Abstract: A system for synchronizing unrelated information or reference signals originating from multiple sources. The signals may be in different signal formats or subject to different delays at a receiving device. The system may include a master reference time generator connected to at least one of a plurality of slave reference signal generators via a packet network. The master reference time generator may include a master reference time counter and a sampling device for sampling the master reference time counter. The master reference time generator may encode time data in master reference time packets and feed these packets into the packet network. The slave reference signal generator(s) is adapted to accept the encoded time data as an input to generate a reference signal, the phase of which is calculated based on the time elapsed since an initial time point.

Abstract: A low white frequency noise tunable semiconductor laser source is presented. The laser source includes a single-mode semiconductor laser assembly which generates a laser beam having a tunable frequency over a spectral range of interest. An optical filter is provided in the path of the laser beam. The optical filter has multiple spectral features distributed over the entire spectral range of interest. Each spectral feature has a narrow spectral range. A locking mechanism is further provided and is controllable for locking a spectral alignment between the frequency of the laser beam and any selected one of the spectral features of the optical filter.

Abstract: A method is provided for measuring a factor, called herein the single-port rejection ratio (SPRR), characterizing a balanced detection device. The SPRR is representative of the ratio of the weak differential output current measured under illumination of a single-port of the balanced detection device to the strong measurable differential output current obtained under dual-port illumination. An apparatus for measuring the SPRR is also provided.

Abstract: A low white frequency noise tunable semiconductor laser source is presented. The laser source includes a single-mode semiconductor laser assembly which generates a laser beam having a tunable frequency over a spectral range of interest. An optical filter is provided in the path of the laser beam. The optical filter has multiple spectral features distributed over the entire spectral range of interest. Each spectral feature has a narrow spectral range. A locking mechanism is further provided and is controllable for locking a spectral alignment between the frequency of the laser beam and any selected one of the spectral features of the optical filter.

Abstract: A system replaces the current “Genlock” reference signals and distribution architectures used in media and broadcasting use an IP network and distributed timekeeping service, such as ISO/IEC 61588 or IEEE1588. In such a system, a master and multiple slave devices are used to distribute precision time and phase information to synchronize equipment and systems. The method described herein allows the generation of a signal standard and format with a single distribution system. In addition, the method allows this distribution to be accomplished over an IP network despite the non-deterministic performance of such networks. The method also allows the deterministic generation of signals at slave devices.

Abstract: A method is provided for measuring a factor, called herein the single-port rejection ratio (SPRR), characterizing a balanced detection device. The SPRR is representative of the ratio of the weak differential output current measured under illumination of a single-port of the balanced detection device to the strong measurable differential output current obtained under dual-port illumination. An apparatus for measuring the SPRR is also provided.

Abstract: A system for synchronizing unrelated information or reference signals originating from multiple sources. The signals may be in different signal formats or subject to different delays at a receiving device. The system may include a master reference time generator connected to at least one of a plurality of slave reference signal generators via a packet network. The master reference time generator may include a master reference time counter and a sampling device for sampling the master reference time counter. The master reference time generator may encode time data in master reference time packets and feed these packets into the packet network. The slave reference signal generator(s) is adapted to accept the encoded time data as an input to generate a reference signal, the phase of which is calculated based on the time elapsed since an initial time point.

Abstract: A system replaces the current “Genlock” reference signals and distribution architectures used in media and broadcasting use an IP network and distributed timekeeping service, such as ISO/IEC 61588 or 1EEE1588. In such a system, a master and multiple slave devices are used to distribute precision time and phase information to synchronize equipment and systems. The method described herein allows the generation of a signal standard and format with a single distribution system. In addition, the method allows this distribution to be accomplished over an IP network despite the non-deterministic performance of such networks. The method also allows the deterministic generation of signals at slave devices.

Abstract: A method for manufacturing a complex multi-channel optical grating using a phase mask is presented. A plurality of sub-gratings is designed, each having an individual spectral response designed to produce one of the channels of the multi-channel grating. The target profile of the grating is determined based on the combination of the index profiles of the individual sub-gratings, the target index profile defining a target spectral response of the multi-channel grating. A modified index profile having a smooth apodization profile but providing the same spectral response as the target index profile, at least within a spectral region of interest, is determined and encoded into the phase mask. The phase mask is then used to photoinduce the grating in a photosensitive medium.

Abstract: A method for manufacturing complex gratings masks having phase shifted regions and a holographic set-up for making the same are disclosed. The method, which can be easily automated, allows to produce arbitrary phase shift in holographically recorded gratings with high precision. In a preferred embodiment, the phase is controlled by a fringe locking system with a movable locking detector and a phase measuring device such as a camera for example, thereby allowing to provide a real-time phase locking and a real-time calibration of the set-up.