Abstract: For reducing power fluctuations of spectral lines of a comb generator having an annularly closed waveguide, a coupler for coupling light from a separate light source into the waveguide and out of the waveguide and also a sideband modulator, the light circulating in the waveguide can be either separately modulated or the sideband modulator can be operated to have only sidebands of the same operational sign of a frequency shift or with an amount being selected according to a particular arrangement, or can have both positive and negative frequency shifts with the amount being selected by a different formula or the length of the annularly closed waveguide can be dimensioned so that the size of the round-trip time of the light circulating in the waveguide is longer than the defined coherent time of the reference laser light. It is also possible to incorporate various combinations of these alternative ways of reducing the power fluctation.

Abstract: Method and apparatus for obtaining phase and/or polarization-insensitive optical heterodyne receiving for DPSK or ASK-modulated transmission signal wherein an intermediate frequency which is very low as compared to the data rate of the signals is utilized and at every clock of the transmission signal the phase of the signal is shift keyed between 0.degree. and 90.degree. at the start A1 and in the middle M of the clock time T and the polarization of the signal is shift keyed at least at the start A2 of the second and at the start A4 of the fourth quarter of the clock time T. The transmission signal which is shift keyed in this manner is received by a simple optical heterodyne receiver which has the special characteristics that an intermediate frequency filter ZFF is an integrator which integrates over a respectively one-quarter of the clock time T.

Abstract: An external optical resonator for a semiconductor laser is composed of an optical directional coupler which can be formed as an integrated optical coupler with a short structural length that enables a free spectral range in the order of 100 GHz and enables the resonator and the system fiber to be coupled to the same end face of the laser. The resonator structure includes two optical waveguides with feedback means applied on the end faces of one of the waveguides and the other waveguide having one end face coupled to receive the output of the laser and the other end face of the other waveguide being coupled to the system fiber. The arrangement is particularly useful for tunable semiconductor lasers, particularly for heterodyne reception.

Abstract: An apparatus for generating an FSK-modulated optical signal has an optical two-filter FSK super-heterodyne receiver. The optical signal has two different polarization conditions that are orthogonal to one another. Due to the two-filter receiver and orthogonal conditions, polarization-independent reception is possible. Conversion of the polarized, optical signal into the optical signal having the orthogonal polarization conditions is accomplished by a switching device. Each condition has a corresponding bit status of a data signal. The data signal effectively controls the polarizatiion of the optical signal. Hence, the frequency boost can be freely selected while maintaining excellent bandwidth characteristics and optimum sensitivity.

Abstract: A method for generating an FSK-modulated optical signal with an optical two-filter FSK super-heterodyne receiver. The optical signal has two different polarization conditions that are orthogonal to one another. Due to orthogonal conditions, polarization-independent reception is possible. Synchronized polarization shifting occurs to generate a polarized modulated optical signal having alternating orthogonal polarization conditions. A delay stage for delaying the switching signal by one-half a clock period ensures accurate synchronization. The frequency shift of the FSK-modulated signal can be freely selected while maintaining excellent bandwidth characteristics and optimum sensitivity.

Abstract: A narrowband laser transmitter which has a semiconductor laser and an external optical resonator coupled to the semiconductor laser so that the output power of the transmitter can be taken from the resonator, characterized by the laser transmitter being both a micro-optical realization or implementation as well as executed with a free beam propagation. To this end, the resonator is composed of an optical grating arrangement arranged in the beam path of the laser emission from the semiconductor laser and this optical grating arrangement will conduct one part of the supplied laser emission back to the semiconductor laser while conducting the other or second part of the emission to a coupling location at which the other part can be taken as the output power of the transmitter.

Abstract: An arrangement has at least one, and preferably two, optical waveguides integrated on a substrate of electro-optical material, has at least one first electrode for each of the waveguides being applied on the substrate and separated from the waveguide and substrate by an insulating layer and has at least one second electrode for each of the waveguides. The second electrodes are connected to a constant voltage source, while the first electrodes are connected to a modulating voltage source. The constant voltage source applied to the secondary electrodes and the position of these electrodes relative to the waveguides determines an operating point for modulating light in the waveguides.

Abstract: A laser transmitter comprising a semiconductor laser, and an external resonator in the form of an optical directional coupler characterized by feedback device being allocated to a first waveguide of the directional coupler and also a second feedback device allocated to the second waveguide of the coupler, each of the feedback devices returning a portion of the radiant energy in their respective waveguides back along the waveguide to the directional coupler and the output power of the transmitter being taken from the second waveguide of the directional coupler. Preferably, the section of each of the waveguides between the directional coupler and the respective feedback means has a different length with the difference being substantially in the magnitude of the length of the semiconductor laser. Preferably, the waveguides are strip waveguides integrally formed on a substrate and can include a modulator, as well as having the semiconductor laser also integrated on the substrate.

Abstract: A narrow-band laser transmitter including a semiconductor laser and an external optical resonator in the form of a wavelength-selective fiber directional coupler. A partially reflecting feedback device is provided so that output power of the transmitter can be taken from the resonator. The frequency selective fiber directional coupler is formed by a dispersive double core fiber and the feedback device is supplied with radiant laser energy that is coupled over from one core into the other core and that portion of the radiant energy which has been coupled over is allowed to pass as output power of the transmitter by the feedback device.

Abstract: A light deflector includes a plurality of individual acousto-optical light waveguide deflectors being integrated on a common substrate and disposed relative to one or more directions from which or to which a light beam to be deflected will be supplied so that the resolved points is equal to the sum of the resolved points of each of the individual deflectors. Preferably, the individual light deflectors are disposed and aligned on the substrate so that the deflection ranges of the resolved points lie next to one another in a prescribed surface and with the ranges contacting one another without gaps.

