Abstract: An apparatus and method for characterizing the complex coupling coefficient of a multilayered periodic structure either during or after inscription is described. This apparatus is capable of continuously measuring the complex reflectivity at single or multiple wavelengths to a resolution limited by Rayleigh scattering in the waveguide section where the structure is inscribed. The apparatus is also capable of rejecting undesired signals associated with stray reflections in the system and unwanted environmentally induced change in optical path lengths during the inscription procedure. The complex coupling coefficient of the multilayered periodic structure can be derived from the measured complex reflectivity and can reveal errors present in the structure. The complex coupling coefficient can also be used to derive an error signal to enable implementation of a closed loop inscription system capable of inscribing error free multilayer structures.

Abstract: An apparatus and method for characterizing the complex coupling coefficient of a multilayered periodic structure either during or after inscription is described. This apparatus is capable of continuously measuring the complex reflectivity at single or multiple wavelengths to a resolution limited by Rayleigh scattering in the waveguide section where the structure is inscribed. The apparatus is also capable of rejecting undesired signals associated with stray reflections in the system and unwanted environmentally induced change in optical path lengths during the inscription procedure. The complex coupling coefficient of the multilayered periodic structure can be derived from the measured complex reflectivity and can reveal errors present in the structure. The complex coupling coefficient can also be used to derive an error signal to enable implementation of a closed loop inscription system capable of inscribing error free multilayer structures.

Abstract: The device includes two supports and a primary conductive strip. The primary conductive strip includes a neutral surface, a first side, and a second side. The primary conductive strip is connected one of directly and indirectly on the first side to the two supports such that the primary conductive strip is constrained in two dimensions and movable in one dimension. The device also includes a primary distributed feedback fiber laser. The primary distributed feedback fiber laser includes a fiber axis. The primary distributed feedback fiber laser is connected to the primary conductive strip along one of the first side and the second side such that there is a positive distance between the neutral surface of the primary conductive strip and the fiber axis of the primary distributed feedback fiber laser.

Abstract: An apparatus includes a multicore fiber including three cores. The three cores include two pairs of cores, each pair of cores lying in a plane. The planes of the two pairs of cores are non-coplanar. The multicore fiber includes a rosette, the rosette including three coplanar interferometers. Each interferometer of the three interferometers are located in a respective core of the three cores. Each interferometer includes a first reflector and a second reflector. The first reflectors of the rosette are coplanar. The second reflectors of the rosette are coplanar.