to zero at least approximately. This has the consequence that it is essentially only the chromatic dispersion that is generated or equalized, but no other disturbing distortions of the optical signal are produced.

Abstract: An emulator or compensator (EK) of polarization mode dispersion of a polarization-maintaining light waveguide (PMF) with a differential group delay time (DGD), a polarization transformer (PT) and an output (AA). The polarization transformer (PT) is likewise implemented in polarization-maintaining light waveguide and allows endless polarization transformations. The emulator or compensator (EK) can be composed of a plurality of individual emulators or compensators (1, 2, . . . N) that respectively comprise an input (E) and an output (A).

Abstract: The invention specifies a method and apparatus for optical polarization control which enable non-ideal component behavior to be corrected by means of a calibration table. This ensures shorter constructional length, lower operating voltages or higher level functions (ER instead of GSBA).

Abstract: For characterizing polarization transformers or PMD compensators, a polarization transformer to be characterized is operated as a mode converter with full mode conversion and variable orientation. A polarization control sees to it that a further polarization transformer assures the desired, overall polarization transformation. Conclusions about the precision with which the polarization transformer to be characterized works can be drawn from the nature and strength or, too, from the absence of changes of control signals of this further polarization transformer, and this can be improved. The method is particularly suited for the automatic follow-up of DC drift in polarization transformers or PMD compensators with lithium niobate components.

Abstract: Rotation rate sensor as a micromechanical component in silicon, in which a ring with a rigid strut along a diameter is so suspended at elastic braces and anchoring arrangements on a substrate as to be able to perform rotation oscillations about its center axis and to be able to be tilted about the strut under the influence of outer torques. There are electrodes present at the ring and at the substrate, at which electrodes electrical voltages can be applied such that rotary oscillations of the ring about its center axis can be excited and rotary oscillations about the strut can be detected. To stabilize the position of the ring in the neutral position, additional electrodes can be provided at the ring and at the substrate for the generation of electrostatic forces.

Abstract: A capacitance to be measured is connected together with three further capacitances to form a bridge circuit, in which each two of the capacitors are connected in series, and these two series circuits are connected in parallel to one another, and which replaces a part of the input stage of a .SIGMA.-.DELTA. modulator. As inputs of this bridge circuit, terminals are provided at the ends of these series circuits, and as outputs terminals are respectively provided between the capacitors connected one after the other in series. In a sensor realized thereby, two capacitively measuring sensor elements of the same type are used. These capacitors are built into the bridge circuit together with two equally large reference capacitors in such a way that exactly one measurement capacitor and one reference capacitor is La connected is connected to each input and to each output of the bridge circuit.

Abstract: Apparatus and methods are disclosed for readjusting a modulation shift of a transmission light modulated optical signal. In these systems and methods, a first modulated portion of the modulated transmission light is removed to obtain a first modulated signal which is divided into first and second light beams. The first light beam is delayed by a specific delay time and the first and second light beams are coherently superimposed to obtain an optical superposition signal which is detected to produce a detector signal that is proportional to a power of the superposition signal. An error signal is subsequently generated from the detector signal which is representative of a modulation shift from a desired shift value which is used for substantially correcting a modulation of the transmission light.

Abstract: Novel structure and methods for tuning the local oscillator of an optical superheterodyne receiver are disclosed. In a first method, the value of the local oscillator frequency at which the maximum of the chronological average of the output signal from the demodulator occurs is used to set the local oscillator frequency. An alternate method first and second discriminators are used to receive the intermediate frequency signal. The separate discriminator characteristics of the first and second frequency discriminators are used in setting the local oscillator frequency.

Abstract: A stabilization of the frequency spacing between the carrier frequency channels of the individual transmitters and the elimination of the risk of the channel crosstalk is obtained for an arbitrarily large number of transmitters in a coherent optical multi-channel arrangement which has a plurality of transmitters arranged in a group, a single coherent optical heterodyne arrangement for heterodyning a portion of the output of each of the transmitters with respective reference frequency lines and a control arrangement for controlling the channel carrier frequency of each of the transmitters by utilizing the heterodyne signal.

Abstract: Method and apparatus for generating a distortion-free, frequency-modulated optical signal, whereby this signal from an optical semiconductor laser driven with a modulating voltage is distorted by the modulating voltage due to a thermally conditioned frequency transfer function of the transmitter for the modulation frequency of the modulating voltage. For generating the distortion-free, frequency-modulated optical signal, the modulating voltage and/or the distorted, frequency-modulated optical signal itself and/or a superimposition signal containing this optical signal is subjected to a distortion that entirely or partially compensates the distortion of this optical signal. This method is simple and, in combination with receivers for the frequency-modulated optical signal, avoids sensitivity losses.