Litef Gmbh

Northrop Grumman Litef Gmbh

Sven Voigt

Guenter Spahlinger

Alfons Newzella

Christian Koos

Gunter Spahlinger

Wolfgang Freude

Juerg Leuthold

Günter Spahlinger

Steffen Zimmermann

Georg Dorner

The invention relates to an integrated optical coupler () comprising a substrate (), at least two planar waveguides (), which are arranged on or in the substrate () and consist of a material having a virtually isotropic refractive index (anisotropy of the refractive index of less than 10), and al least three monomode fibers () coupled to the planar waveguides (). One of the monomode fibers () is a polarization-maintaining fiber. A fiber optic system according to the invention comprises an integrated optical coupler () according to the invention, a light source () that is suitable for generating light beams, and a first pigtail fiber (), which is connected at one end to the light source () and at the other end to the polarization-maintaining fiber () of the integrated optical coupler ().

Integrated optical coupler and fibre-optic system having such an integrated optical coupler

In an integrated optical circuit, light from a light source is polarized and coupled to a first and second strip waveguide. A waveguide coupling element couples the two optical signals from the two strip waveguides to different polarization modes of an optical fiber line. The optical fiber line is connected to a measuring head, which reflects the optical signal and in which a phase difference between the two optical partial signals is modulated in a magnetic field. In the waveguide coupling element, the reflected signal is split into two optical partial signals having the same polarization and the phase difference between the two partial signals is determined. A phase modulator device provides for closed-loop operation. Compared to fiber-optical concepts, the number of splices is reduced.

Integrated optical circuit and method for measuring current as well as sensor module and measuring device

A digital integrated optical modulator, in particular for a fiber optical signal transmission or measuring device, having two waveguide arms and electrodes that are arranged along both waveguide arms in or on an optical substrate, wherein the arrangements of the electrodes along the two waveguide arms are different from each other.

Electrooptical digital waveguide modulator

An optical transceiver comprises a substrate having a temperature control device, a light source, a light-guiding fiber, a detector, optics for collimating the light from the light source, coupling optics for focusing the light beam into the light-guiding fiber, and a beamsplitter which sends one part of the collimated light beam into a wavelength stabilization unit and another part of the collimated light beam into the coupling optics. A wavelength stabilization unit detects and compensates for wavelength drift of the light source. The optical transceiver has a superluminescent diode for its light source and may, for example, be integrated in a fiber-optic gyro.

Optical transceiver and method of operation thereof

A digital phase modulator for a fiber-optic measurement device. A predetermined total number of electrodes of different lengths are arranged in parallel and on both sides of a light guidance path in or on an optical substrate. The electrodes are arranged in two or more triples along the light guidance path. In each case, two electrodes of successive length within a triple have the same length ratio with respect to one another. Such length ratio is chosen, in particular, to be &#x3bd;=1.618. The electrode lengths of this triple are chosen such that the smallest step widths of the output value range of the phase modulator can be formed by subtraction between the values of at least two larger electrodes. This allows the resolution of the phase modulator to be increased from 9 bits to 11 bits without change in chip size.

High-resolution digital phase modulator for a fiber-optic signal transmission or measurement device

A method and arrangement of electrodes for increasing the resolution of a digital phase modulator for a fiber-optic signal transmission or measuring device. A predetermined total number m of electrodes of different lengths are arranged parallel and on both sides with respect to a light guiding path in or on an optical substrate. The electrodes are divided into two groups. A first group n of electrodes represents a coarse modulator with binary and more significant weighted electrodes of length ratio b:b=2, the longest electrode of which corresponds to the sum of lengths of all the remaining electrodes of the overall modulator. A second, smaller group of nnon-binary and less significant weighted electrodes represents a fine modulator. The smallest output values are not formed by driving individual electrodes of the fine modulator, but rather by forming the difference, in each case, between two larger electrodes.

Digital phase modulator for a fiber-optic device

A method for regulating the operating frequency of a closed loop fiber optic gyroscope. The demodulated output signal of a detector, as actual signal, is applied to the input of a main controller and, via a gating filter, to a VCO that determines the system clock of the FOG. An additional modulation signal, as analog signal is fed to separate phase correction electrodes that are formed together with the electrodes of a digital phase modulator in an integrated optical chip.

Method for regulating the operating frequency and multifunctional integrated circuit chip for a fiber-optic gyroscope

A highly stable broadband light source includes a semiconductor light source having a specific emission spectrum, an optical filter having a specific bandpass filtering function and a predetermined bandwidth and a coupling element, to which the light emissions of the semiconductor light source and of the optical filter are fed. The light emission of the broadband light source occurs at the output of the coupling element. The spectrum of the light emission of the broadband light source is composed of the emission spectrum of the semiconductor light source and the bandpass filtering function of the optical filter. The wavelength of the optical filter is temperature-stabilized so that the spectrum of light emission of the broadband light source is essentially determined solely by the filtering function of the optical filter.

Highly stable broadband light source and suitable stabilization method therefor

A device for current measurement based on a fiber-optic in-line Sagnac interferometer includes a birefringence phase modulator for non-reciprocal phase modulation of two orthogonal polarization modes of a light beam passing through the interferometer. The phase modulator is a digital phase modulator that is directly digitally drivable to permit simplification of the corresponding signal processing or driving electronics unit.

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Freiburg, Germany

Sven Voigt