Abstract: A narrow band laser transmitter comprising a semiconductor laser and an external optical resonator coupled by a coupling arrangement to the semiconductor laser characterized by the external optical resonator being a wavelength-selective fiber directional coupler in the form of a double core fiber whose cores have different refractive index discontinuities to the respective environments and different cross-sections. The laser transmitter is suitable for practical use, has a space-saving structure and is stable in operation.

Abstract: A method and apparatus for positioning a laser diode with respect to a coupling optic for a waveguide to obtain the optimum light transmission characterized by providing a reflecting reference plane or surface extending perpendicular to the axis of the waveguide adjacent the coupling optic, projecting light through the waveguide and coupling optic onto the reflecting surface, measuring the amount of light reflected into the waveguide and adjusting the axial position of the waveguide and optic relative to the reflecting surface to obtain the optimum value, then placing the semiconductor with the facet in the reference plane and either operating the semiconductor to provide light for coupling into the waveguide and adjusting the relative positions in a transverse plane to the axis of the waveguide to obtain the optimum transmission or operating the semiconductor laser as a detector and coupling light into the waveguide at a point spaced from the laser to project into the detector and making adjustments in the t

Abstract: A controllable integrated optical component comprises a substrate having electro-optical properties into which optical waveguides are introduced and given which metallizations in the form of a plurality of electrodes which are chargeable with electrical voltages are applied on or next to the optical waveguide. This, a coplanar microwave line is exposed next to the optical waveguides, whereby respectively one electrode is electrically connected to respectively one strip of the microwave line and should also enable a reproducible microwave mode even for microwave frequencies that are as high as possible. The electrodes are disposed between the strips of the microwave line. When the connecting lines between the electrodes and the strips of the microwave line are strip lines, the integrated optical component can be manufactured in planar technology. Fabrication is thereby significantly simplified.

Abstract: A controllable directional coupler comprises two optical waveguides on the surface of a substrate of electrooptical material, the waveguides extending parallel for a predetermined distance. The coupler also comprises a control electrode structure including a pair of control electrodes formed on the surface of the substrate and covering the two parallel waveguides along their lengths. In order to achieve low control voltage and a low coupling loss, in the case of butt coupling to a monomode fiber, in the interstice between the two optical waveguides, the refractive index of the substrate is reduced to a specific depth of the substrate at which the coupling intensity becomes largely independent of the near-field expansion in the waveguides.

Abstract: An arrangement for producing a broadband junction between a microstrip line and a coplanar transmission line in the following called "twin band line" provides that the microstrip line and the twin band line (ZL) extend at right angles relative to one another. The ground electrode of the microstrip line and the ground electrode of the twin band line lie immediately one on top of the other. The strip-shaped other electrodes of the microstrip line and the narrower strip-shaped electrode of the asymmetrical twin band line which extends at right angles thereto and coplanar to the wider ground electrode of the twin band line are connected to one another in a broadband manner by one or more ribbons or wires of metal. The arrangement is advantageously employable as a fast integrated optical modulator with cutoff frequencies in the GHz range, whereby the spacing between the coplanar electrodes expediently constricts conically in the longitudinal direction thereof.

Abstract: A frequency analyzer, which is manufactured in a planar waveguide technology has a first substrate provided with a waveguide modulator for modulating light travelling in the waveguide connected to a lens for the Fourier transformation of the modulated light. The material of the lens is different than the material of the substrate having the modulator and preferably is either a rod shaped gradient lens or a second substrate, which as a geodesic waveguide lens pressed into the surface.

Abstract: A prism coupler for coupling light into and out of an optical waveguide and characterized by the temperature dependency being eliminated. This is accomplished by a skillful selection of the prism angle and the prism material of a single prism or by combining two prisms of different materials whose indices of refraction and prism angles are selected to compensate for the effects of temperature on both the prism and the waveguide. Preferably, the waveguide is doped in a substrate of LiNbO.sub.3 and the prism utilizes a compound prism having a first prism consisting of LiNbO.sub.3 and a second prism of polystyrene.

Abstract: An optical device, such as the switch, for controlling the passage of a light beam into and out of an end face of a waveguide such as a glass fiber includes utilizing either a layer or drop of liquid material to control the light passage. The liquid material can be a layer, which has changeable optical properties, which can occur by applying a magnetic field, heat or electrical field or the material can be a layer of electrolyte material which will precipitate a reflective layer or electrochromic layer in response to an application of an electrical field. In another embodiment, the liquid material may be moved into and out of engagement with the end face to change the reflective nature of the end face and to cause decoupling of light from the end face or block the transmission of light.

Abstract: The planar waveguide Bragg lens and a component utilizing a planar waveguide Bragg lens with a greater acceptance angle characterized by several grating structures being arranged in series and having an inclination towards one another for varying angles of incidence. In one embodiment, each of the grating structures are circular arc segments which are interconnected together to form a single grating structure having curved segments which also has a greater acceptance angle than a conventional planar waveguide Bragg lens.

Abstract: A planar electro-optical light deflector is operable to provide a plurality of beam positions and is characterized in that the same is a Bragg deflector having several adjacently-disposed electrode structures which are separately activatable, have respective different grid constants and are disposed on a layer waveguide inclined in such a manner that the light impinges on the respective electrode structures under respective Bragg angles, whereby the layer waveguide is capable of excitation over a width which corresponds to the totality of all electrode structures.