Abstract: The invention relates to a method of generating a feedback signal for adjusting a polarization mode dispersion compensator (PMDC, 21) in a transmission system with alternate-polarization. A first signal (37) is determined by measuring a spectral component of the radio frequency modulation of an optical signal (33) at a particular radio frequency. Preferably, the radio frequency essentially corresponds to half the symbol rate of the optical signal (33). Also a second signal (35) is determined by coupling the optical signal (33) into a delay line interferometer (DLI, 50) having a delay essentially corresponding to the symbol period or an odd multiple of the symbol period between its arms (51, 54). Downstream of the DLI (50), the signal is optical-to-electrically converted. Downstream of the optical-to-electrical conversion, an intensity measurement is performed. The first (37) and second (35) signals are then combined to generate the feedback signal (28).

Abstract: The present invention provides a method and system for transmitting data over an optical channel using OFDM with a variable transmission rate. Such method and system feeds an essentially constant transmission power over a predetermined OFDM bandwidth into the optical channel. In an embodiment, at least two OFDM subcarriers may be modulated with signal information derived from a single word of an OFDM symbol. Further thereto, the frequency spacing between the transmitted OFDM subcarriers may be changed.

Abstract: The invention relates to a method of generating a feedback signal for adjusting a polarization mode dispersion compensator (PMDC, 21) in a transmission system with alternate-polarization. A first signal (37) is determined by measuring a spectral component of the radio frequency modulation of an optical signal (33) at a particular radio frequency. Preferably, the radio frequency essentially corresponds to half the symbol rate of the optical signal (33). Also a second signal (35) is determined by coupling the optical signal (33) into a delay line interferometer (DLI, 50) having a delay essentially corresponding to the symbol period or an odd multiple of the symbol period between its arms (51, 54). Downstream of the DLI (50), the signal is optical-to-electrically converted. Downstream of the optical-to-electrical conversion, an intensity measurement is performed. The first (37) and second (35) signals are then combined to generate the feedback signal (28).

Abstract: The present invention provides an optical waveguide phase shifter that comprises a planar silicon-dioxide-containing optical glass waveguide whose core contains glass, and also a planar optical polymer waveguide whose core contains a polymer and/or a mixture of polymers, furthermore means that effect the change in the temperature of the planar optical polymer waveguide and wherein the refractive index of the planar optical polymer waveguide is greater than the refractive index of the planar silicon-dioxide-containing optical waveguide. The refractive indices of the planar optical polymer waveguide and of the silicon-dioxide-containing optical glass waveguide can consequently be matched even by a small increase in the temperature of the planar optical polymer waveguide. In addition, only the propagation constant of the optical field in a silicon-dioxide-containing optical waveguide according to the invention is influenced by the coupling mode between silicon-dioxide waveguide and polymer waveguide.

Abstract: The production of optical waveguides on waveguide bases which, for example, are formed from a correspondingly structured buffer layer, reduces the birefringence which occurs owing to thermally induced stresses during the glass production process. Therefore, the concentration of dopants (for example boron atoms) in the cladding layer can be reduced to achieve a birefringence-free optical component as complete adaptation of the thermal coefficient of expansion of the glass to that of the silicon substrate is no longer necessary. This has the enormous advantage that optical components, which comprise optical waveguides of this type, remain stable relative to external influences for a long time.

Abstract: The production of optical waveguides on waveguide bases which, for example, are formed from a correspondingly structured buffer layer, reduces the birefringence which occurs owing to thermally induced stresses during the glass production process. Therefore, the concentration of dopants (for example boron atoms) in the cladding layer can be reduced to achieve a birefringence-free optical component as complete adaptation of the thermal coefficient of expansion of the glass to that of the silicon substrate is no longer necessary. This has the enormous advantage that optical components, which comprise optical waveguides of this type, remain stable relative to external influences for a long time.

Abstract: The present invention provides an optical waveguide phase shifter that comprises a planar silicon-dioxide-containing optical glass waveguide whose core contains glass, and also a planar optical polymer waveguide whose core contains a polymer and/or a mixture of polymers, furthermore means that effect the change in the temperature of the planar optical polymer waveguide and wherein the refractive index of the planar optical polymer waveguide is greater than the refractive index of the planar silicon-dioxide-containing optical waveguide. The refractive indices of the planar optical polymer waveguide and of the silicon-dioxide-containing optical glass waveguide can consequently be matched even by a small increase in the temperature of the planar optical polymer waveguide. In addition, only the propagation constant of the optical field in a silicon-dioxide-containing optical waveguide according to the invention is influenced by the coupling mode between silicon-dioxide waveguide and polymer waveguide.

Abstract: The production of optical waveguides on waveguide bases which, for example, are formed from a correspondingly structured buffer layer, reduces the birefringence which occurs owing to thermally induced stresses during the glass production process. Therefore, the concentration of dopants (for example boron atoms) in the cladding layer can be reduced to achieve a birefringence-free optical component as complete adaptation of the thermal coefficient of expansion of the glass to that of the silicon substrate is no longer necessary. This has the enormous advantage that optical components, which comprise optical waveguides of this type, remain stable relative to external influences for a long time.