20120063484 | DISTRIBUTED REFLECTOR IN A MICRORING RESONATOR - A component having a microring resonator and grating, coupled to a waveguide is described. By selection of the grating period, and other parameters such as the grating-waveguide coupling coefficient, an efficient filter may be designed and constructed. The component may be used in passive devices such as add-drop multiplexers or sensors, or in active devices such as lasers. Designs having essentially no response sidelobes, very narrow effective bandwidths, and fast filter roll-offs may permit compact devices to be produced, when compared with typical distributed sampled Bragg grating structures. | 03-15-2012 |
20140093986 | Optically Monitoring and Controlling Nanoscale Topography - Methods and apparatus for method for characterizing a height profile of a scattering surface relative to a fiducial plane. The scattering surface, which may be an interface between distinct solid, liquid, gaseous or plasma phases, is illuminated with substantially spatially coherent light, and light scattered by the scattering surface is collected and dispersed, such as by a grating, into zeroth- and first-order beams. A spatial Fourier transform of the zeroth- and first-order beams is created, and one of the beams is low-pass filtered. The beams are interfered at a focal plane detector to generate an interferogram, which is transformed to retrieve a spatially resolved quantitative phase image and/or an amplitude image of the scattering surface. Imaging may be performed during an etching process, and may be used to adaptively control a photoetching process in a feedback loop. | 04-03-2014 |