Abstract: A positioning system, including: a first plate; a second plate coupled to the first plate and pivotable about an axis; a pair of voice coil actuators configured to rotate the second plate about this axis; and a processor configured to drive currents to the pair of voice coil actuators; wherein the pair of voice coil actuators comprises a first and second magnet structures mounted on the first plate at equal and opposite distance from the axis, and a first and second coils mounted on the second plate and positioned such that the respective first and second magnet structures move in and out of the first and second coils when the second plate rotates about the axis; wherein each of the first and second magnet structures substantially conforms to an arc having a center at the axis and a radius equal to the distance of the magnet structure from the axis.

Abstract: A fast steering optical mirror for laser beam deflection, moved by at least one rotational axis, including: a plate containing a plurality of carbon fiber layers laid up in a resin, wherein the plate includes a front face, at least a portion of the front face being polished and coated for laser light reflection; and wherein a surface normal of the front face is aligned orthogonal to the at least one rotational axis. A method of manufacturing fast steering optical mirror including: forming a plate having a front face and a back face by laying up a plurality of carbon fiber layers in a resin; aligning the plate so that a surface normal of the plate is orthogonal to at least one rotational axis of the mirror; and polishing and coating at least a portion of the front face for light reflection.

Abstract: A positioning system, including: a first plate; a second plate coupled to the first plate and pivotable about an axis; a pair of voice coil actuators configured to rotate the second plate about this axis; and a processor configured to drive currents to the pair of voice coil actuators; wherein the pair of voice coil actuators comprises a first and second magnet structures mounted on the first plate at equal and opposite distance from the axis, and a first and second coils mounted on the second plate and positioned such that the respective first and second magnet structures move in and out of the first and second coils when the second plate rotates about the axis; wherein each of the first and second magnet structures substantially conforms to an arc having a center at the axis and a radius equal to the distance of the magnet structure from the axis.

Abstract: A Shack Hartmann (“SH”) wavefront sensor comprising an optical device, such as a wave front dissector including a lenslet array, for transmitting, dissecting and focusing an incoming optical wave, an optical system, including, for example, an optical sensor, for receiving the transmitted incoming optical wave, and a removable kinematic mount for repeatable precision mounting of the optical device to the optical system.

Abstract: A Shack Hartmann (“SH”) wavefront sensor comprising an optical device, such as a wave front dissector including a lenslet array, for transmitting, dissecting and focusing an incoming optical wave, an optical system, including, for example, an optical sensor, for receiving the transmitted incoming optical wave, and a removable kinematic mount for repeatable precision mounting of the optical device to the optical system.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: It is possible to improve the manner in which the chromatic dispersion of a sample (4) is determined. To this end, the sample (4) is irradiated in an interferometer (10), with the light of a radiation source (1). A downstream polarimeter (50) measures both the power changes and the polarization changes of the interference radiation. In the downstream evaluation unit (7) the wavelength-dependent chromatic dispersion can be determined.

Abstract: What is described here is a system for compensating distortions induced by polarisation modulation dispersion (PMD) in optical transmission systems and in transmission fibres in particular, comprising a means for measuring PMD-induced distortions, an emulator unit for adjustable PMD levels, and a controller which the output signal of said measuring means is applied to and which serves to control said emulator unit. In accordance with the invention both the emulator unit and the measuring means are improved for the PMD-induced distortions as well as the controller and the applied control criterion (alone or in combination).

Abstract: A PMD emulation, measurement and compensation device is based upon an emulation device having a piece of fiber having a fixed differential group delay (DGD) and another short piece of fiber (or double refracting crystal) having a variable differential group delay (T-DGD). The two pieces of fiber are coupled with a non-zero torsional angle between their respective double refractive axes, preferably 45°. A fiber squeezer/stretcher is used to provide the variable DGD for the short piece of fiber. Various serial couplings of DGD and T-DGD fiber may be added to provide greater control and accuracy, with the torsional angles preferably alternating. Such an emulation device may be incorporated into a measurement device to measure the PMD-related distortion of an optical signal. Further the measurement device may be used in a PMD compensator where an emulation device in series with the optical signal path is controlled until the measured PMD in the PMD-related distorted optical signal is minimized.

Abstract: Highly accurate calibration of a polarimeter of the type having at least four detectors involves using four known states of polarisation of an input light signal (calibration polarisations) and at least one further state of polarisation. All input states of polarisation to the polarimeter have unity normalised power of the light signal and unity degree of polarisation. A Stokes matrix for the four calibration polarisations is generated with at least one variable correction parameter, and a correction matrix is determined from the Stokes matrix and a corresponding detector current matrix measured by the polarimeter. An optimisation criterion that is a function of the degrees of polarisation for the states of polarisation as measured by the polarimeter is generated. The correction parameter is varied iteratively to minimise the optimisation criterion so that the polarimeter is calibrated to produce unity power and degree of polarisation for any input state of polarisation.

Abstract: The invention relates to a device for detecting the PMD of optoelectronic transmission lines. The inventive device is characterized in that it comprises a narrow-band, tunable laser, whose illumination is superimposed with the illumination of the transmission line to be analyzed and an optoelectronic heterodyne receiver which receives the superimposed signal.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: It is to be possible for the chromatic dispersion of a sample (4) to be determinable in an improved manner. To this end the sample (4) is radiographed, in an interferometer (10), with the light of a radiation source (1). A downstream polarimeter (50) measures both the power changes and the polarisation changes of the interference radiation. In the downstream evaluation unit (7) the wavelength-dependent chromatic dispersion can be determined.

Abstract: A PMD emulation, measurement and compensation device is based upon an emulation device having a piece of fiber having a fixed differential group delay (DGD) and another short piece of fiber (or double refracting crystal) having a variable differential group delay (T-DGD). The two pieces of fiber are coupled with a non-zero torsional angle between their respective double refractive axes, preferably 450. A fiber squeezer/stretcher is used to provide the variable DGD for the short piece of fiber. Various serial couplings of DGD and T-DGD fiber may be added to provide greater control and accuracy, with the torsional angles preferably alternating. Such an emulation device may be incorporated into a measurement device to measure the PMD-related distortion of an optical signal. Further the measurement device may be used in a PMD compensator where an emulation device in series with the optical signal path is controlled until the measured PMD in the PMD-related distorted optical signal is minimized.

Abstract: Highly accurate calibration of a polarimeter of the type having at least four detectors involves using four known states of polarisation of an input light signal (calibration polarisations) and at least one further state of polarisation. All input states of polarisation to the polarimeter have unity normalised power of the light signal and unity degree of polarisation. A Stokes matrix for the four calibration polarisations is generated with at least one variable correction parameter, and a correction matrix is determined from the Stokes matrix and a corresponding detector current matrix measured by the polarimeter. An optimisation criterion that is a function of the degrees of polarisation for the states of polarisation as measured by the polarimeter is generated. The correction parameter is varied iteratively to minimise the optimisation criterion so that the polarimeter is calibrated to produce unity power and degree of polarisation for any input state of polarisation.

Abstract: The invention relates to a device for detecting the PMD of optoelectronic transmission lines. The inventive device is characterized in that it comprises a narrow-band, tuneable laser, whose illumination is superimposed with the illumination of the transmission line to be analysed and an optoelectronic heterodyne receiver which receives the superimposed signal.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.