Abstract: A modulator for an electrical signal comprises a data input port and a clock frequency input port. The modulator also comprises a first phase shifter for subjecting input clock frequency signals to a phase shift and adapted to keep the phase of an input clock frequency signal aligned with the phase of a data stream which is input at the data input port. The modulator also comprises a first XOR gate with an output port, to which first XOR gate said input ports of the modulator are connected, by means of which a BPSK signal is created at the output port when a first data stream is connected to the data input port and a first clock frequency signal is connected to the clock frequency input port.

Abstract: A system and method for providing polarization-independent optical sampling utilizes a differential group delay (DGD) element to split a sampling pulse source (SPS) into orthogonal components by controlling the state of polarization of the SPS at the DGD element input. The orthogonally-polarized sampling pulse components then each interact with the input optical signal waveform in a polarization-dependent sampling gate, creating two samples for each original sampling pulse. The generated samples are converted into the electrical domain by a photodetector with an impulse response time longer than that associated with the DGD element, resulting in a single impulse response representing the combined energy of the two samples that is independent of the state of polarization of the input optical signal waveform.

Abstract: A system and method for providing polarization-independent optical sampling utilizes a differential group delay (DGD) element to split a sampling pulse source (SPS) into orthogonal components by controlling the state of polarization of the SPS at the DGD element input. The orthogonally-polarized sampling pulse components then each interact with the input optical signal waveform in a polarization-dependent sampling gate, creating two samples for each original sampling pulse. The generated samples are converted into the electrical domain by a photodetector with an impulse response time longer than that associated with the DGD element, resulting in a single impulse response representing the combined energy of the two samples that is independent of the state of polarization of the input optical signal waveform.

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.

Abstract: The present invention relates to a spectrometer module comprising an input, for receiving an incoming optical signal, a variable differential group delay (DGD) element, for applying a variable birefringence retardation to said incoming optical signal, and a detector unit for detecting the power of a signal exiting said variable DGD element, having a defined state of polarization. It also relates to a monitor module, a monitoring unit and a monitoring system, comprising such a spectrometer module for use in monitoring an optical network. Further, the invention relates to a spectrometer device, for spectrometry purposes, comprising a spectrometer module as stated above.

Abstract: The present invention relates to a spectrometer module comprising an input, for receiving an incoming optical signal, a variable differential group delay (DGD) element, for applying a variable birefringence retardation to said incoming optical signal, and a detector unit for detecting the power of a signal exiting said variable DGD element, having a defined state of polarization. It also relates to a monitor module, a monitoring unit and a monitoring system, comprising such a spectrometer module for use in monitoring an optical network.

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.